Proceedings of the KSRS Conference (대한원격탐사학회:학술대회논문집)
Korean Society of Remote Sensing
- Annual
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- 1226-9743(pISSN)
Domain
- Energy/Resources > Resources Exploration/Development/Utilization
2002.10a
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In this study, we investigate the atmospheric environment changes in the aspect of optical remote sensing using surface observation data from 1971 to 2000 of Korea Meteorological Administration. Visibility, spatially averaged over Korean peninsula, is systematically reduced from about 28km to 18km during the last 30 years. It means that atmospheric conditions for the optical remote sensing over Korean peninsula are growing worse and worse due to the degradation of air quality. The 30-year average of cloud amount shows a strong seasonal variation, maximum(75%) in summer and minimum (35%) in autumn. Precipitation also shows a very similar variation pattern with cloud. The temperature and sea level pressure show a opposite seasonal change pattern, maximum(minimum in SLP) in summer and minimum(maximum in SLP) in winter, respectively. Relative humidiy(RH) is one of the variables mostly affected by urbanization or urban heat island. As a results, annual mean RH is decreased from 73% to 68% during last 30 years. When we take into account the favorable and unfavorable factors all together, summer and autumn are the worst and the best season for optical remote sensing in Korea.
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This study introduces the first method that determines tropospheric ozone column directly from a space-based instrument. This method is based on the physical differences in the Total Ozone Mapping Spectrometer (TOMS) measurement as a function of its scan-angle geometry. Tropospheric ozone in September-October exhibits a broad enhancement over South America, the southern Atlantic Ocean, and western South Africa and a minimum over the central Pacific Ocean. Tropical tropospheric ozone south of the equator is higher than north of the equator in September-October, the southern burning season. Conversely, ozone north of the equator is higher in March, the northern burning season. Overall, the ozone over the southern tropics during September-October is significantly higher than over the northern tropics. Abnormally high tropospheric ozone occurs over the western Pacific Ocean during the El Nino season when the ozone amounts are as high as the ozone over the Africa.
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The clear sky radiative forcings of aerosols were evaluated over East Asia. We first investigated optical characteristics of aerosol using sky radiation measurements. An algorithm of Nakajima et al. (1996) is used for retrieving aerosol parameters such as optical thickness,
${\AA}$ ngstr$\"{O}$ m exponent, single scattering albedo, and size distribution from sky-radiation measurements, which then can be used for examining spatial and temporal variations of aerosol. Obtaining aerosol radiative forcing at TOA and surface, a radiative transfer model is used with inputs of obtained aerosol parameters and GMS-5 satellite-based cloud optical properties. Results show that there is a good agreement of simulated downwelling radiative flux at the surface with observation within 10 W m$^{-2}$ rms errors under the clear sky condition. However, a relatively large difference up to 40 W m$^{-2}$ rms error is found under the cloudy sky condition. The computed aerosol radiative forcing at the surface shows downward flux changes ranging from -100 to -170 W m$^{-2}$ per unit aerosol optical thickness at 0.7$\mu$ m. The different values of aerosol radiative forcing among the stations is mainly due to the differences in single scattering albedo ($\omega$ $_{0.7}$ ) and asymmetric parameter (g$_1$ ) related to the geographical and seasonal variations. -
This paper is concerned with a local detection of road on an airborne SAR image. The roads can be characterized by their geometry and radiometry. Roads are assumed as linear, thin, and elongated objects that are darker than their surroundings on an airborne SAR image. With these assumptions, a series of morphological filters are applied and tested successively. This approach is simple and almost non parametric and has been successfully applied to an airborne SAR image.
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Among effective feature extraction methods from the small-patched image set, independent component analysis (ICA) is recently well known stochastic manner to find informative basis images. The ICA simultaneously learns both basis images and independent components using high order statistic manners, because that information underlying between pixels are sensitive to high-order statistic models. The topographic ICA model is adapted in our experiment. This paper deals with an unsupervised classification strategies using learned ICA basis images. The experimental result by proposed classification technique shows superior performance than classic texture analysis techniques for the panchromatic KOMPSAT imagery.
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In order to utilize remote sensed images widely, it is necessary to correct geometrically. Traditional approaches to geometric correction require substantial human operations. Such substantial human operations make geometric correction a laborious and tedious process. In this paper, We introduce concept of GCP(Ground Control Point) Chip and generate a GCP Chip for automatic geometric correction. GCP Chip is small image patch which has a GCP in reference coordinate image. GCP Chip will be used to match new images in geometric correction. We generated GCP chip using Landsat-7 ETM+ panchromatic band image in this study. Henceforth this result will support automatic process in geometric correction.
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Road information is very important for topographic mapping, transportation application, urban planning and other related application fields. Therefore, automatic detection of road networks from spatial imagery, such as aerial photos and satellite imagery can play a central role in road information acquisition. In this paper, we use least squares correlation matching alone for road center tracking and show that it works. We assumed that (bright) road centerlines would be visible in the image. We further assumed that within a same road segment, there would be only small differences in brightness values. This algorithm works by defining a template around a user-given input point, which shall lie on a road centerline, and then by matching the template against the image along the orientation of the road under consideration. Once matching succeeds, new match proceeds by shifting a matched target window further along road orientation at the target window. By repeating the process above, we obtain a series of points, which lie on a road centerline successively. A 1m resolution IKONOS images over Seoul and Daejeon were used for tests. The results showed that this algorithm could extract road centerlines in any orientation and help in fast and exact he ad-up digitization/vectorization of cartographic images.
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Precision correction is the process of geometrically aligning images to a reference coordinate system using GCPs(Ground Control Points). Many applications of remote sensing data, such as change detection, mapping and environmental monitoring, rely on the accuracy of precision correction. However it is a very time consuming and laborious process. It requires GCP collection, the identification of image points and their corresponding reference coordinates. At typical satellite ground stations, GCP collection requires most of man-powers in processing satellite images. A method of automatic registration of satellite images is demanding. In this paper, we propose a new algorithm for automatic precision correction by GCP chips and RANSAC(Random Sample Consensus). The algorithm is divided into two major steps. The first one is the automated generation of ground control points. An automated stereo matching based on normalized cross correlation will be used. We have improved the accuracy of stereo matching by determining the size and shape of match windows according to incidence angle and scene orientation from ancillary data. The second one is the robust estimation of mapping function from control points. We used the RANSAC algorithm for this step and effectively removed the outliers of matching results. We carried out experiments with SPOT images over three test sites which were taken at different time and look-angle with each other. Left image was used to select UP chipsets and right image to match against GCP chipsets and perform automatic registration. In result, we could show that our approach of automated matching and robust estimation worked well for automated registration.
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Satellite image processing software should be able to support interoperability that is to enable consumers, citizens, large and small businesses and governments to make the fullest possible use of the world's spatial data and spatial processing resources. The goal of interoperability is to perform hands-on research, development, testing, fielding, and validation of potential and existing interoperable geoprocessing technologies. In this paper, component based architecture for fast interoperability is designed to maximize interoperability among the OpenGIS components specified in the OpenGIS abstract specifications and implementation specifications and to mix up the OpenGIS components and the fast access mechanism for high performance.
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High-resolution satellite image processing software should be able to ensure accurate, fast, compact data processing in offline or online environment. In this paper, component software for high-resolution satellite image processing is developed using OpenGIS components and real-time data processing architecture. The developed component software is composed of three major packages, which are data provide package, user interface package, and fast data processing package. The data provider package encodes and decodes diverse image/vector data formats and give identical data access methods to developers. The user interface package supports menus, toolbars, dialogs, and events to use easier. The fast data processing package follows the OpenGIS's data processing standards, which can deal with several processors as components with standard procedural functionalities.
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According to glowing computing capacity, software in remote sensing has supported diverse processing interfaces from batch interface to high-end user interactive interface. In this paper, component based visual modeler is developed to process batch jobs for high-end users as well as novices. Visual modeler arranges several node groups which are categorized according to their purposes. These nodes carry out elemental unit processes and can be grouped to model. The model represents user specified job which is composed diverse nodes. User can organize models by connecting diverse nodes according to data flow model specification which rules node's connectivity and direction, etc. Furthermore, user defined models can be together to organize much more complex and large model.
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Mean curvature diffusion (MCD) is a selective smoothing technique that promotes smoothing within a region instead of smoothing across boundaries. By using mean curvature diffusion, noise is eliminated and edges are preserved. In this paper, we propose methods of automatic parameter selection and implementation for the MCD model coupled to min/max flow. The algorithm has been applied to high resolution aerial images and the results show that noise is eliminated and edges are preserved after removal of noise.
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This paper presents a method for line segment extraction for 3-d building reconstruction. Building roofs are described as a set of planar polygonal patches, each of which is extracted by watershed-based image segmentation, line segment matching and coplanar grouping. Coplanar grouping and polygonal patch formation are performed per region by selecting 3-d line segments that are matched using epipolar geometry and flight information. The algorithm has been applied to high resolution aerial images and the results show accurate 3-d building reconstruction.
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In remote sensing, images are acquired over the same area by sensors of different spectral ranges (from the visible to the microwave) and/or with different number, position, and width of spectral bands. These images are generally partially redundant, as they represent the same scene, and partially complementary. For many applications of image classification, the information provided by a single sensor is often incomplete or imprecise resulting in misclassification. Fusion with redundant data can draw more consistent inferences for the interpretation of the scene, and can then improve classification accuracy. The common approach to the classification of multisensor data as a data fusion scheme at pixel level is to concatenate the data into one vector as if they were measurements from a single sensor. The multiband data acquired by a single multispectral sensor or by two or more different sensors are not completely independent, and a certain degree of informative overlap may exist between the observation spaces of the different bands. This dependence may make the data less informative and should be properly modeled in the analysis so that its effect can be eliminated. For modeling and eliminating the effect of such dependence, this study employs a strategy using self and conditional information variation measures. The self information variation reflects the self certainty of the individual bands, while the conditional information variation reflects the degree of dependence of the different bands. One data set might be very less reliable than others in the analysis and even exacerbate the classification results. The unreliable data set should be excluded in the analysis. To account for this, the self information variation is utilized to measure the degrees of reliability. The team of positively dependent bands can gather more information jointly than the team of independent ones. But, when bands are negatively dependent, the combined analysis of these bands may give worse information. Using the conditional information variation measure, the multiband data are split into two or more subsets according the dependence between the bands. Each subsets are classified separately, and a data fusion scheme at decision level is applied to integrate the individual classification results. In this study. a two-level algorithm using hierarchical clustering procedure is used for unsupervised image classification. Hierarchical clustering algorithm is based on similarity measures between all pairs of candidates being considered for merging. In the first level, the image is partitioned as any number of regions which are sets of spatially contiguous pixels so that no union of adjacent regions is statistically uniform. The regions resulted from the low level are clustered into a parsimonious number of groups according to their statistical characteristics. The algorithm has been applied to satellite multispectral data and airbone SAR data.
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This article outlines the capabilities of a viewer component called GridViewer, and proves its reusability. GridViewer was designed for the construction of the image display part of GIS or remote sensing application software, and consequently it is particularly straightforward to closely couple GridViewer with access to very large images. Displaying is performed through pyramid structure, which enables to treat very large dataset up to several gigabytes in size under the limited capability of PC. GridViewer is free from responsibility to handle various formats of raster data files by taking grid coverage, which is designed by OGC to promote interoperability between implementations done by data vendors and software vendors providing analysis and grid processing implementations. GridViewer differs from other such viewer by allowing for clients to extend its function and capability by using small set of methods originally implemented in it. We show its reusability and expandability by applying it in developing application programs performing various functions not supported originally by the GridViewer COM component.
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This paper describes the way to embody the grid coverage and the grid coverage processor which can construct pipelines. The pipeline constructed by the developed grid coverages has internal pipelines that have different resolution and it provides the way of access to very large datasets efficiently. Several operations, such as filtering, image enhancement and band operation, are embedded in the developed grid coverage and grid coverage processor COM components. The practical usefulness of the developed grid coverage and grid coverage processor has been proven by applying them in developing an image processing software for very large images.
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This paper describes a corner matching technique for automatic relative orientation. Automatically matched corner points from stereo aerial images are used to a data set and help to improve automation of relative orientation process. A general corner matching process of overall image to image has very heavy operation and repetitive computation, so very time-consuming. But aerial stereo images are approximately seventy percent overlapped and little rotated. Based this hypothesis, we designed a sectional corner matching technique calculating correlation section by section between stereo images. Although the overlap information is not accurate, if we know it approximately, the matching process can be lighter. Since the size of aerial image is very large, corner extraction process is performed hierarchically by creating image pyramid, and corners extracted are refined at the higher level image. Extracted corners at the final step are matched section by section. Matched corners are filtered using positional information and their relation and distribution. Filtering process is applied over several steps because the thing affecting to get good result-good relative orientation parameter- is not the number of matched corner points but the accuracy of them. Filtered data is filtered one more during the process calculating relative orientation parameters. When the process is finished, we can get the well matched corner points and the refined Von-Gruber areas besides relative orientation parameters. This sectional corner matching technique is efficient by decreasing unnecessarily repetitive operations and contributes to improve automation for relative orientation.
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The mainly used technique to rectify satellite images with distortion is to develop a mathematical relationship between the pixel coordinates on the image and the corresponding points on the ground. By defining the relationship between two coordinate systems, a polynomial model is designed and various linear transformations are used. These GCP based geometric correction has performed overall plane to plane mapping. In the overall plane mapping, overall structure of a scene is considered, but local variation is discarded. The highly variant height of region is resampled with distortion in the rectified image. To solve this problem this paper proposed the TIN-based rectification on a satellite image. The TIN based rectification is good to correct local distortion, but insufficient to reflect overall structure of one scene. So, this paper shows the experimental result and the analysis of each rectification model. It also describes the relationship GCP distribution and rectification model. We can choose a geometric correction model as the structural characteristic of a satellite image and the acquired GCP distribution.
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Classification is considered as one of the processes of extracting attributes from satellite imagery and is one of the usual functions in the commercial satellite image processing software. Accuracy of classification plays a key role in deciding the usage of its results. Many tremendous efforts far the higher accuracy have been done in such fields; training area selection, classification algorithm. Our research is one of these effort in different manners. In this research, we conduct classification using multiple satellite image data and evidential approach. We statistically consider the posterior probabilities and certainty in maximum likelihood classification and methodologically Dempster's orthogonal sums. Unfortunately, accuracy for the whole data sets has not assessed yet, but accuracy assessments in training fields and check fields shows accuracy improvement over 10% in overall accuracy and over 0.1 in kappa index.
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RFM is the sensor model of IKONOS imagery for end-users. IKONOS imagery vendors provide RPC (Rational Polynomial Coefficients), Ration Function Model coefficients for IKONOS, for end-users with imagery. So it is possible that end-users obtain geospatial information in their IKONOS imagery without additional any effort. But there are requirements still fur rigorous 3D positions on RPC user. Provided RPC can not satisfy user and company to generate precision 3D terrain model. In IKONOS imagery, physical sensor modeling is difficult because IKONOS vendors do not provide satellite ephemeris data and abstract sensor modeling requires many GCP well distributed in the whole image as well as other satellite imagery. Therefore RPC modification is better choice. If a few GCP are available, RPC can be modified by method which is introduced in this paper. Study on evaluation modified RPC in IKONOS reports reasonable result. Pseudo GCP generated with vendor's RPC and additional GCP make it possible through sequential solution.
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Satellite Image archiving system requires large storage and long transmission time. A simple and cheap way of overcoming these limitations is to increase the compression ratio. However this requires a feasibility study for accurate applications. Here, a new still image compression standard is being developed, the JPEG2000. It provides lossless and lossy compression, progressive transmission by pixel accuracy and by resolution, region-of-interest coding, user-defined tiling size, random codestream access and processing etc. In this study, we will briefly introduce the JPEG2000 compression standard which provides a new compression technique based on the wavelet technology and offers better compression ratios, and evaluate the compression ratios of JPEG2000 for satellite image by performing various image quality tests. Also, we will compare brief test result using the commercial remote sensing software.
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Recently, DARI implemented the receiving and processing system for MODIS sensor data from NASA EOS satellites (TERRA and AQUA). This paper shows the development strategy considered, system requirement derived, system design, characteristic and test results of processing system. System operation concept and sample image are also provided. Implemented system was proven to be fully operational through lots of pass operations activities from RF signal reception to level-1 processing.
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Detecting simple shaped buildings from 1m-resolution satellite imagery is presented. The proposed algorithm is that first, image features such as edges are detected and then segmentation process is performed with the detected features. It can be result in line primitives. These primitives are linked and grouped by building hypotheses. Proposed building hypotheses restrict a building to simple rectangular shape. And sub-region homogeneity test is performed for finding rooftops of buildings. The proposed algorithm has been tested on IKONOS satellite image with 1m-resolution.
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In this paper we describe techniques for the automated creation of geometric correct 3-D models of the building using two 2-D laser scanners. One of the laser scanners is used for position estimation using a scan matching algorithm, while the other is used to build 3-D models of the facade of the buildings. Those models can be used for virtual reality, tele-presence, digital cinematography and urban planning applications. Results are shown for building models in our campus using real data acquired from two sensors.
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4S-Van is being developed in order to provide the spatial data rapidly and accurately. 4S-Van technique is a system for spatial data construction that is heart of 4S technique. Architecture of 4S-Van system consists of hardware integration part and post-processing part. Hardware part has GPS, INS, color CCD, camera, B/W CCD camera, infrared rays camera, and laser. Software part has GPS/INS integration algorithm, coordinate conversion, lens correction, camera orientation correction, and three dimension position production. In this paper, we suggest that adequate 4S-Van design is needed according to application environment from various test results.
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The types of service using location Information are being various and extending it's domain as wireless internet technology is developing and it's application part is widespread, so it is prospected that LBS (Location-Based Services) will be killer application in wireless internet services. This location information is basic and high value-added information, and this information services make prior GIS (Geography Information System) to be useful to anybody. The acquisition of this location information from moving object is very important part for these LBS. After this, when LBS is familiar to everybody, we can predict that LBS system load is so heavy for the acquisition of so many subscribers and vehicles. Moving object database (MODB) system manages objects like subscribes and vehicles that are moving and have telecommunication terminal checked one's location. MODB is consists of 4 part, moving object location acquisition part, moving object location storage part, moving object query processing part, and moving object application p art. In this MODB system, acquisition of moving object location part must provide guarantee location information as well as reduce telecommunication overhead. In this paper, we study of problems in acquisition a huge number o f moving objects location and design some acquisition strategies to reduce telecommunication overhead. And after implementation these strategies, we estimate performance of this system and quality of information.
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In this paper, we propose Media GIS web service architecture using 3D geographical database and GPS-related data resulted from 4S-Van. We introduce a novel interoperable geographical data service concept; so-called, Virtual World Mapping (VWM) that can map 3D graphic world with real-world video. Our proposed method can easily retrieve geographical in-formation and attributes to reconstruct 3D virtual space according to certain frame in video sequences. Our proposed system architecture also has an advantage that can provide geographical information service with video stream without any image processing procedures. In addition to, describing the details of our components, we present a Media GIS web service system by using GeoVideo Server, which performs VWM technique.
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In this paper, we propose spatial prediction model for landslide hazard mapping that can account for the fuzziness of boundaries in thematic maps showing the different environmental impacts, depending on the scales and the resolutions of them. The fuzziness or uncertainty of boundary is represented in favourability function based on fuzzy object concept and the effects of them are quantitatively evaluated with the help of cross validation procedures. To illustrate the proposed schemes, a case study from Boeun, Korea was carried out. As a result, the proposed schemes are helpful to account for intrinsic uncertainties in categorical maps and can be effectively adopted in spatial prediction models for other purposes.
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One of the fundamental components important to the analysis of spatial objects is to represent topological relationships between spatial features. Users of geographic information systems retrieve a lot of objects from spatial database and analyze their condition by means of topological relationships. The existing methods that represent these relationships have the disadvantage that they have limited information in
$R^2$ . In this paper, we represent and define the topological relationships between 3-dimensional spatial objects using the several representing methods of 2-dimensional features. We use the diverse representing methods, which include the 4-, 9-intersection, dimension extended and calculus-based method. Furthermore, we discuss OGC's topological relationships and operators for 3-dimensional spatial data. -
This paper proposes a way of constructing modern concept of geographic network by interpreting historical geography recorded in old archives such as the Tongdian(通典, Comprehensive Manual) which is one of the important materials in studying old concept of Chinese administrative geography. it is proposed a way of producing geographic network by constructing base network, and by combining and adjusting the constructed networks. The proposed way of construction has been applied for generating a geographic network around Bohai gulf and Sandong peninsula, by using descriptions recorded in the administrative division(州郡典) of the Tongdian.
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This paper describes a framework for extending GIS databases to support moving object data type and query language. The rapid progress of wireless communications, positioning systems, and mobile computing devices have led location-aware applications to be essential components for commercial and industrial systems. Location-aware applications require GIS databases system to represent moving objects and to support querying on the motion properties of objects. For example, fleet management applications may require storage of information about moving vehicles. Also, advanced CRM(Customer Relationship Management) applications may require to store and query the trajectories of mobile phone users. In this trend, maintaining consistent information about the location of continuously moving objects and processing motion-specific queries is challenging problem. We formally define a data model and query language for mobile objects that includes complex evolving spatial structure, and propose core algebra to process the moving object query language. Main profit of proposed moving objects query language and algebra is that proposed model can be constructed on the top of GIS databases.
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Analysis techniques using stereo-photos of object is used widely in close-range-photogrammetry field. but, there is difficulty to use metric camera for specialist. In this study, stereo images were acquired using metric camera and general digital camera about slide in Youngdong area. And they were generated two DEMs based metric camera and digital camera. And it was analyzed the correlation of two DEMs. Therefore, in research that was presented effectiveness of digital camera take the place of metric camera for slope analysis.
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Web GIS (Geographic Information Systems) service systems provide the various GIS services of analyzing and displaying the spatial data with friendly user-interface. These services are expanding the business domain and many users want to access the distributed various spatial data. But, it is difficult to access diverse data sources because of different spatial data format and data access methods. In this paper, we design and implement web GIS services based on the inter-operability and GML (Geography Markup Language) of OGC(Open GIS Consortium) in web distributed environment. Inter-operability provides unique accessing method to distributed data sources based on OLE DB technology of Microsoft. In addition, GML support web GIS services based on XML. We design these GIS services as components using UML (Unified Modeling Language) of an object-oriented modeling language for specifying, visualizing, constructing, and documenting the artifacts of software system. In addition, they also were developed in object-oriented computing environment, and it provides the interoperability, language-independent, easy developing environment as well as re-usability.
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Recently, as the geographic information system (GIS) which searches, manages geographic information is used more widely, there is more requests for some systems which can search and display more actual and realistic information. As a response to these requests, the video geographic information system which connects video data obtained by using cameras and geographic information as it is by displaying the obtained video data is being more popular. However, because most existing video geographic information systems consider video data as an attribute of geographic information or use simple one-way links from geographic information to video data to connect video data with geographic information, they support only displaying video data through searching geographic information. In this paper, we design and implement a video geographic information system which connects video data with geographic information and supports hi-directional search; searching geographic information through searching video data and searching video data through searching geographic information. To do this, we 1) propose an ER data model to represent connection information related to video data, geographic information, 2) propose a process to extract and to construct connection information from video data and geographic information, 3) show a component based system architecture to organize the video geographic information system.
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Recently, location based services, which make use of location information of moving objects, have obtained increasingly high attention. The moving objects are time-evolving spatial objects, that is, their locations are dynamically changed as time varies. Generally, GIS server stores and manages the spatial objects, of which locations are rarely changed. The traditional GIS server, however, has a difficulty to manage the moving objects, due to the fact of locations being frequently changed and the trajectory information (past locations of moving objects) being managed. In this paper, we have designed a moving object server, which stores and manages the locations in order to support various location based services. The moving object server is composed of a location acquisition component, a location storage component, and a location query component. The contribution of this paper is that we integrate the each work for location acquisition, storage, and query into a moving objects server.
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Recently, owing to performance elevation of telecommunication technology, increase of wireless internet's subscriber and diffusion of wireless device, Interest about LBS (Location Based Service) which take advantage of user's location information and can receive information in concerning with user's location is increasing rapidly. So, MOMS (Moving Object Management System) that manage user's location information is required compulsorily to provide location base service. LBS of childhood such as service to find a friend need only current location, but to provide high-quality service in connection with Data Mining, CRM, We must be able to manage location information of past. In this paper, we design distributed manage system to insert and search Moving Object in a large amount. It has been consisted of CLIM (Current Location Information Manager), PLIM (Past-Location Information Manager) and BLIM (Distributed Location Information Manager). CLIM and PLIM prove performance of searching data by using spatiotemporal-index. DLIM distribute an enormous amount of location data to various database. Thus it keeps load-balance, regulates overload and manage a huge number of location information efficiently.
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KIGAM(Korea Institute of Geoscience and Mineral Resources) has finished to digitalize geological maps of 1/50, 000 scales in 1999. This project is supported by the Korea Ministry of Information and Communication under the name of "Knowledge and Information Resources Management Project". And via geo-clearing house, KIGAM has begun to sale the geological maps that are modified more correctly now June, 2002. The objective of this paper is to evaluate the status of digital geological mapping in Korea. And to introduce Clearing House and future plans of KIGAM.
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In this paper, we suggest a new spatial information system called video GIS where video is used for spatial data construction and is integrated with map. We develop a prototype system of video GIS and apply it to roadside facility management. The main functions supported by the suggested system are data collection, coordinate calculation and conversion, data construction, analysis, searching, and browsing. The stereo images and corresponding position data are collected by a vehicle named 4S-Van that has GPS, IMU, and cameras. The 3-D coordinates of the objects in the images, such as road sign, signal lamp, and building, can be calculated and constructed from the collected data. The spatial objects are displayed on both image and map, and can be searched and browsed, which enables visual and realistic browsing and management of spatial objects. Compared to conventional field survey used in roadside facility management, the method enables faster, easier, and more efficient construction of spatial data. The suggested video GIS can be applied not only to roadside facility management but also to many similar projects of central or local governments that are related to GIS.
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The paper introduces the application of flood monitoring and assessment by remote sensing and GIS in china and describes the frame of operational system for practical performance of flood disaster mitigation. In addition, The operational system for flood monitoring and assessment in RSTAC/ MWR and its application in the floods of 1998,1999 in china are introduced.
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In this paper forest fire statistical information management system is constructed on web environment using web based GIS(Geographic Information System) technology. Though this system, general users can easily access forest fire statistical information and obtain them in visual method such as maps, graphs, and text if they have web browsers. Moreover, officials related to forest fire can easily control and manage all information in domestic by accessing input interface, retrieval interface, and out interface. In order to implement this system, IIS 5.0 of Microsoft is used as web server and Oracle 8i and ASP(Active Server Page) are used for database construction and dynamic web page operation, respectively. Also, Arc IMS of ESRI is used to serve map data using Java and HTML as system development language. Through this system, general users can obtain the whole information related to forest fire visually in real time also recognize forest fire prevention. In addition, Forest officials can manage the domestic forest resource and control forest fire dangerous area efficiently and scientifically by analyzing and retrieving huge forest data through this system. So, they can save their manpower, time and cost to collect and manage data.
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From this year, KIGAM, one of Korean government-supported research institutes, has started new national program for digital geologic/natural resources infrastructure building. The goal of this program is to prepare digitally oriented infrastructure for practical digital database building, management, and public services of numerous types of paper maps related to geo-scientific resources or geologic thematic map sets: hydro-geologic map, applied geologic map, geo-chemical map, airborne radiometric/magnetic map, coal geologic map and off-shelf bathymetry map and so forth. As for digital infrastructure, several research issues in this topic are composed of: ISP (Information Strategy Planning), geo-framework modeling of each map set, pilot database building, cyber geo-mineral directory service system, and web based geologic information retrieval system upgrade which services Korean digital geologic maps scaled 1:50K. In this study, UML (Unified Modeling Language)-based data modeling of geo-data sets by and in KIGAM, among them, is mainly discussed, and its results are also presented in the viewpoint of digital geo-modeling ISP. It is expected this model is further progressed with the purpose of being a guidance or framework modeling for geologic thematic mapping and practical database building, as well as other types of national thematic map database building.
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The high prices of satellite images prevent researchers from studying remote sensing and most non-professional people doesn't have the simple and easy solutions for the manipulation of satellite images. "Integrated Management of Satellite Imagery Information" project which will be promoted by ETRI (Electronics and Telecommunications Research Institute) will provide the solutions for the above mentioned problems. We will introduce the archiving center in this study. This includes the data construction, storage, management and distribution. We first review the background for this archiving center and introduce the interior and foreign institutes which archive and distribute satellite images. We review our H/W system and S/W system briefly. Finally, the further service of our project will be suggested. Since we will distribute the satellite images (Landsat, SPOT, JERS, Corona, Kompast-1) and will receive Landsat7 ETM+ in 2003 you, this will help the professional work dealing with the satellite image and attract the non-professional people for simple and easy manipulation solutions of satellite image.
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EOC (Electro-Optical Camera) of KOMPSAT-1 (Korea Multi-Purpose SATellite) has been producing land imageries of the world since January 2000. After image data are acquired by EOC, they are transmitted from satellite to ground via X-band RF signal. Then, EOC image data are generated and pass through radiometric and geometric corrections to generate standard products of EOC images. After radiometric correction on EOC image data, Modulation Transfer Function (MTF) compensation is applicable on EOC images with user's request for better image quality. MTF compensation is concerned with filtering EOC images to minimize the effect of degradations. For Image Receiving and Processing System (IRPE) at KOMPSAT Ground Station (KGS), Wiener filter is used in MTF compensation for EOC images. If the Pointing Spread Function (PSF) of EOC system is known, signal-to-noise power spectra ratio is the only factor in the determination of Wiener filter. In this paper, MTF compensation in IRPE at KGS is introduced and MTF compensated EOC 1R images are generated using Wiener filters with various signal-to-noise power spectra ratios. MTF compensated EOC 1R images are correlated with EOC 1R images for observing linearities between them. As a result, the effect of signal-to-noise power spectra ratio is shown on MTF compensated EOC 1R images.
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Relationship between chlorophyll a in the East China Sea and spectral bands (412, 443,490, (510), 555, (676,765) in) of OSMI (Ocean Scanning Multi-Spectral Imager) including the profile multi-spectral radiometer (PRR-800) was studied. The values of remote sensing reflectance (Rrs) at the bands corresponding to the field chlorophyll a in α in the East China Sea were much higher than those in clear waters off California, USA. In case of the particle absorptions related to the chlorophyll a concentration at the spectral bands (440, 670 nm) were much higher in the East China Sea than the ones in the clean waters off California. The normalized water leaving radiances (nLw) at 412, 443, 490, 555 m of OSMI and field chlorophyll a in the East China Sea were correlated each other. According to the results, the relationship between field chlorophyll a and nLw 410 m in OSMI bands was the lowest, whereas that between the field chlorophyll a and nLw 555 nm in the bands was the highest. Reciprocal action between the field chlorophyll a and the band ratio of the OSMI bands (nLw410/nLw555, nLw443/nLw555, nLw490/nLw555) was also studied. Correlation between the chlorophyll a and the band ratio (nLw490/nLw555) was highest in the OSMI bands. Relationship between the chlorophyll a and the ratio (nLw443/nLw555) was higher than one in the nLw410/nLw555. The difference in the estimated chlorophyll α (mg/m3) between OSMI and SeaWiFS (Sea Viewing Wide Field-of-View Sensor) at the special observing stations in the northern eastern sea of Jeju Island in february 25, 2002 was about less than 0.3 mg/m3 within 3 hours. It is suggested that OC2 (ocean color chlorophyll 2 algorithm) be used to get much better estimation of chlorophyll α from OSMI than the ones from the updated algorithms as OC4.
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Much effort has been made in the radiometric calibration of the ocean scanning multispectral imager (OSMI) since after the successful launch of KOMPSAT-1 in 1999. A series of calibration coefficients for OSMI detectors were obtained in collaboration with the NASA Sensor Intercomparison and Merger for Biological and Interdisciplinary (SIMBIOS) project office. In this study, we compare the OSMI level-2 products (e.g., chlorophyll-a concentration) calculated from the NASA cross-calibration coefficients with the SeaWiFS counterparts. Sample study areas are some of diagonostic data sites recommended by the SIMBIOS working group. We will present the preliminary results of this comparative study.
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A spherical Earth surface is used fur realistic analysis of the geometrical performance characteristics about the variation of satellite altitude and 2-dimensional line-of-sight(LOS) tilt angle in a satellite imager using Time Delay and Integration(TDI) technique with fixed integration time. In the spherical Earth surface model TDI synchronization using LOS tilt is investigated as a solution to compensate geometric performance degradation due to altitude decrease. This result can be used fur a TDI CCD imager with variable integration time in a certain as well.
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This research will examine into the capabilities of KOMPSAI-1 EOC image application in the field of urban environment and at the same time, with that as its foundation, come to understand the urban changes of the study areas. This research is constructed in three stages: Firstly, for application of change detection techniques, which utilizes multi-temporal remotely sensed data, the data normalization process is carried out. Secondly, change detection method is applied fur the systematic monitoring of land use changes, which utilizes multi-temporal EOC images. Lastly, by using the results of the application of land use changes, the existing land use map is updated. Consequently, the land-use change patterns are monitored, which utilize multi-temporal panchromatic EOC image data; and application potentials of ancillary data fur updating existing data can be presented. In this research, with the use of the land use change, monitoring of urban growth has been carried out, and the potential for the application of KOMPSAT-1 EOC images and the scope of application was examined. Henceforth, the future expansion of the scope of application of KOMPSAT-1 EOC image is anticipated.
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The DLS(Data Link System) is located in the PDTS(Payload Data Transmission Subsystem) of KOMPSAT-II, and its main function is to provide communication link with Ground Segment as a space segment. DLS receive the data of MSC, OBC from DCSU(Data Compression Storage Unit) and transmit to the Ground Station by X-Band RF link. DLS is consist of CCU(Channel Coding Unit), QTX(QPSK Transmitter, ASU(Antenna Switch Unit) CCU makes a packet for communication after several kind of data processing such like Ciphering, RS Coding. QTX transmit PDTS data by OQPSK. Modulation. ASU is the unit for reliability of antenna switching. So, DLS's function is consists of ciphering, RS coding, CCSDS packetizing, randomizing, modulation and switching to antenna. These DLS's functions are controlled by PMU(Payload Management Unit). All commands to DLS are sent by PMU and all telemetries of DLS are sent to the PMU. The PMU receives commands from OBC and sends telemetries to the OBC. The OBC communicates with Ground Station by S-Band RF link. This paper presents the on-orbit DLS operation concept through the ground segment.
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Under the hostile influence of the extreme space environmental conditions due to the deep space and direct solar flux, the thermal control in space applications is especially of major importance. There are tight temperature range restrictions for electro-optical elements while on the other hand there are low power consumption requirements due to the limited energy sources on the spacecraft. So, we usually have strong requirement of thermal and power control module in space applications. In this paper, the design concept of a thermal and power control module in the MSC(Multi-Spectral Camera) system which will be a payload on KOMPSATII is described in terms of H/W & S/W. This thermal and power control module, called THTM(Thermal and Telemetry Module) in MSC, resides inside the PMU(Payload Management Unit) which is responsible for the proper management of the MSC payload for controlling and monitoring the temperature insides the EOS(Electro-Optic System) and gathering all the analog telemetry from all the MSC sub-units, etc. Particularly, the designed heater controller has the special mode of "duty cycle" in addition to normal closed loop control mode as usual. THTM controls heaters in open loop according to on/off set time designed through analysis in duty cycle mode in case of all thermistor failure whereas it controls heaters by comparing the thermistor value to temperature based on closed loop in normal mode. And a designed THTM provides a checking and protection method against the failure in thermal control command using the test pulse in command itself.
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This paper shows the desist concept of an ATS(Antenna Tracking Software) to control the movement of the MSC(Multi-Spectral Camera) antenna. The MSC has a two-axes directional X-band antenna for image transmission to KGS(KOMSAT2 Ground Station). The main objective of the ATS is to drive the APM(Antenna Pointing Mechanism) to the required elevation and the azimuth position according to an appropriate TPF(Tracking Parameter File). The ATS is implemented as one task of the SBC(Single Board Computer) software, which uses VxWorks as a real time OS. The ATS has several operational modes such as STANDBY mode, First EL mode, First AZ mode, Normal Operation mode, and so on. The ATS uses two PI controllers fur the velocity and the position loop respectively, to satisfy the requirements specification. In order to show the feasibility of the described design concept, the various simulations and the experiments are performed under specific test configuration.
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MSC(Multi-Spectral Camera) is a main payload of KOMPSAT(Korea Multi-Purpose Satellite)-II which will be launched in 2004. MSC will perform his mission with the GSD(Ground Sample Distance) of 1m, swath width of 15km and spectral range of 450nm~900nm at the altitude of 685km. MSC consists of three main subsystems. One is EOS(Electro-Optics Subsystem), another is PMU(Payload Management Unit) and the other is PDTS(Payload Data Transmission Subsystem). There is an SBC(Single Board Computer) in the PW to control all the other units and SBC software performs the interface with spacecraft and control all MSC sub-units. SBC software consists of a lot of tasks and manages them with the time criticalness. All tasks are designed to be scheduled and executed at the predetermined time in order to make sure that the mission of MSC system is achieved successfully. In this paper, the real-time task scheduling of the SBC software will be described and analyzed.
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The Earth's magnetic field acquired from KOMPSAT-1's TAM (Three-Axis Magnetometer) between June 19th and 21st 2000 was analyzed. The TAM, one of the KOMPSAT-1's Attitude and Orbit Control Subsystems, plays an important role in determining and controlling the satellite's attitude. This also can provide new insight on the Earth's magnetic field. By transforming the satellite coordinate from ECI to ECEF, spherical coordinate of total magnetic field was achieved. These data were grouped into dusk (ascending) and dawn (descending) data sets, based on their local magnetic times. This partitioning is essential for performing 1-D WCA (Wavenumber Correlation Analysis). Also, this enhances the perception of external fields in the Kompsat-1's TAM magnetic maps that were compiled according to different local. The dusk and dawn data are processed independently and then merged to produce a total field magnetic anomaly map. To extract static and dynamic components, the 1-D and 2-D WCAs were applied to the sub-parallel neighboring tracks and dawn-dusk data sets. The static components were compared with the IGRF, the global spherical harmonic magnetic field model. The static and dynamic components were analyzed in terms of corefield, external, and crustal signals based on their origins.
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The International Space Station (ISS) offers research opportunities for researchers in the field of remote sensing to conduct world-class activities in Low Earth Orbit. ISS provides the facilities to place and operate research experiments in a variety of fields, providing investigators opportunities to perform research and Earth observation. This paper is intended to give the reader an introduction to the ISS utilization and the capabilities for remote sensing research that are being implemented through the development of research facilities. We hope that reader will consider what kind of payloads could be developed to take advantage of facilities, and will consider proposing remote sensing research on the ISS.
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As Asian Dust's damage and negative effects increase, the need to investigate the weather and surroundings of the source of Asian Dust has been raised. I tried to indicate the source origin and watch changing process of the plants, weather elements in those areas by the means of NOAA AVHRR NOVI and NCEP data.
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This paper describes the study methods of identifying forest vegetation types, based on this study, forest vegetation classification method based on vegetation index is proposed. According to reflectance data of vegetation canopy and soil line equation NIR=1.506R+0.0076 in Jingyuetan, Changchun, China, many vegetation index are calculated and analyzed. The relationships between vegetation index and vegetation types are that PVI identifies broadleaf forest and conifer forest the most easily, the next is TSAVI and MSAVI, but their calculation is complex. RVI values of different conifer trees vary obviously, so RVI can classify conifer trees. In a word, combination of PVI and RVI is evaluated to classify different vegetation types.
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The purpose of this study is to develop landslide susceptibility analysis techniques using artificial neural network and to apply the newly developed techniques to the study area of Boun in Korea. Landslide locations were identified in the study area from interpretation of aerial photographs, field survey data, and a spatial database of the topography, soil type, timber cover, geology and land use. The landslide-related factors (slope, aspect, curvature, topographic type, soil texture, soil material, soil drainage, soil effective thickness, timber type, timber age, and timber diameter, timber density, geology and land use) were extracted from the spatial database. Using those factors, landslide susceptibility was analyzed by artificial neural network methods. For this, the weights of each factor were determinated in 3 cases by the backpropagation method, which is a type of artificial neural network method. Then the landslide susceptibility indexes were calculated and the susceptibility maps were made with a GIS program. The results of the landslide susceptibility maps were verified and compared using landslide location data. A GIS was used to efficiently analyze the vast amount of data, and an artificial neural network was turned out be an effective tool to maintain precision and accuracy.
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Masan barber was situated in S.Korean southern central coast. And it is contributing greatly in S.korea's economy development to international trading port of Heaven's blessing that possess natural, geographical situation. Also, because there are Masan free tax area and chanwon heavy industrial complex, sachon air industrial complex etc. on back, it is important permanency in our country. Specially, because inland transport routes such as southern highway, Guma highway and national road system are developed well, the importance is very high. Masan harbor 1899.05.01 be that opened, the 1st and 2nd (central pier) was build 1938∼1944 year, and the 3rd pier was 1973∼1978 year. the 4th pier was 1974∼1983 year, 5th pier was 1984∼1988, 6th pier (west pier) was 1985∼1992 year. it was developed over 100 years. But, it did great many harbor and bay development of last 100 yens but research about coastline change and seashore reclamation is insufficient. Therefore, this research executed research about coastline change of Masan bay of last 100 years, In this study, we analyzed aerial photographs and tide data for the past 100 years using digital aerial photo analysis and GIS techniques for each 3-year interval. We abstracted beach DEM (digital elevation model) and ortho aerial photographs, and conducted a space analysis. As a result, we were able to identify changes in the area As a result, we drew 10 years cycle coastline change of Masan bay. and we can detect bay coastal line change and calculate refill rate.
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Damage to forest trees, caused by wildfire, changes their spectral reflectance signature. This factor led to the initiation of a research project at the Remote Sensing & GIS Laboratory, Kookmin University, to determine if multispectral data acquired by IKONOS could provide fire scar and bum severity mapping. This paper will present detail mapping of burned areas in the eastern coast of Korea with IKONOS imagery. In addition, a single post-burn Landsat-7 ETM+ data was used to compare with IKONOS, the study area. Burn severity map based on IKONOS image was found to be affected by strong topographic illumination effects in the mountain forest. But it has better the delineation of the bum-scarred area. In this study the NDVI was analyzed for geometric illumination conditions influenced by topography(slop, aspect and elevation) and shadow(solar elevation and azimuth angle).
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Change Detection is a useful technology that can be applied to various fields, taking temporal change information with the comparison and analysis among multi-temporal satellite images. Especially, Change Detection that utilizes high-resolution satellite imagery can be implemented to extract useful change information for many purposes, such as the environmental inspection, the circumstantial analysis of disaster damage, the inspection of illegal building, and the military use, which cannot be achieved by low- or middle-resolution satellite imagery. However, because of the special characteristics that result from high-resolution satellite imagery, it cannot use a pixel-based method that is used for low-resolution satellite imagery. Therefore, it must be used a feature-based algorithm based on the geographical and morphological feature. This paper presents the system that builds the change map by digitizing the boundary of the changed object. In this system, we can make the change map using manual or semi-automatic digitizing through the user interface implemented with a floating window that enables to detect the sign of the change, such as the construction or dismantlement, more efficiently.
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Real-time flood submerged area map provides important scientific basis for the decision-making of flood control and relieving disaster. Taking the Wuhan area as an example, this article gives out a image interpretation method under influence of flood, and describes real-time or quasi-real-time flood submerged area map by using the integration of ERS-2 SAR image and LANDSAT TM image in support of remote sensing images process software ERDAS.
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DGPS(Differential Global Positioning System) and RTK(RealTime Kinematic) is in one of today's most widely used surveying techniques. But It's use is restricted by the distance between reference station and rover station and it is difficult to process data in realtime by it's own orgnizational limitation in precise measurement of positioning. To meet these new demands, In This paper, new DGPS and RTK correction data services through Internet and PSTN(Public Switched Telephony Network) have been proposed. For this purpose, we implemented performance a DGPS and RTK error correction data transmission system for long-distance using the internet and PSTN network which allows a mobile user to increase the distance at which the rover receiver is located from the reference in realtime. and we analyzed and compared DGPS and RTK performance by experiments through the Internet and PSTN network with the distance and the time.
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This study has been accomplished as a experimental study for field application of 3D Perspective Image Map creation using Digital Topographical Map and based on the Ortho-Projection Image which is generated from Satellite Overlay Images and the precise Relative Coordinates of longitude, latitude and altitude which is corrected by GCP(Ground Control Point). AS to Contour Lines Map which is created by Coordinate conversion of 1:5,000 Topographical Map, we firstly made Satellite Image Map to substitute for Digital Topographical Map through overlapping the original images on top of each Ortho-Projection Image created and checking the accuracy. In addition to 3D Image Map creation for 3D Terrain analysis of a target district, Slope Gradient Analysis, Aspect Analysis and Terrain Elevation Model generation, multidirectional 3D Image generation by DEM can be carried out through this study. This study is to develop a mapping technology with which we can generate 3D Satellite Images of a target district through the composition of Digital Maps and Facility Blueprint and arbitrarily create 3D Perspective Images of the target district from any view point.
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Choi, Jun-Ho;Kim, Sung-Hyun;Kang, Gum-Sil;Park, Hyuk;Choi, Seh-Wan;Jiang, Jing-Shan;Kim, Yong-Hoon 297
The subsystems of two channel correlation radiometer such as RF front-end, IF and LF unit, LO unit, software based I/Q demodulator and complex correlator are characterized and their performance is analyzed in this paper. The limited hardware calibration method and receiver design consideration are discussed. The receiver architecture of 37GHz correlation radiometer is integrated. The designed radiometer employs a single-sideband superheterodyne receiver. The center frequency of the radiometer is 37 GHz and IF center frequency is 1.95 GHz with the equivalent noise bandwidth of 79.6 MHz. The receiver has less than 4.2 dB noise figure which is calculated by the Y-factor method and its gain can be adjusted from 60 dB to 80 dB. -
Although Synthetic Aperture Radar(SAR) is a very powerful and attractive tool, automatic interpretation of SAR images is extremely difficult because of several reason. Spatially, speckle noise reduction in SAR images is important step to interpret the SAR image at the preprocessing step. The speckle noise in SAR images is modeled to be multiplicative, and therefore, a signal-dependent noise. So, it has deflated many image-denoising algorithms that are based on additive noise model. In this paper, we propose an adaptive wavelet shrinkage method for speckle noise reduction in SAR images by analyzing the high frequency level in detail. We first decompose minutely the high frequency level to analyze the noise level. And then, we determine the weighting threshold value per the level, and layer. Finally, using those weighting threshold, we produce the efficient wavelet shrinkage method. So, this method not only reduces the speckle noise, but also preserves image detail and sharpness.
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Radar interferometric phase is sensitive to both ground topography and coherent surface displacement. The basic tactics of differential interferometric synthetic aperture radar (DInSAR) technique are to separate the two effects. Applications of DInSAR to Duk-Po area in Busan were studied. In the study area, an abrupt subsidence, possibly caused by sub-way construction, was observed by JERS-1 SAR interferometry. Differential interferograms were generated using twenty-three JERS-1 SAR data acquired between April 24, 1992, and August 7, 1998. Because the area is relatively flat with little topographic relief the topographic effects were not removed. A phase filtering and interferogram techniques were applied to increase fringe clarity as well as to decrease decorrelation error. The stacking improves the quality of interferograms especially when the displacement is discontinuous. The interferograms clearly show the evidence of subsidence along Duk-Po subway railroad. These results demonstrate that the interferogram stacking technique can improve the detectability of radar interferometry to an abrupt displacement and DInSAR is useful to geological engineering applications.
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Satellite radar interferometry data shows a strong coherent signal on oyster sea farms where artificial structures installed on the bottom. We obtained 21 highly coherent interferograms from eleven JERS-1 SAR data sets despite of large orbital baseline (~2 km) or large temporal baseline (~l year). The phases observed in sea farms are probably induced by double bouncing on sea surface, and consequently reveal a tide height variation. To restore the absolute sea level changes we counted the number of wrapping by exploiting the intensity of backscattering. Backscattering intensity is closely correlated with the change in water surface height, while interferometry gives the detailed variation within the limit of 2
$\pi$ (or 15.3 cm). Comparing the radar measurements with the tide gauge records yielded a correlation coefficient of 0.96 and an ms error of 6.0 cm. The results demostrate that radar interferometry is promising to measure sea level. -
Dramatic changes in the patterns of satellite-derived pigment concentrations, sea-level height anomaly, sea surface temperature anomaly, and zonal wind anomaly are observed during the 1997-1998 El Nino. By some measures, the 1997-1998 El Nino was the strongest of the 20
$^{th}$ century. A very strong El Nino developed during 1997 and matured late in the year. A dramatic recovery occurred in mid-1998 and led to a La Nina conditions. The largest spatial extent of the phytoplankton bloom was followed recovery from El Nino over the equatorial Pacific. The evolution towards a warm episode (El Nino) continued in the equatorial Pacific from March 2002 and further development toward mature El Nino conditions may be possible in late 2002. The OSMI (Ocean Scanning Multispectral Imager) data can be used for detection of dramatic changes in the patterns of pigment concentration during next El Nino. -
The thermal effluent discharged from nuclear power plants can affect the offshore ecosystem change. The ability of measuring sea surface temperature in high resolution with Airborne MSS thermal spectral band(8.5
$\mu$ m ~ 12.5$\mu$ m) and Landsat ETM+(10.4$\mu$ m ~ 12.5$\mu$ m) gives us an information of spread range of thermal effluent. This information can be used as one of major factors fur analyzing the impact of the fish farm damage around the nuclear power plants. Every season from November 1999, this research has been conducted to investigate the extent of diffusion of thermal effluent discharged from KoRi, UlJin and WolSung Nuclear Power Plant located at the coastline of the East Sea of Korea. -
The combination of Multi-Beam Echo Sounder swath bathymetry and high-resolution towed Sidescan sonar provides a powerful method of examination about hydrographic survey results. In this paper, we investigate the fast method of 3D bathymetric reconstruction with the Digital Sidescan sonar(Benthos SIS 1500) and Shallow Multi-Beam Echo Sounder(Reson Seabat 8125). The Seabat 8125 is a 455KHz high resolution focused Multibeam echo sounder(MBES) system which measures the relative water depth across a wide swath perpendicular to a vessel's track. The Benthos SIS1500 is a chirp(nominal fq. 200KHz) sonar which map the topographical features & sediment texture of ocean bottom using backscattered amplitude. We generates the very large 3D bathymetric texture mapping model with the Helical System's HHViewer and describes additional benefits of combining MBES and Sidescan Sonar imagery, the removal of geometric distortions in the model and a deterministic sounding noise.
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Satellite positioning technology has been widely used in all kinds of military and civil land, marine, space and aeronautical target positioning tasks, navigation activities and accurate surveying measurements since 90s in the last century due to it advantage in providing all-weather, real-time, three dimensional and high precision positioning information, as well as speed and accurate timing information. By now, it has already formed a new hi-tech industry basically. This paper briefly reviews the development of the global satellite positioning and navigation technologies including the basic information of China′s "Plough navigation system", introduces the history of satellite positioning technology and its major application fields as well as the status quo of this being industrialized trade in China, gives an account of the writers′ vision for the application and prospect of the satellite positioning technologies in China, and approaches the tactics and stresses of the satellite positioning technology′s application and its industrialization future in China.
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Monitoring of wave height is important primarily to reduce storm risks at sea and along the coast. Wave heights in recent years have increased 50% for the last 40 years, thus requiring intensive monitoring. Satellite altimetry offers a powerful tool for regular and extensive monitoring of the wave height. We extracted significant wave height (SWH) using several altimeter missions from 1987-1995 over the Northwest Pacific and compared with ECMWF reanalysis (ERA) products. For large wave heights > 2.5 m, the ERA wave heights are smaller than the altimetric ones, while for small wave heights the ERA wave heights are larger. Comparison in SWH between altimetric derivations and ERA model products shows the discrepancy of 0.46-0.21
$\times$ SWH(m). -
Toward more accurate determination of the water cycle in association with climate variability and change as well as baseline data on the impacts of this variability on water resources, the Coordinated Enhanced Observing Period (CEOP) was launched on July 1,2001. The preliminary data period, EOP-1, was implemented from July to September in 2001. The first annual enhanced observing period, EOP-3, is going to start on October 1,2002. CEOP is seeking to achieve a database of common measurements from both in situ and satellite remote sensing, model output, and four-dimensional data analyses (4DDA; including global and regional reanalyses) for a specified period. In this context a number of carefully selected reference stations are linked closely with the existing network of observing sites involved in the GEWEX Continental Scale Experiments, which are distributed across the world. The initial step of CEOP is to develop a pilot global hydro-climatological dataset with global consistency under the climate variability that can be used to help validate satellite hydrology products and evaluate, develop and eventually predict water and energy cycle processes in global and regional models. Based on the dataset, we will address the studies on the inter-comparison and inter-connectivity of the monsoon systems and regional water and energy budget, and a path to down-scaling from the global climate to local water resources, as the second step.
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The Moderate Resolution Imaging Spectroradiometer (MODIS) on the Earth Observing System (EOS) Terra and Aqua satellites, launched in 1999 and 2002, is directly received by Korea Aerospace Research Institute (KARI) ground station facility. BURI engineers develop a system to receive direct broadcast downlink from MODIS to provide near-realtime, remotely-sensed, spaceborne data to the user community in Korea. MODIS scans a swath width of 2330 km that is sufficiently wide to cover Korean peninsular, Yellow and East Sea at once. The MODIS has 36 spectral bands between 0.415 fm and 14.235
$\mu$ m, i.e. through the visible into the thermal infrared. MODIS has been observed active fires, floods, smoke transport, dust storms, severe storms since February of 2000. The KARI is preparing for distribution of direct broadcasted MODIS data to users in Korea. The MODIS database system will be designed and developed by KARI engineer for data service from year of 2003. MODIS data user group will be organized from$\.{O}$ ctober to December 2002. -
Some interaction characteristics, i.e., light scattering characteristics, of infrared (IR) radiation with small ice crystals are investigated systematically by using the exact T-matrix approach. Some important facts are obtained, which reveal, especially, that the combination of both the 25 and 3.979
$\mu$ m together has some advantages and potential applications for remote sensing of cirrus and other ice clouds. A new far-IR channel at the wavelength of 25$\mu$ m is proposed. -
In order to find horizontal and vertical precipitation structure in Korean peninsula, we use ground-based radar, and Automatic Weather Station (AWS) data. Radar data was selected for rain events in the Pusan and Jindo in Korea, during the spring and summer season of 2002. AWS point gauge measurements are analyzed as part of spatial structure of precipitation. TRMM/PR and ground-based radar is used vertical correlation. The results showed, as expected that the correlation decreased rapidly with distance.
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Rain-rate retrieval using the NOAA/AMSU (Advanced Microwave Sounding Unit) (Zaho et al., 2001) has been implemented at METRI/KMA since 2001. Here, we present the results of the AMSU derived rain-rate and validation result, especially for the rainfall associated with the tropical cyclone for 2001. For the validation, we use rain-rate derived from the ground based radar and/or rainfall observation from the rain gauge in Korea. We estimate the bias score, threat score, bias, RMSE and correlation coefficient for total of 16 tropical cyclone cases. Bias score shows around 1.3 and it increases with the increasing threshold value of rain-rate, while the threat score extends from 0.4 to 0.6 with the increasing threshold value of precipitation. The averaged rain-rate for at all 16 cases is 3.96mm/hr and 1.41mm/hr for the retrieved from AMSU and the ground observation, respectively. On the other hand, AMSU rain-rate shows a much better agreement with the ground based observation over inner part of tropical cyclone than over the outer part (Correlation coefficient for convective region is about 0.7, while it is only about 0.3 over the stratiform region). The larger discrepancy of tile correlation coefficient with the different part of the tropical cyclone is partly due to the time difference in between ice water path and surface rainfall. This results indicates that it might be better to develop the algorithm for different rain classes such as convective and stratiform.
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Cloud-to ground lightning and total precipitation over Korean peninsula during the summer monsoon season are studied extensively with a special emphasis on the characteristics of convective precipitation. Ten years (1988-1997) lightning and rainfall data and a temporal and spatial scale of one month and 10
$^2$ km$^2$ respectively are used to calculate the monthly number of CG lightning flash count. Monsoonal convective activity is higher over the west coast with maxima at two different regions, one in the northern part which increases nortwestward and the other is at the middle west coast of Korea increasing towards the west coast. East coast represents the minimum value of monsoonal convective activity. In the east coast of Korean peninsula, particularly in the region east of Tae-back mountain, the value of Rain yield, (which is defined as the ratio of total precipitation to CG flash count over a common area), is maximum with an average value of 3$\times$ 10$^{8}$ kg fl$^{-1}$ , while the minimum value of rain yield is occurred in the west of Tae-back mountain, with an average value of 0.8$\times$ 10$^{8}$ kg fl$^{-1}$ . Results show in the west coast stations, nearly 82% of the total rainfall is convective in nature, at the middle of the peninsula 53% of the total rain is convective while in the east coast stations 46% contribution from the convective rain is seen. Kanghwa receives the maximum convective rain while at Ulsan the convective rain is minimum. Correlation coefficient between the total precipitation and CG lightning during the summer monsoon season is 0.54. -
Asian dust aerosol layer of 4-6 km altitude accompanied by low clouds was observed by LIDAR and sky-radiometer in Tokyo urban area on April 10, 2001. To synthesize the top of atmosphere (TOA) reflectance, radiative transfer simulation conducted assuming aerosol/cloud vertical structure and aerosol size distribution that were modeled after the ground observations. The refractive index of Asian dust is derived from a laboratory measurement of sampled Chinese soil particles. The synthesized TOA reflectance is compared to the SeaWiFS-derived one sampled at the low cloud pixels whose airmass is the same as the one passed at the observation site. While the two TOA reflectances compare generally well with few percent difference in reflectance, possible sources of the discrepancy are discussed.
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The Measurement of Pollution in the Troposphere (MOPITT) instrument is an eight-channel gas correlation radiometer launched on the Earth Observing System (EOS) Terra spacecraft in 1999. Its main objectives are to measure carbon monoxide (CO) and methane (CH4) concentrations in the troposphere. This work analyzes tropospheric carbon monoxide distributions using MOPITT data in East Asia and compared ozone distributions. In general, seasonal CO variations are characterized by a spring peak and decreased in the summer. Also, this work revealed that the seasonal cycles of CO are spring maximum and summer minimum with averaged concentrations ranging from 118ppbv to 170ppbv. The CO monthly means show a similar profiles to those of O3. This fact clearly indicates that the high concentration of CO in spring is caused by two possible causes: the photochemical CO production in the troposphere, transport of the CO in the northeast Asia. The CO and O3 seasonal cycles in northeast Asia are influenced extensively by the seasonal exchange of the different types of air mass due to the Asian monsoon. The continental air masses contain high concentrations of O3 and CO due to higher continental background concentrations and sometimes due to the contribution of regional pollution. In summer the transport pattern is reversed. The Pacific marine air masses prevail over Korea, so that the marine air masses bring low concentrations of CO and O3, which tend to give the apparent minimum in summer.
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We retrieved the aerosol optical thickness
$\tau$ $_{a}$ over land from Landsat-7/ETM+ image data using the correlation between the visible reflectance and middle IR reflectance. This band correlation method for aerosol retrieval was originally proposed fur MODIS data analysis by Kaufman et al.(1977). The results of retrieved aerosol optical thickness$\tau$ $_{a}$ from Landsat-7/ETM+ data were compared with the simultaneous sky observation data at our study site. We found a good agreement between the retrieved and observed values. We presented the distribution maps of the aerosol optical thickness over land, retrieved from Landsat-7/ETM+ image data. Then, the surface reflectance map was also presented. The aerosol optical thickness over sea was retrieved assuming no reflected contribution from sea in the near IR band. In addition, we discussed some limitations when we apply the band correlation method. -
In this paper, we propose a geostatistical approach incorporated to the Bayesian data fusion technique for supervised classification of multi-sensor remote sensing data. Traditional spectral based classification cannot account for the spatial information and may result in unrealistic classification results. To obtain accurate spatial/contextual information, the indicator kriging that allows one to estimate the probability of occurrence of classes on the basis of surrounding observations is incorporated into the Bayesian framework. This approach has its merit incorporating both the spectral information and spatial information and improves the confidence level in the final data fusion task. To illustrate the proposed scheme, supervised classification of multi-sensor test remote sensing data set was carried out.
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Remote sensing data is collected and analyzed to enhance understanding of the terrestrial surface. Since Landsat satellite was launched in 1972, many researches using multispectral data has been achieved. Recently, with the availability of airborne and satellite hyperspectral data, the study on hyperspectral data are being increased. It is known that as the number of spectral bands of high-spectral resolution data increases, the ability to detect more detailed cases should also increase, and the classification accuracy should increase as well. In this paper, we classified the hyperspectral and multispectral data and tested the classification accuracy. The MASTER(MODIS/ASTER Airborne Simulator, 50channels, 0.4~13
$\mu$ m) and Landsat TM(7channels) imagery including Yeong-Gwang area were used and we adjusted the classification items in several cases and tested their classification accuracy through statistical comparison. As a result of this study, it is shown that hyperspectral data offer more information than multispectral data. -
In this paper, Multisource data classification methods based on Bayesian formula are considered. For this decision fusion scheme, the individual data sources are handled separately by statistical classification algorithms and then Bayesian fusion method is applied to integrate from the available data sources. This method includes the combination of each expert decisions where the weights of the individual experts represent the reliability of the sources. The reliability measure used in the statistical approach is common to all pixels in previous work. In this experiment, the weight factors have been assigned to have different value for all pixels in order to improve the integrated classification accuracies. Although most implementations of Bayesian classification approaches assume fixed a priori probabilities, we have used adaptive a priori probabilities by iteratively calculating the local a priori probabilities so as to maximize the posteriori probabilities. The effectiveness of the proposed method is at first demonstrated on simulations with artificial and evaluated in terms of real-world data sets. As a result, we have shown that Bayesian statistical fusion scheme performs well on multispectral data classification.
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Recently, the enormous increase in the volume of remotely sensed data is being acquired by an ever-growing number of earth observation satellites. The combining of diversely sourced imagery together is an important requirement in many applications such as data fusion, city modeling and object recognition. Aerial triangulation is a procedure to reconstruct object space from imagery. However, since the different kinds of imagery have their own sensor model, characteristics, and resolution, the previous approach in aerial triangulation (or georeferencing) is performed on a sensor model separately. This study evaluated the advantages of aerial triangulation of large number of images from multi-sensors simultaneously. The incorporated multi-sensors are frame, push broom, and whisky broom cameras. The limits and problems of push-broom or whisky broom sensor models can be compensated by combined triangulation with frame imagery and vise versa. The reconstructed object space from multi-sensor triangulation is more accurate than that from a single model. Experiments conducted in this study show the more accurately reconstructed object space from multi-sensor triangulation.
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The most widespread techniques for DEM generation are stereoscopy for optical sensor images and interfereometry for SAR images. These techniques suffer from certain sensor and processing limitations, which can be overcome by the synergetic use of both sensors and DEMs respectively. In this paper, different strategies for fusing SAR and optical data are combined to derive high quality DEM products. The filtering techniques, which take advantage of the complementary properties of SAR and stereo optical DEMs, will be applied for the fusion process. By taking advantage of the fact that errors of the DEMs are of different nature using the filtering technique, affected part are filtered and replaced by those of the counterpart and is tested with two sets of SPOT and ERS DEM, resulting in a remarkable improvement in DEM. for the analysis of results, the reference DEM is generated from digital base map(1:5000).
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The emergence of viral diseases transmitted is nowadays a central problem in the world. Problem, which is becoming very critical in developing countries, where the health systems are not yet enough developed to face the bursting of such diseases. Emerging viral diseases constitute one of the major threats to human being that are arising in the modern world. Besides bio-chemical and medical researches, new orientations are developed to understand the environmental dimensions of such emergence. Questions concerning the inter-plays between the environmental and disease dynamics are building up new investigations, both in remote sensing and GIS, for the elaboration of levels of organization of space and environment in relation to incidences, to gain understandings in these issues. Environmental attributes attached to land cover types: area, spatial heterogeneity and physical state, are derived from remote sensing and applied to uncover related dimensions of the Dengue disease.
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Kakegawa City is located at 138 deg. E and 34 deg. 45 min. N, in the west of Shizuoka Prefecture. Its population is approximately eighty thousands and its area is 185.79 square kilometers as shown in Fig.1. The city government has been developing GIS for the purpose of land management and tax base calculation and is one of the most advanced local governments in Shizuoka Prefecture. The city government has been developing the database of various kinds of physical and social environmental information, but the city government uses small parts of the database only fur land management and tax base calculation. The purpose of this report is to show the database of kakegawa City as shown in Table 1 and propose the effective usage of the database. The database of Kakegawa City as shown in Fig.2 and Fig.3 is imported to GIS in our laboratory and reconstructed as the database retrievable from each individual land. The authors developed the retrieval system of each individual land and combined it to the reconstructed database. If our GIS is open to the public, a lot of citizens will get useful information about their environments.
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Contrary to the traditional text-based information, 4S(GIS,GNSS,SIIS,ITS) information can contribute to the citizen's welfare in upcoming era. Recently, GSIS(Geo-Spatial Information System) has been applied and stressed out in various fields. As analyzed the data from GSIS arena, the position information of objects and targets is crucial and critical. Therefore, several methods of getting and knowing position are proposed and developed. From this perspective, Position collection and processing are the heart of 4S technology. We develop 4S-Van that enables real-time acquisition of position and attribute information and accurate image data in remote site. In this study, the configuration of 4S-Van equipped with GPS, INS, CCD and eye-safe laser scanner is shown and the merits of DGPS/INS integration approach for geo-referencing is briefly discussed. The algorithm of DGPS/INS integration fur determination of six parameters of motion is eccential in the 4S-Van to avoid or simplify the complicated computation such as photogrammetric triangulation. 4S-Van has the application of Laser-Mobile Mapping System for three-dimensional data acquisition that merges the texture information from CCD camera. The technique is also applied in the fields of virtual reality, car navigation, computer games, planning and management, city transportation, mobile communication, etc.
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The scientific objectives of PACRIM (Pacific Rim) are to advance the understanding of polarimetric and interferometric radar and to promote its application in environmental research designed to detect and quantify changes found in both the physical and humanly dominated ecosystems on the earth's surface. The information derived is used to more readily identify environments at risk; improve environmental decision making and the management of resources and thereby lead to the implementation of more effective and sustainable land use practices. PACRIM is a collaborative research project was organized by NASA's Mission to Planet Earth, Airborne Sciences Program; the Jet Propulsion Laboratory; CSIRO-COSSA and the Centre for Remote Sensing and GIS at the University of New South Wales. A decade of working with AIRSAR data (1993-2003) in the Australia-Asian-Pacific region has provided the opportunity for more than 400 investigators from 20 countries to collect, analyse, interpret and apply state-of-the-art radar data to earth-science studies. This has been achieved by scientists working within seven broad research themes; o Forestry and vegetation o Geology and tectonic processes o Interferometry o Disaster management o Coastal analysis o Agriculture o Urban and regional development. This paper presents an overview of the three data acquisition missions (1993,1996 and 2000) and the science research outcomes achieved from analyzing high quality radar data.
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The Synthetic Aperture Radar (SAR) data are considered to contain the greatest amount of information among various microwave techniques developed for measuring ocean variables from aircraft or satellites. They have the potential of measuring wavelength, wave direction and wave height of the ocean waves. But, it is difficult to retrieve significant ocean wave heights and surface current from conventional SAR data, since the imaging mechanism of ocean waves by a SAR is determined by the three basic modulation processes arise through the tilt modulation, hydrodynamic modulation and velocity bunching which are poorly known functions. Along-Track Interferometric (ATI) SAR systems can directly detect the Doppler shift associated with each pixel of a SAR image and have been used to estimate wave fields and surface currents. However, the Doppler shift is not simply proportional to the component of the mean surface current. It includes also contributions associated with the phase velocity of the Brags waves and orbital motions of all ocean waves that are longer than Brags waves. In this paper, we have developed a new method for extracting the surface current vector using multiple-frequency (L- & C-band) ATI SAR data, and have generated surface wave height information.
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The objective of this study is to analyze the relationship between polarimetric radar backscatters and stand characteristics over the mountainous forest area. L- and P-band full polarimetric airborne SAR data obtained in September 2000 were processed to compare with forest stand maps and ground collected stand variables. After the geometric registration of SAR image, mean radar backscatters were extracted for those ground plots where the stand parameters, such as tree height, DBH, and basal area, were measured during and after the SAR data acquisition. Preliminary analysis was focused on the topographic influence of radar backscattering under the homogeneous forest stand condition. Topographic effects, assessed by the local incidence angles, were different obvious in L-band data while it was not clear with P-band data.
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In order to ensure a balance between economic development and a healthy Mekong Basin environment supporting natural resources diversity and productivity critical to the livelihood of its 65 million inhabitants, the Mekong River Commission (MRC) has been investigating the use of radar to remotely characterize and monitor the diversity, complexity, size and connectivity of the Basin's aquatic habitats. The PACRIM AIRSAR Mission provided an opportunity to evaluate the usefulness of radar technology to derive information for assessing, forecasting and mitigating possible cumulative and long-term impacts of development on the natural environment and the people's livelihood. This paper presents the results of mapping wetland cover types using multi-polarimetric radar for an area of the north-western corner of the Tonle Sap basin with data acquired from the AIRSAR Mission in September 2000. The implementation of a newly developed segmentation classification routine used to derive the image classification is described and the results of a fieldwork campaign to check the classification is presented.
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When a SAR system operates in a full-polarimetic mode, the amount of the information one can extract is so complex that the effective presentation of the information is important. However, the information acquired from the polarimetric SAR data is often difficult to interpret by itself, because it is consisted of both the amplitude information and the phase information. Polarimetric parameters are the good way of representing the polarimetric SAR information in a quantitative manner. Also they can characterize the scattering behavior of the ground scatterer. In this research, extraction of polarimetric parameters, evaluation and interpretation of the scattering behavior of the ground with respect to polarimetric SAR signal are carried out. Using the NASA/JPL AIRSAR data, we estimated the polarimetric parameters and compared them in terms of the ground features. In general, extracted parameters well represent the characteristics of the different features on the ground.
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Remote sensing technology is one of the most powerful tools for human to know the nature and their living environment. However, before microwave remote sensing was developed and applied, remote sensing application was limited strongly by weather and time. Microwave remote sensing technology solves the problem. It makes us to have the capability to acquire information at all time of the day and under all weather condition, and make remote sensing technology be used in more wider area. Microwave remote sensing system include mainly Synthetic Aperture Radar (SAR), Microwave Radiometer, Microwave Scatterometer, and Altimeter (ALT). As SAR can acquire image whose spatial resolution is similar with visible and infrared image, it is paying much attention to and playing a more and more important role in earth observation. In recent year, the development of new SAR technology (multi-band and multi-polarization technology, InSAR technology, D-InSAR technology, and so on) makes SAR remote sensing go to an new stage, and its application area become more and more widely. The first Synthetic Aperture Radar (SAR) in the world appeared in 1960. After that, SAR and its application all developed very fast. Some radar satellites launched and run (include Seasat-A in 1978, ERS-1 in 1991, JERS-1 in 1992, Radarsat in 1995, and so on) promote SAR research and application in world greatly. China began to develop its SAR sensor and research SAR application in 1970s. After more than 30 years' research, it get some important development in sensor development data processing method, and application. Some operational systems have been used and play an important role. This paper will introduce the development of SAR technology and its application in China.
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We have developed a new method to visualize river networks in tropical rain forests from JERS-1 SAR images. This method compresses river information in an original SAR image to a small image displaying wide rivers as dark objects in real size and narrower rivers as bright objects showing brightness level as an indicator of the discharge. We applied this method to 476 images of Amazon forests, 13 observations for path 415 data and 11 observations for path 416 data between 1993 and 1997. We confirmed that a change observed in a preliminary experiment was certainly a part of seasonal changes. The changes roughly correspond to the monthly precipitation changes. Through a simple digital analysis although qualitative, we also detected subtle but consistent regional differences among minor tributaries that belong to a major tributary basin.
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Multitemporal interferometric SAR has became an useful geodetic tool for monitoring Earth's surface deformation, generation of precise DEM, and land cover classification even though there still exist certain constraints such as temporal and spatial decorrelation effects, atmospheric artifacts and inaccurate orbit information. The Korea where nearly all areas are heavily vegetated, JERS-1 SAR has advantages in monitoring surface deformations and environmental changes in that it uses 4-times longer wavelength than ERS-l/2 or RADARSAT SAR system. For generating differential SAR interferogram and differential coherence image fer deformation mapping and temporal change detection, respectively, topographic phase removal process is required utilizing a reference inteferogram or external DEM simulation. Because the SAR antenna baseline parameter for JERS-1 is less accurate than those of ERS-l/2, one can not estimate topographic phases from an external DEM and the residual phase appears in differential interferogram. In this paper, we examined topographic phase retrieval method utilizing an external DEM. The baseline refinement is carried out by minimizing the differences between the measured unwrapped phase and the reference points of the DEM.
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A novel phased array antenna system for space-borne polarimetric SAR is proposed and completed in this paper.The antenna system assures polarimetric and multi-mode capability of SAR. It has broadband, high polarization isolation and high port to port isolation. The antenna system is composed of broadband polarimetric microstrip antenna, T/R modules and multifunction beam controller nit. The polarimetric microstrip antenna has more than 100MHz bandwidth at L-band with -30dB polarization isolation and high port to port isolation. The microstrip element and T/R module's structure and characteristics, the subarray's performances measuring results are presented in detail in this paper. A design scheme on beam controller of the phased array antenna is also proposed and completed, which is based on Digital Signal Processing (DSP) chip -TMS320F206. This beam controller unit has small size and high reliability compared with general beam controller. In addition, the multifunction beam controller unit can acquire and then send the T/R module's working states to detection system in real time.
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To detect ground subsidence, the permanent scatterer SAR interferometry is applied to the Shinho industrial complex. Eleven JERS-1 images were acquired in the study area between October 1996 and September 1998. All SAR data were co-registered to one master scene (January 8, 1998) and thus 10 interferograms were obtained in a time series. In order to determine permanent scatterers, coherence maps as well as the interferograms were generated and exploited. The coherence at the selected PSs was larger than 0.4 in a 515 sub-window and 0.5 in a 39 sub-window. Twenty-nine PSs within the reclaimed land and 8 PSs (as reference phase) outside the plant were selected for the analysis. The 29 PSs were grouped into 5 sub-groups. We removed the reference phase, which was estimated from 8 outside PSs that were considered as phases free of displacement, from the phases at PSs inside the plant. Residual phases could be interpreted as surface displacement and DEM error. The subsidence of about 40 cm was detected at group 4, while surface displacements were negligible in the rest groups.
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In the past 20 years or so, numerous methods to reduce speckle in SAR images have been proposed. The primary goal of these methods is to reduce speckle without destroying resolution and smearing edge information. But the experiments indicate that there is always a kind of tradeoff between smoothing out speckle and preserving edge information. In this paper, an optimal SAR speckle filter is developed. It can effectively smooth out speckle while preserve edge information.
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This paper concerns the design and implementation of a Bandwidth Variable Digital Chirp Generator (DCG) for the radar altimeter. A double SRAM parallel structure is used to breakthrough the upper DCG bandwidth limited by the highest clock frequency of the digital chips. An experimental system working in the waveform storage method has been implemented. We show that the bandwidth changed according to the radar altimeter's requirement and the design released the stringent speed requirement of the chips fur making a variable wide bandwidth DCG.
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The purpose of this report is to show the process of the development of the database of physical and social environments of Iwata City as the basic information for estimation of earthquake disasters and to show the contents of a computer application for handling the database. As the development of GIS in Iwata City, several facts were revealed as the very useful information for the prediction of disasters.
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The goal of this study is to apply and evaluate the precipitation outflow in river basin using satellite data and GIS for proposing the efficient watershed management method. Not only precipitation outflow data but also various spatial data such as digital map, soil map, geologic map and multi-temporal TM images were used. Using landcover classification result and soil map were applied to estimate the average CN. The CN value of 63.37 by SCS method was produced in AMC-2 condition otherwise the result of direct estimation with observation method was 63 CN value. The relative error of two results was 0.59%. It can be possible to apply the satellite data for precipitation outflow analysis. For more accurate and credible analysis of this, the more multi-temporal satellite and real observation data will be needed.
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Based on the real-time monitoring by remote sensing and dynamic management by GIS on agricultural land and water resources in arid area, we solved the practicability and popularization of small-scale spatial information service system. Through demonstration, the standards of spatial information service database of agricultural land and water resources is set up, and the agricultural land and water resources management system in Shehezi City of Xinjiang Autonomy is established, which provides periodically the spatial information services needed by agricultural production to support for sustainable development in arid area.
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S. Korean Government has accelerating its efforts to enhance the quality of the drinking water. The Ministry of Environment has declared the law of securing water-pollutant buffering zone to minimize the inflow of the point and nonpoint sources into the drinking water sources. As a first phase of installing nationa-wide water-pollutant buffering zone, approximately 300km buffering zone has been delineated along the South and North Han river, the major drinking water sources for the capital area of S. Korea, which has the population of more than 12 millions. The buffering zone has the width of 1,000 meter for the special protection area, and 500 meter for the remaining area from both ends of the river. The major works have been done in three stages. Firstly, the boundaries lines of the buffering zone was delineated on the digital topographic maps. Secondly, the maps were overlayed with the cadastral maps to identify individual land parcels, the street address of the major pollutant discharging facilities, and all different types of pollutants including livestocks. Thirdly, the field work has been done as a verification. Once the buffering zone was generated, all the information for the buffering gone were created or imported from other government agencies including official land price, details of the major manufacturing facilities discharging considerable amount of pollutants, major motels and resorts, not to mention of restaurants, etc. Also, major livestock houses were located to identify the path of the pollutant inflow to the drinking water source. Further works need to be continued such as purchasing private lands within the buffering zone and change the land use in the efforts to decrease the pollutant amount and to provide more environmentally friendly space. Also, high resolution satellite imagery should be utilized in the near future as a cost-effective data source to update all the landuse activities within buffering zone.
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Remote Sensing Monitoring and Loss Estimated System of Flood Disaster based on GIS is an integrated system comprised flood disaster information receiving and collection, flood disaster simulation, and flood disaster estimation. When the system receives and collects remote sensing monitoring and conventional investigation information, the distributional features of flood disaster on space and time is obtained by means of image processing and information fusion. The economic loss of flood disaster can be classified into two pus: direct economic loss and indirect economic loss. The estimation of direct economic loss applies macroscopic economic analysis methods, i.e. applying Product (Industry and Agriculture Gross Product or Gross Domestic Product - GDP) or Unit Synthetic Economic Loss Index, direct economic loss can be estimated. Estimating indirect economic loss applies reduction coefficient methods with direct economic loss. The system can real-timely ascertains flood disaster and estimates flood Loss, so that the science basis fur decision-making of flood control and relieving disaster may be provided.
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With the wide usage of LiDAR data and high-resolution satellite image, 3D modeling of buildings in urban areas has become an important research topic in the photogrammetry and computer vision field for many years. However the previous modeling has its limitations of merely texturing the image to the DSM surface of the study area and does not represent the relief of building surfaces. This study is focused on presenting a system of realistic 3D building modeling from consecutive stereo image sequences using digital camera. Generally when acquiring images through camera, various parameters such as zooming, focus, and attitude are necessary to extract accurate results, which in certain cases, some parameters have to be rectified. It is, however, not always possible or practical to precisely estimate or rectify the information of camera positions or attitudes. In this research, we constructed the collinearity condition of stereo images through extracting the distinctive points from stereo image sequence. In addition, we executed image matching with Graph Cut method, which has a very high accuracy. This system successfully performed the realistic modeling of building with a good visual quality. From the study, we concluded that 3D building modeling of city area could be acquired more realistically.
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Recently in the field of telecommunication, there is much interest in geo-surface characteristics of urban areas. Geophysical properties of urban features are now incorporated with accurate positional information to model the telecommunication environment. In this study, three-dimensional buildings are geometrically reconstructed from existing vector maps and aerial images. Accurate digital vector maps are easily available in Korea. However existing maps, which had been produced for GIS applications, do not have height information which is critical to three dimensional building reconstruction. Image matching techniques were applied to aerial image stereopairs to automatically extract the height information of buildings. Planimetric coordinates from vector maps were used as initial guides in the process. Future studies will be undertaken to link geophysical properties to the three-dimensional spatial objects reconstructed from this study thus bringing the telecommunication environment model closer to reality.
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Nowadays the Rational Function Model (RFM), an abstract sensor model, is substituting physical sensor models for highly complicated imaging geometry. But RFM is algorithm to be required many Ground Control Points (GCP). In case of RFM of the third order, At least forty GCP are required far RFM generation. The purpose of this study is to research more efficient algorithm on GCP and accurate algorithm similar to RFM. The Polynomial Camera Model is relatively accurate and requires a little GCP in comparisons of RFM. This paper introduces how to generate Polynomial Camera Model and fundamental algorithms for construction of 3-D topographic data using the Polynomial Camera Model information in the Kompsat stereo pair and describes how to generate the 3-D ground coordinates by manual matching. Finally we tried to extract height information for the whole image area with the stereo matching technique based on the correlation.
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In this paper, we report the development of two DEM (digital elevation model) generation algorithms over urban areas from an IKONOS stereo pair. One ("EpiMatch") is originally developed for SPOT images and modified for IKONOS images. It uses epipolar geometry for accurate DEM generation. The other is based on graph-cut algorithm in 3D voxel space. This algorithm is believed to work better on height discontinuities than EpiMatch. An IKONOS image pair over Taejon city area was used for tests. Using ground control points obtained from differential GPS, camera model was set up and stereo matching applied. As a result, two DEMs over urban areas were produced. Within a DEM from EpiMatch small houses appear as small "cloudy" patches and large apartment and industrial buildings are visually identifiable. Within the DEM from graph-cut we could achieve better height information on building boundaries. The results show that both algorithms can generate DEMs from IKONOS images although more research is required on handling height discontinuities (for "EpiMatch") and on faster computation (for "Graph-cut").
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An approach for quickly updating GIS building data using high resolution remotely sensed data is proposed in this paper. High resolution remotely sensed data could be aerial photographs, satellite images and airborne laser scanning data. Data from different types of sensors are integrated in building extraction. Based on the extracted buildings and the outdated GIS database, the change-detection-template can be automatically created. Then, GIS building data can be fast updated by semiautomatically processing the change-detection-temp late. It is demonstrated that this approach is quick, effective and applicable.
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This paper proposes an approach of automatically calculating the center location of fiducial marks up to sub-pixel accuracy with model-free condition. The conceptual model, composed of two assumptions, about general geometric property of fiducial area and fiducial mark is established. The proposed approach is primarily based on the strategy of calculating the center of symmetry and is composed of three steps of processing: (a) determining horizontal center of fiducial area, (b) locating center of a fiducial mark, and, (c) finally calculating the exact center up to sub-pixel accuracy. Evaluation with respect to RMK style marks and RC style ones shows that the proposed approach can be evaluated as robust one. However there are several images which can't be analyzed by the proposed approach.
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Geometric correction is a critical step to remove geometric distortions in satellite images. For correct geometric correction, Ground Control Points (GCPs) have to be chosen carefully to guarantee the quality of corrected satellite images. In this paper, we present an automatic approach for geometric correction by constructing GCP Chip database (GCP DB) that is a collection of pieces of images with geometric information. The GCP DB is constructed by exploiting Landsat's nadir-viewing property and the constructed GCP DB is combined with a simple block matching algorithm for efficient GCP matching. This approach reduces time and energy for tedious manual geometric correction and promotes usage of Landsat images.
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In this paper, we introduce a more improved camera modeling method for linear pushbroom images than the method proposed by Orun and Natarajan(ON). ON model shows an accuracy of within 1 pixel if more than 10 ground control points(GCPs) are provided. In general, there is high correlation between platform position and attitude parameters but ON model ignores attitude variation in order to overcome such correlation. We propose a new method that obtains an optimal solution set of parameters without ignoring the attitude variation. We first assume that attitude parameters are constant and estimate platform position's. Then we estimate platform attitude parameters using the values of estimated position parameters. As a result, we can set up an accurate camera model for a linear pushbroom satellite scene. In particular, we can apply the camera model to its surrounding scenes because our model provide sufficient information on satellite's position and attitude not only for a single scene but also for a whole imaging segment. We tested on two images: one with a pixel size 6.6m
$\times$ 6.6m acquired from EOC(Electro Optical Camera), and the other with a pixel size 10m$\times$ l0m acquired from SPOT. Our camera model procedures were applied to the images and gave satisfying results. We had obtained the root mean square errors of 0.5 pixel and 0.3 pixel with 25 GCPs and 23 GCPs, respectively. -
The necessity of a short period of software development with lower cost came out. The reason of making the component based development is that it can improve the software development , productivity maintenance , and software quality innovatively. Following these advantages of component based application development methods, we found the COM based components effective to Window platform in the satellite surveying. In this paper, we can obtain many precious engineering experiences. Software system development and maintenance will take much shorter time with higher reusability if satellite surveying system is constructed with component extraction proposed by us.
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Physical sensor model in pushbroom satellite images can be made from sensor modeling by rotation parameters and attitude parameters on the satellite track. These parameters are determined by the information obtained from GPS, INS, or star tracker. Provided from satellite image, an auxiliary data error is connected directly with an error of rotation parameters and attitude parameters. This paper analyzed how obtaining satellite images influenced errors of rotation parameters and attitude parameters. furthermore, for detailed analysis, this paper generated simulated satellite image, which was changed variously by rotation parameters and attitude parameters of satellite sensor model. Simulated satellite image is generated by using high-resolution digital aerial image and DEM (Digital Elevation Model) data. Moreover, this paper determined correlation of rotation parameter and attitude parameters through error analysis of simulated satellite image that was generated by various rotation parameters and attitude parameters.
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This paper describes a new algorithm named as ray following algorithm which is applied for high-resolution satellite image simulation. The problems of the conventional ray tracing algorithm are pointed out especially when terrain elevations vary abruptly. The proposed algorithm follows the directional ray vector sequentially and thoroughly in order to determine the crossing point of the ray with the terrain surface. This way of sequential height comparison method is regarded as the only way to obtain accurate surface cross-section when a highly variant digital surface model is used. The experimental results show and compare the validities of the conventional and proposed algorithms.
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Terra MODIS is one of the few space-borne sensors currently capable of acquiring radiometric data over the range of view angles. Institute of Industrial Science, University of Tokyo, has been receiving Terra MODIS data at Tokyo since May 2001 and Asian Institute of Technology at Bangkok since May 2001. They can cover whole East Asia and is expected to monitor environmental changes regularly such as deforestation, forest fires, floods and typhoon. Over eight hundred scenes have been archived in the storage system and they occupy 2 TB of disk space so far. In this study, MODIS data processing system on WWW is developed including following functions: spectral subset (250m, 500m, 1000m channels), radiometric correction to radiance, spatial subset of geocoded data as a rectangular area with latitude-longitude grid system in HDF format, generation of a quick look file in JPEG format. Users will be notified just after all the process have finished via e-mail. Using this system enables us to process MODIS data on WWW with a few input parameters and download the processed data by FTP access. An easy to use interface is expected to promote the use of MODIS data. This system is available via the Internet on the following URL from September 1 2002, "http : //webmodis.iis.u-tokyo.ac.jp/".
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The Landsat Program is the longest running enterprise for acquisition of imagery of the Earth from space. The first Landsat satellite was launched in 1972 and the most recent, Landsat 7, was launched on April 15, 1999. The Landsat satellites have acquired millions of images. The Landsat 7 receiving station is installed at more than 25 sites and will be installed in Korea. This paper will address the work being carried out for the development of image receiving and processing system for the Landsat 7 image data, which will be used at ground station of Landsat 7 in Korea.
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Thermal infrared imaging is a highly promising technology for condition monitoring and predictive maintenance of electronic, electrical and mechanical elements in nuclear power plants. However, conventional low-cost infrared imaging systems suffer from poor spatial resolution compared to commercial CCD cameras. This paper describes an approach to enhance inspection performances for calandria reactor area of Wolsung nuclear power plant through the technique of superimposing thermal infrared image into real CCD image. In the occurrence of thermal abnormalities on observation points and areas of calandria reactor area, unusual hot image taken from thermal infrared camera is mapped upon real CCD image. The performance of the technique has been evaluated in the experiment carried out at Wolsung nuclear power plant in the overhaul period. The results show that localizations of thermal abnormalities on calandria reactor face can be estimated accurately.
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The development of 2-D radiometer is a new technical challenge for space borne remote sensing area. The Y-type antenna array has been proposed as a most efficient configuration because a large alias free FOV and a small-synthesized beam-width can be achieved compared to L-, T-type under the fixed antenna spacing. New configuration of antenna array, which is called sub-Y type configuration, is proposed to obtain a higher angular resolution than the case of Y-type array in the paper. The sub-Y type array is consisted of basic arrays, which are the Y-type array of four antenna elements. To analyze characteristics of the proposed configuration, the synthesized beam pattern is simulated through simulation. The secondary effect of the sub-Y-type is that the reconstructed image is suffered from the alias effect is appeared around the real target. The ghost targets in the reconstructed image can be reduced by the alias suppression algorithm introduced in this paper. In conclusion, the performance evaluation by use of array factor simulation shows more than 37.5% improvement in average for angular resolution and almost similar performance for temperature resolution.
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A new digital correlator fur an airborne synthetic aperture radiometer was designed in order to replace the conventional analog correlator unit which will become very complicated while the number of channels is increasing. The digital correlator uses digital IQ demodulator instead of the intermediate frequency (IF) phase shifter to make the correlation processing performed digitally at base band instead of analogly at IF. This technique has been applied to the digital receiver in softradio. The down-converted IF signals from each pair of receiver channels become low rate base-band digital signals after under-sampled, Digitally Down-Converted (DDC), decimated and filtered by FIR filters. The digital signals are further processed by two digital multipliers (complex correlation), the products are integrated by the integrators and finally the outputs from the integrators compose of the real part and the imaginary part of a sample of the visibility function. This design is tested by comparing the results from digital correlators and that from analog correlators. They are agreed with each other very well. Due to the fact that the digital correlators are realized with the help of Analog-Digital Converter (ADC) chips and the FPGA technology, the realized volume, mass, power consumption and complexity turned out to be greatly reduced compared with that of the analog correlators. Simulations show that the resolution of ADC has an influence on the synthesized antenna patterns, but this can be neglected if more than 2bit is used.
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Kong, De-Cai;Kim, Yong-Hoon;Li, Jing;Zhang, Sheng-Wei;Sun, Mao-Hua;Liu, He-Guang;Jiang, Jing-Shan 593
The paper introduces a research on the W-band Millimeter Wave Radiometer(RADW92) through an airborne experiment. Microwave remote sensing images of part of the Yellow River and the WeiHe River are of fared. Analysis of factors influencing the image qualities as well as the resolutions to them are also included. The RADW92 is the first generation of Millimeter Wave Radiometer in China, which works with operating frequency 92 GHz, the bandwidth 2 GHz, the integration time 60ms, the system sensitivity 0.6k and the linearity better than 0.999. Cassegrain Antenna is designed for imaging by conically scanning. The result of the experiment suggested that RADW92 had been adequate for space use. -
We summarize the activities concerning to the space-borne microwave radiometer (RAD) calibration and validation (Cal/Val) in China. It is important to know in advance the brightness temperature of a given sea surface before external calibrating RAD due to its special characteristic of system. In the paper, we analyse some modeling results on sea surface emissivity and atmospheric transmissivity at different frequencies, and compare the calculated brightness temperatures with those measurements from some air-borne microwave radiometers. We also introduced the whole contents on RAD Val and developed two methods of retrieving sea surface winds. We compared the retrievals of wind speeds to those from NDBC buoys. At last, we introduce some plans of Cal/Val for testing our RAD.
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Park, Hyuk;Katkovnik, Vladimir;Kang, Gum-Sil;Kim, Sung-Hyun;Choi, Jun-Ho;Choi, Seh-Wan;Jiang, Jing-Shan;Kim, Yong-Hoon 604
The passive microwave remote sensing has progressed considerably in recent years. Important earth surface parameters are detected and monitored by airborne and space born radiometers. However the spatial resolution of real aperture measurements is constrained by the antenna aperture size available on orbiting platforms and on the ground. The inverse problem technique is researched in order to improve the spatial resolution of microwave scanning radiometer. We solve a two-dimensional (surface) temperature-imaging problem with a major intention to develop high-resolution methods. In this paper, the scenario for estimation of both radiometer point spread function (PSF) and target configuration is explained. The PSF of the radiometer is assumed to be unknown and estimated from the observations. The configuration and brightness temperature of targets are also estimated. To do this, we deal with the parametric modeling of observation scenario. The performance of developed algorithms is illustrated on two-dimensional experimental data obtained by the water vapor radiometer. -
Time-mean and absolute geostrophic velocities of the Kuroshio current south of Japan are derived from TOPEX/Poseidon altimeter data using a Gaussian jet model. When compared with simultaneous measurements from a shipboard acoustic Doppler current profiler (ADCP) at two intersection points, the altimetric and ADCP absolute velocities correlate well with the correlation of 0.55 to 0.74. The time-mean velocity is accurate to 1 cm s
$^{-1}$ to 5 cm s$^{-1}$ . The errors in the absolute and the mean velocities are similar to those reported previously far other currents. The comparable performance suggests the Gaussian jet model is a promising methodology for determining absolute geostrophic velocities, noting that in this region the Kuroshio does not meander sufficiently, which provides unfavorable environment for the performance of the Gaussian jet model. -
Probability distribution of the sea surface slope is estimated using sun glitter images derived from visible radiometer on Geostationary Meteorological Satellite (GMS) and surface vector winds observed by spaceborne scatterometers. The brightness of the visible images is converted to the probability of wave surfaces which reflect the sunlight toward GMS in grids of 0.25 deg
$\times$ 0.25 deg. Slope and azimuth angle required for the reflection of the sun's ray toward GMS are calculated for each grid from the geometry of GMS observation and location of the sun. The GMS images are then collocated with surface wind data observed by three scatterometers. Using the collocated data set of about 30 million points obtained in a period of 4 years from 1995 to 1999, probability distribution function of the surface slope is estimated as a function of wind speed and azimuth angle relative to the wind direction. Results are compared with those of Cox and Munk (1954a, b). Surface slope estimated by the present method shows narrower distribution and much less directivity relative to the wind direction than that reported by Cox and Munk. It is expected that their data were obtained under conditions of growing wind waves. In general, wind waves are not always developing, and slope distribution might differ from the results of Cox and Munk. Most of our data are obtained in the subtropical seas under clear-sky conditions. This difference of the conditions may be the reason for the difference of slope distribution. -
A satellite scatterometer is a microwave radar sensor used to measure the backscattering at a sea surface. This instrument transmits radar pulses to the sea surface and measure the radar energy reflected back towards the source. Changes in wind velocity make sea surface roughness change and then affect on backscattered power. This gives us information of sea surface wind speed. Directions of wind vectors are acquired by multiple, collocated, and nearly simultaneous measurements. It should be noted that the scatterometer observes not the wind directly but the wind stress vector relative to the surface current. This suggests the possibility that the satellite scatterometer winds can include the effect of the surface current. This study shows the evidence that scatterometer measure surface wind stress, not surface winds and presents the velocity structure of oceanic warm and cold eddies.
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One main purpose of environmental monitoring after oil spill is developing ESI (Environmental Sensitivity) Maps. Environmental impacts caused by the spilt oil are strongly depending upon the coastal topology and geology. Monitoring all impacted shorelines is almost impossible; using high-resolution satellite images such as IKONOS greatly contributes to improve the efficiency of on-site researches, at the same time, reliability of ESI maps.
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We investigated the distributions of sea ice using various microwave remote sensing techniques in the part of Drake passage, Antarctica, between the area 45-75
$^{\circ}$ W and 55-66$^{\circ}$ S. We used Topex/Poseidon(T/P) radar altimeter, ERS-1 altimeter, ERS-2 scatterometer, Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR), and DMSP Special Sensor Microwave/Imager(SSM/I) data. The sea ice distributions were estimated between May and Jun., 1995 and Oct. and Nov., 1998. The two altimeter measurements (T/P and ERS-1) showed good coherence with the results from the radiometer data in the given period when the ice concentration of 20% and greater was selected. The scatterometer data also showed good correlation with altimetry-implied sea ice surface. The maximum and minimum values of sea ice distribution were appeared in Aug. and Feb., respectively. In general, the sea ice distributions estimated from radar altimeter, radioneter, and scatterometer are well correlated. -
In order to contribute to trial of the ocean weather forecasts, we have developed new generation sea surface temperature. It is clod free, high-spatial resolution daily SST product, which enables us to follow the movements of SST patterns relating to the oceanic variations. The product is produced through an objective analysis merging various infrared and microwave SST products.
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MODIS (MODerate-resolution Imaging Spectroradiometer) onboard the first Earth Observing System (EOS) satellite, Terra, was launched successfully at the end of 1999. The direct broadcast MODIS data has been received and utilized in Korea Meteorological Administration (KMA) since february 2001. This study introduces utilizations of this data, especially for the derivation of sea surface temperature (SST). To produce the MODIS SST operationally, we used a simple cloud mask algorithm and MCSST algorithm. By using a simple cloud mask algorithm and by assumption of NOAA daily SST as a true SST, a new set of MCSST coefficients was derived. And we tried to analyze the current NASA's PFSST and new MCSST algorithms by using the collocated buoy observation data. Although the number of collocated data was limited, both algorithms are highly correlated with the buoy SST, but somewhat bigger bias and RMS difference than we expected. And PFSST uniformly underestimated the SST. Through more analyzing the archived and future-received data, we plan to derive better MCSST coefficients and apply to MODIS data of Aqua that is the second EOS satellite. To use the MODIS standard cloud mask algorithm to get better SST coefficients is going to be prepared.
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Though it was difficult of globally monitor latent heat flux aver the ocean for many years, the situation is rapidly changing by the use of satellite data. Since a bulk formula is used to estimate turbulent heat flux using satellite data, we need wind speed, sea surface temperature and specific humidity data. However, it is not easy to accurately estimate specific humidity using satellite data. Now several algorithms for estimating specific humidity have been proposed and applied to construct latent heat flux data sets. Latent heat flux data sets derived from satellite data such as J-OFURO, HOAPS and GSSTF are available at present. Since the algorithm and used satellite data are not the same between them. the characteristics of each data set may be different. Therefore, it is important to clarify the difference between each data set and investigate the cause of the difference in latent heat flux estimates. In this paper we summarize the present state of the art with regard to the turbulent heat flux estimation by using satellite data. Also we present the comparison results of latent heat flux fields including not only satellite-derived flux fields but also analysis fields.
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In summer season of 1998, a huge flood occurred around the Yangtze River in the eastern China. The low salinity water less than 28 psu from the river was detected around the southeastern part of the Jeju Island which is located in the southern part of the Korean peninsula. We studied how to detect low salinity water from the Yangtze River, which gives terrible damages to the Korean fisheries. We got the relationships between low surface salinity, turbid water from the Yangtze River and digital ocean color using remote sensing of SeaWiFS satellite in the northern East China Sea in summer seanson of 1998, 1999, 2000 and 2001. The charts of salinity in the northern East China Sea were made by the regenerating of the satellite ocean color data with the formula from the relationships between low salinity, in situ turbid water (transparency) and satellite ocean color.
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Spatial distribution of phytoplankton pigment concentration (PPC) and sea surface temperature (SST) around the East Korean Warm Current (EKWC) was described, using both ocean color images and advanced very high resolution radiometer (AVHRR) images. Water mass in this region can be classified into five categories in the horizontal profile of PPC and SST, nLw(normalized water-leaving radiance) images: (1) coastal cold water region associated with concentrations of dissolved organic material or yellow colored substances and suspended sediments, (2) cold water region of thermal frontal occurred by a combination of phytoplankton absorption and suspended materials, (3) warm water overlay region by the phytoplankton absorption than the suspended materials; (4) warm water region occurred by the low phytoplankton absorption, and (5) offshore region occurred by the high phytoplankton absorption. In particular, the highest PPC area appeared in the ocean color and SST images with a band shaped distribution of the thermal front and ocean color front region, which is located the coastal cold waters along western thermal front of the warm streamer of the EKWC.
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It is studied on the relationship between the occurrence of red tide(Chlorophyll-a concentration by the in-situ and satellite data) and the meteorological factors (precipitation, air temperature, sunshine and winds) in the coastal areas in the South Sea of Korea. In summer and early-fall which frequently occurred the red tide, the precipitation above 213mm had directly influence on the occurrence of red tide because it carried the nutritive substance which originated from the land into the coastal areas. Then air temperature kept up generally high values as 23~26
$^{\circ}C$ , and sunshine with 187~198hours and wind velocity with 3.1~7.9m/s showed not directly the relationship on the occurrence of red tide. -
Sea surface temperatures (SSTs) estimated from satellite data are affected by various kinds of disturbance factors. In order to accurately estimate SSTs based on radiometric data observed by satellite, it is important to correct the effects by these disturbance factors. We obtained a huge data set of skin sea surface temperature images observed by a thermal infrared camera (TIC) in MUBEX Campaign. TIC installed on an observation vessel recorded sea surface skin temperature distribution under various weather conditions. Based on some special images observed by TIC, we estimated skin effects and effective sea surface emissivity. In this paper, we report the methods and results of these estimations.
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The National Oceanographic Research Institute of KOREA started to survey for the basic data necessary to territorial sea and EEZ identification and marine development with Multi-Beam Echo Sounder(L3 SeaBeam 2112) since 1996. The Multi-Beam surveys has provided a very new and precise way of describing the morphology and nature of the underwater seabed. Multi-Beam Echo Sounder systems employ sound waves propagating at angles which vary from vertical to nearly horizontal. The locations on the bottom where echoes are generated cover a swath whose port to starboard width may be equal to many times the water depth. Newer Multi-beam bathymetric sonars provide both a beam by beam depth and backscatter amplitude of the bottom. But The backscattered amplitude didn't use for identification of bottom properties because backscatter amplitude effects by the many environmental variables of underwater and seabed. We investigates the utilization of geo-referenced backscatter amplitude and analysis of relationship between The Backscattered Amplitude and Sidescan Sonar imagery from Sea Beam 2112. For the backscattered amplitude imagery mainly represents the properties of sediment, we computed the beam geometry, time-varied amplifier gain, and mainly incidence angle to the topography using bathymetric model at each ping. In this paper, those issues are illustrated, and the angular independent imagery based on swath topographic model is described.
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Intertidal zone (tidal flat) is a place which is sometimes dry and sometimes wet depending on the tidal rhythm. Direct measurement of topography in the intertidal zone is very difficult to be achieved. The interface between wet and dry parts in the tidal flat, which can be identified from near infrared band of satellite image, is a 'depth contour' which corresponds to the sea level at the time of satellite pass. Aquisition of topography data in tidal flat is possible by combining various techniques such as (1) identification of the interface between wet and dry parts, (2) GCP correction of satellite image, and (3) realtime prediction of sea level elevation at the time of satellite pass. The algorithm was successfully applied in obtaining topography (bathymetry) data in the intertidal zone of Asan Bay in the west coast of Korea from 26 satellite images. The method is expected to be very efficient in making bathymetry data base in the western and southern parts of Korea where tidal flats are well developed in wide regions.
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A satellite remote sensing is useful for vegetation monitoring. But it has some problem. One of these, it is difficult to find a difference of vegetation surface roughness using satellite remote sensing. Each vegetation type has unique surface roughness, for example needle leaves forest, broad leaves forest and grassland. Difference of vegetation surface roughness can be detected by satellite multiangular observation. In this study, objective is to propose index of vegetation surface roughness using BRF property. General vegetation indices are calculated from nadir data of satellite data. A proposed index is calculated from two different observation zenith angle data. Two different zenith data can provide BRF (Bi-directional Reflectance Factor) property of satellite observation data. A proposed index was able to detect different value on where NDVI shows similar high value areas of rice field and forest. This index is useful for vegetation monitoring.
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MODIS LAI has been one of key products for analyzing the quantitative aspects ofterrestrial ecology. This study was designed to validate MODIS LAS product by using the reference LAI map that was derived from both ground measurements and ETM+ surface reflectance. The study area, the Kwangneung Experiment Forest in Korea, covers mixed species of deciduous and conifers of temperate forest. Throughout the growing season of 2002, we have measured LAS at the 30 sample plots using an optical device. Ground measured LAS data were then correlated to the ETM+ reflectance to produce a continuous map of LAS over the study area. Preliminary comparison between MODIS LAI and the reference LAI map showed the lower LAI values from the MODIS product.
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This study focused the relationship between the Normalized Difference Vegetation Index (NDVI) and the evapotranspiration (ET) temporal changes. Especially, the interannual change of the NDVI and ET from 1982 to 2000 at regional to continental scales was highlighted mainly over Asia. Monthly global NDVI data were acquired from Pathfinder AVHRR Land (PAL) data (1
$\times$ 1 degree resolution). The monthly ET was estimated from assimilated atmospheric data provided from National Centers for Environmental Prediction (NCEP) (2.5$\times$ 2.5 degree resolution), and gridded global precipitation data of CPC Merged Analysis of Precipitation (CMAP) (2.5$\times$ 2.5 degree resolution). Significant positive correlations were found between the NDVI and ET interannual changes in May and June over western Siberia. Moreover, it was revealed that the most of area in Asia has positive correlation coefficient in May and June. These results delineate that the vegetation activity significantly contributes to the ET interannual change over extensive areas. -
In this forest fire experiment the ThermoViewer was set up on the platform built on a tree and observed the temperature change, before, during and after the fire. The fire experiment had been carried out not only the day of the forest fire experiment but also continued for four months after the forest fire had been gone. The results from the experiment showed that the temperature difference is significant in the afternoon; therefore, afternoon satellite passing is better and suitable time for active forest fires and burnt scars detection; moreover, after 83 days, the burnt and un-burnt vegetation become almost the same condition, fully regenerated and the temperature difference become nearly 0
$^{\circ}$ Celsius, so there is not enough temperature different between burnt and un-burnt vegetation for current sensors to distinguish the difference anymore. -
This paper describes some results of change detection in Tokyo metropolitan area, Japan , using the Landsat TM data, and methods to quantify the ground cover classes. The changes are analyzed using the measures of not only conventional spectral classes but also a set of landscape indices to describe spatial properties of ground cove types using fractal dimension of objects, entropy in the specific windows defining the neighbors of focusing locations. In order eliminate the seasonal radiometric effects on TM data, an automated class labeling method is also attempted. Urban areas are also delineated automatically by defining the boundaries of the urban area. These procedures for urban change detection were implemented by the unified image computing methods proposed by the author, they can be automated in coherent and systematic ways, and it is anticipated to automate the whole procedures. The results of this analysis suggest that Tokyo metropolitan area was extended to the suburban areas along the new transportation networks and the high density area of Tokyo were also very much extended during the period between 1985 and 1995.
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Three periods of land-use maps of the Suomo Basin were drawn from topographic maps (1970a) and Landsat TM/ETM images (1986a and 1999a). The area of each kind of land use was calculated from the three maps. From 1970 to 1999, the area of forestland decreased 17%, the area of sparse forestland increased 8%, and the area of grassland increased 10%. The transferring trend of the land-use is that forestland turned into sparse forestland and brush land, and the brush land degenerated into grassland based on the transferring matrixes from 1970 to 1986, and from 1986 to 1999. According to the local government record and statistical data, forest cover rate had been increasing from 1970 to 1998, but the amount of growing stock had been declining. From 1957 to 1998, the amount of growing stock declined from 423m
$^3$ /ha to 177m$^3$ /ha. -
Recent developments in sensor technologies have provided remotely sensed data with very high spatial resolution. In order to fully utilize the potential of high resolution images, new image classification strategies are necessary. Unfortunately, the high resolution images increase the spectral within-field variability, and the classification accuracy of traditional methods based on pixel-based classification algorithms such as Maximum-Likelihood method may be decreased (Schiewe 2001). Recent development in Object Oriented Classification based on image segmentation algorithms can be used for the classification of forest patches on rugged terrain of Korea. The objectives of this paper are as follows. First, to compare the pros and cons of image classification methods based on pixel-based and object oriented classification algorithm for the forest patch classification. Landsat ETM+ data and IKONOS data will be used for the classification. Second, to investigate ways to increase classification accuracy of forest patches. Supplemental data such as DTM and Forest Type Map of 1:25,000 scale are used for topographic correction and image segmentation. Third, to propose the best classification strategy for forest patch classification in terms of accuracy and data requirement. The research site for this paper is Namhansansung Provincial Park located at the eastern suburb of Seoul Metropolitan City for its diverse forest patch types and data availability. Both Landsat ETM+ and IKONOS data are used for the classification. Preliminary results can be summarized as follows. First, topographic correction of reflectance is essential for the classification of forest patches on rugged terrain. Second, object oriented classification of IKONOS data enables higher classification accuracy compared to Landsat ETM+ and pixel-based classification. Third, multi-stage segmentation is very useful to investigate landscape ecological aspect of forest communities of Korea.
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This paper discussed and analyzed results of different classification algorithms for land use classification in arid and semiarid areas using CBERS-1 image, which in case of our study is Shihezi Municipality, Xinjiang Province. Three types of classifiers are included in our experiment, including the Maximum Likelihood classifier, BP neural network classifier and Fuzzy-ARTMAP neural network classifier. The classification results showed that the classification accuracy of Fuzzy-ARTMAP was the best among three classifiers, increased by 10.69% and 6.84% than Maximum likelihood and BP neural network, respectively. Meanwhile, the result also confirmed the practicability of CBERS-1 image in land use survey.
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There are many global/continental or large area land cover mapping projects because land cover is one of key parameters in environmental studies. Though ground truth collection is a important and difficult task in land cover mapping, it is usually performed independently in each project without any cooperation between them. This is the background of the development of Global Land Cover Ground Truth (GLCGT) database by the cooperation of many projects and researchers. The developed GLCGT database will be used freely by any researcher. This cooperative and common development of GLCGT database will realize reliable and continuously improved land cover ground truth data. It also eliminates duplicated efforts of ground truth collection among projects.
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Precipitation evapotranspiration and runoff are three key parameters of regional water balance. Problems exist in the traditional methods for calculating such factors , such as explaining of the geographic rationality of spatial interpolating methods and lacking of enough observation stations in many important area for bad natural conditions. With the development of modern spatial info-techniques, new efficient shifts arose for traditional studies. Guided by theories on energy flow and materials exchange within Soil-Atmosphere-Plant Continuant (SPAC), retrieval models of key hydrological parameters were established in the Yellow River basin using CMS-5 and FengYun-2 meteorological satellite data. Precipitation and evapotranspiration were then estimated: (1) Estimating tile amount of solar energy that is absorbed by the ground with surface reflectivity, which is measured in the visible wavelength band (VIS): (2) Assessing the partitioning of the absorbed energy between sensible and latent heat with the surface temperature, which was measured in the thermal infrared band (TIR), the latent heat representing the evapotranspiration of water; (3) Clouds are identified and cloud top levels are classified using both VIS and TIR data. Hereafter precipitation will be calculated pixel by pixel with retrieval model. Daily results are first obtained, which are then processed to decade, monthly and yearly products. Precipitation model has been has been and tested with ground truth data; meanwhile, the evapotranspiration result has been verified with Large Aperture Scintillometry (LAS) presented by Wageningen University of the Netherlands. Further studies may concentrate on the application of models, i.e., establish a hydrological model of the Yellow river basin to make the accurate estimation of river volume and even monitor the whole hydrological progress.
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The measurement of river discharge is among the most fundamental observations and is necessary for understanding many water-related issues, such as flooding hazards, sediment transportation, and nutrient movement. Traditionally river discharge is estimated by measuring the water stage and converting the measurement to discharge using a stage-discharge rating curve. The possibility of monitoring river discharge from satellites has been largely ignored, because it is difficult to measure water surface information from space with sufficient precision. In this paper, an efficient approach to discharge estimation using mainly satellite data is developed and described. The proposed method, which focuses on the measurement of water-surface width coupled with river width-stage and stage-discharge relationships, is applied to the Yangtze River with good results.
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We present spectral characteristics of tidal flat sediments and algal mat that were tested in the Gomso and Saemangum tidal flats, Korea. The objective of this study is to investigate the spectral reflectance and the radar scattering modeling in the tidal flats. Ground truth data obtained in the tidal flats include grain size, soil moisture content and its variation with time, surface roughness, chlorophyll, ground leveling, and field spectral reflectance measurement. The concept of an effective exposed area (EEA) is introduced to accommodate the effect of remnant surface water, and it seriously affects the reflection of short wavelength infrared and microwave. The nin size of 0.0625 mm has been normally used as a critical size of mud and sand discrimination. But we propose here that 0.25 mm is more practical grain size criterion to discriminate by remote sensing. Algal mat is the primary product in tidal flats, and it is found to be very important to understand spectral characteristics for tidal flat remote sensing. We have also conducted radar scattering modeling, and showed L-band HV-polarization would be the most effective combination.
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Recently we have discovered that sediments should be separated from lithosphere, and soil should be separated from biosphere, both sediment and soil will be mixed sediments-soil-sphere (Seso-sphere), which is using particulate mechanics to be solved. Erosion and sediment both are moving by particulate matter with water or wind. But ancient sediments will be erosion same to soil. Nowadays, real soil has already reduced much more. Many places have only remained sediments that have ploughed artificial farming layer. Thus it means sediments-soil-sphere. This paper discusses sediments-soil-sphere erosion modeling. In fact sediments-soil-sphere erosion is including water erosion, wind erosion, melt-water erosion, gravitational water erosion, and mixed erosion. We have established geographical remote sensing information modeling (RSIM) for different erosion that was using remote sensing digital images with geographical ground truth water stations and meteorological observatories data by remote sensing digital images processing and geographical information system (GIS). All of those RSIM will be a geographical multidimensional gray non-linear equation using mathematics equation (non-dimension analysis) and mathematics statistics. The mixed erosion equation is more complex that is a geographical polynomial gray non-linear equation that must use time-space fuzzy condition equations to be solved. RSIM is digital image modeling that has separated physical factors and geographical parameters. There are a lot of geographical analogous criterions that are non-dimensional factor groups. The geographical RSIM could be automatic to change them analogous criterions to be fixed difference scale maps. For example, if smaller scale maps (1:1000 000) that then will be one or two analogous criterions and if larger scale map (1:10 000) that then will be four or five analogous criterions. And the geographical parameters that are including coefficient and indexes will change too with images. The geographical RSIM has higher precision more than mathematics modeling even mathematical equation or mathematical statistics modeling.
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Both geophysical and geospatial data provide important information in the establishment of the optimal telecommunication systems especially in the mobile telecommunication environment. The objective of this study is to utilize geophysical properties and geospatial information in the analysis of the telecommunication environment through point-to-point wave property modeling. Geophysical properties associated with wave propagation parameters of the earth surface were analyzed based on hierarchical land classification using Landsat ETM+ and IKONOS images. Three-dimensional geospatial information was obtained by processing stereo aerial images. The results show that the accurate geospatial information and reliable geosphysical property of the surface improve the prediction of receiving power of the receivers located near corners of the buildings where diffractions occur. The wave property model developed from accurate telecommunication environment could be applied to optimal cell planning and delay time analysis.
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This paper is introducing a radio control helicopter as a new platform of ground truth measurement. This helicopter is normally used for spraying an agricultural chemical. It can do pinpoint hovering and programing flight using DGPS etc., A spectrometer with dual port can measure ground surface and white reference plate at the same time. And it can also take digital images by digital camera. It is needed to collect ground reflectance information as satellite sensor footprint size for satellite data validation. Generally it is possible to get such ground reflectance by an airplane measurement. But it is high cost and not so easy to make a measurement by airplane. Developed validation system can provide such ground reflectance in low cost and easy.
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The Airship PKNU is a roughly 12 m (32 ft) long blimp, filled with helium, whose two-gasoline power(3hp per engine) are independently radio controlled. The motors and propellers can be tilted and are attached to the gondola through an axle and supporting braces. Four stabilizing fins are mounted at the tail of the airship. To fill in the helium, a valve is placed at the bottom of the hull. The inaugural flight was on jul. 31.2002 at the Pusan, S.korea Most environment monitoring system\ problem use satellite image. But, Low resolution satellite image (multi-spectral) : 1km ∼ 250 m ground resolutions is lows. So, detail information acquisition is hard at the complex terrain. High resolution satellite image (black and white) 30m : The ground resolution is high. But it is high price, visit cycle and delivery time is long So. We want make high accuracy airship photogrammetry system. This airship can catch picture Multi. spectral Aerial photographing (visible, Near infrared and thermal infrared), and High resolution (over 6million pixel). It can take atmosphere datum (Temperature (wet bulb, dew point, general), Pressure (static, dynamic), Humidity, wind speed). this airship is very Quickness that aircraft install time is lower than 30 minutes, it is compact and that conveyance is easy. High-capacity save image (628 cut per 1time (over 6million and 4band(R,G,B,NIR)) and this airship can save datum this High accuracy navigatin (position and rotate angle) by DGPS tech. and Gyro system. this airship will do monitor about red-tide, sea surface temperate, and CH-A, SS and etc.
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Since the operation of the first satellite-based navigation services, satellite positioning has played an increasing role in both surveying and navigation, and has become an indispensable tool for precise relative positioning. However, in some situations, e.g. at a low angle of elevation, the use of satellites for navigation is seriously restricted because obstacles like buildings and mountains can block signals. As a mean to resolve this problem, the quasi-zenith satellite system has been proposed as a next-generation satellite navigation system. Quasi-zenith satellite is a system which simultaneously deploys several satellites in a quasi-zenith geostationary orbit so that one of the satellites always stay close to the zenith if viewed from a specific point on the ground of East Asia. Thus, if a position measurement function compatible with GPS is installed in the quasi-zenith and stationary satellites, and these satellites are utilized together with the GPS, four satellites can be accessed simultaneously nearly all day long and a substantial improvement in position measurement, especially in metropolitan areas, can be achieved. The purpose of this paper is to evaluate the effectiveness of quasi-zenith satellite system on positioning accuracy improvement through simulation by using precise orbital information of the satellites and a three-Dimensional digital map. Through this simulation system, it is possible to calculate the number of simultaneously visible satellites and available area of the positioning without the need of actual observation.
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This paper analyzes three theories for land degradation assessment and internationl/domestic methods for land degradation monitoring and assessment. Under the guidance of absolute degradation thought, this paper proposes the technological framework for monitoring and appraising cultivated land degradation based on the 3S technique. We can apply 3S technique and analyze the nature, the environmental, the social, and the economic elements which influence the land utilization and degradation synthetically, to set up the indicator system of the cultivated land degradation monitoring and assessment based on 3S technique; to propose the degradation information extraction methods based on 3S technique; to create the quantitative assessment model and method for land degradation; to analyze the ecological environment response of land use and degradation quantitatively; and to propose the measure, policy and suggestion for solving the land degradation problem from the point of view of land utilization.
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Automatic change detection based on the vector-to-raster comparison is hard especially in high-resolution image. This paper proposes a method to designate roads in high-resolution image in sequential manner using the information from vector map in which Hough transform is used for reliability. By its linearity, the road of urban areas in a vector map can be easily parameterized. Following some pre-processing to remove undesirable objects, we obtain the edge map of raster image. Then the edge map is transformed to a parameter space to find the selected road from vector map. The comparison is done in the parameter space to find the best matching. The set of parameters of a road from vector map is treated as the constraints to do matching. After designating the road, we may overlay it on the raster image for precise monitoring. The results can be used for detection of changes in road object in a semi-automatic fashion.
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Currently, high-resolution satellite imagery such as KOMPSAT and IKONOS has been tentatively utilized to various types of urban engineering problems such as transportation planning, site planning, and utility management. This approach aims at software development and followed applications of remotely sensed imagery to transportation geographic analysis. At first, GDPA (Gradient Direction Profile Algorithm) and main modules in it are overviewed, and newly implemented results under MS visual programming environment are presented with main user interface, input imagery processing, and internal processing steps. Using this software, road network are automatically generated. Furthermore, this road network is used to transportation geographic analysis such as gamma index and road pattern estimation. While, this result, being produced to do-facto format of ESRI-shapefile, is used to several types of road layers to urban/transportation planning problems. In this study, road network using KOMPSAT EOC imagery and IKONOS imagery are directly compared to multiple road layers with NGI digital map with geo-coordinates, as ground truth; furthermore, accuracy evaluation is also carried out through method of computation of commission and omission error at some target area. Conclusively, the results processed in this study is thought to be one of useful cases for further researches and local government application regarding transportation geographic analysis using remotely sensed data sets.
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As the KOMPSAT-1 satellite can roll tilt up to
$\pm$ 45$^{\circ}$ , we have analyzed some EOC images taken at different tilt angles fur this study. The required ground coordinates for bundle adjustment and geometric accuracy, are read from the digital map produced by the National Geography Institution, at a scale of 1:5, 000. These are the steps taken for the tilting angle of KOMPSAT-1 satellite to be present in the evaluation of the accuracy of the geometric of each different stereo image data: Firstly, as the tilting angle is different in each image, the satellite dynamic characteristic must be determined by the sensor modeling. Then the best sensor modeling equation is determined. The result of this research, the difference between the RMSE values of individual stereo images is due more the quality of image and ground coordinates than to the tilt angle. The bundle adjustment using three KOMPSAT-1 stereo pairs, first degree of polynomials for modeling the satellite position were sufficient. -
Mapping systems using Satellite Imagery has not been well-established compare to conventional Arial Photograph mapping systems. In order for satellite imagery to produce a stable quality of maps, it requires to follow the standard mapping procedures. In this satellite imagery study, we proposed four methods of mapping procedures. Mapping methods were established by generating trial maps and analyzing types of input data and functions of DPW (Digital Photogrammetric Workstation). On quantitative aspect, accuracy of each steps were measured by increasing 2 GCPs each time from the minimum of 6 GCPs. In DLT, with the minimum of 10 points, RMSE is 2 pixels at most. Besides that, interpretation and stereoscopic plotting using KOMPSAT-1 imagery and other simulated imagery was performed. The tests resulted that, for KOMPSAT-1 (6.6m) stereoscopic images, the possibility of interpretation is 44.79% and possibility of stereoscopic plotting is 43.75%. In the other hand, for simulated imagery (1m), the possibility of interpretation is 60.92% and possibility of stereoscopic plotting is 55.18%.
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In the following paper two algorithms, suitable for the analysis of panchromatic data as provided by KOMPSAT-1 will be presented. One is a texture analysis which will be used to create a settlement mask based on the variations of gray values. The other is a fusion algorithm which allows the combination of high resolution panchromatic data with medium resolution multispectral data. The procedure developed for this purpose uses the spatial information present in the high resolution image to spatially enhance the low resolution image, while keeping the distortion of the multispectral information to a minimum. This makes it possible to use the fusion results for standard multispecatral classification routines. The procedures presented here can be automated to large extent, making them suitable for a standard processing routine of satellite data.
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KOREA-AUSTRIA-AN EXAMPLE OF A CO-OPERATION BETWEEN DATA PROVIDER AND DATA USER ACROSS THE CONTINENTSData provider and data user are linked together by suitable data. This implies that for a successful relationship the provider knows what kind of data, whether original or processed, is needed by the user and that the user articulates his needs to the provider. The co-operation between Korea and Austria aims at identifying these needs and to provide suitable routines for the processing of satellite data. Partners of this co-operation are the Korea Aerospace Research Institute, ARC Seibersdorf research and GeoVille. While the focus of the former lies in the development and running of satellite systems, the latter two have experience in the development and set up of applications in the field of remote sensing. Based on the complementary know-how by the institutions involved, projects were set up in Korea and Austria to fulfill this need and establish a pilot data feed for governmental applications.
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Several environmental problems have occurred and extremely affected throughout the East Asia region. Satellite imageries and spatial information have been used in the applications of environmental and natural hazard management for years. Sharing these data and resources in the community is considered as one of the optimal solution. It would consequently bring cost saving to all participated countries and eventually be beneficial to mankind as a whole. Encouraged by these factors, ASEAN+3 Satellite Image Archive for Environmental Study project was submitted by Thailand in the 3rd Senior Official Meeting between ASEAN, China, Japan and Korea (SEOM+3 Meeting) and approved by the SEOM+3. The main objectives of this project are to share satellite images, information related to natural resources and environmental issues, and to provide data information services to all ASEAN+3 countries. The proposed system is basically embedded by distributed system. The network of data users, data providers, and the center will be established using the Internet. User can access, navigate, display, and even download some archived contents. Its service site can be generally categorized into two parts, which are environmental related data archive and the Integrated satellite image catalogue. The extension of web based GIS is also planned for future development so that GIS users can conduct some preliminary analysis directly on line. This presentation will indicate scope of work, system, working scenario, and work plan of the project.
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Kim, Moon-Gyu;Kim, Tae-Jung;Park, Sung-Og;Im, Yong-Jo;Shin, Ji-Hyun;Choi, Myung-Jin;Park, Seung-Ran;Lee, Jong-Ju 804
Remote sensing division of satellite technology research center (SaTReC), Korea advanced institute of science and technology (KAIST) has developed a ground receiving and processing system for high resolution satellite images. Developed system will be adapted and operated to receive, process and distributes images acquired from of the second Korean Multi-purpose Satellite (KOMPSAT-2), which will be launched in 2004. This project had initiated to develop and Koreanize the state-of-the-art technologies related to the ground receiving system fur high resolution remote sensing images, which range from direct ingestion of image data to the distribution of products through precise image correction. During four years development, the system has been verified in various ways including real operation of custom-made systems such as a prototype system for SPOT and a commercialised system for KOMPSAT-1. Currently the system is under customisation for installation at KOMPSAT-2 ground station. In this paper, we present accomplished work and future work. -
According to the image level definition for KOMPSAT-2 in KOMPSAT-2 Ground Station Specification, the level 0 is frame formatted, unprocessed data at full resolution; any and all communications artifacts (e.g., synchronization frames, communications headers) removed. The level 0 is used for two purposes: 1) exchange of imagery between image receiving & processing element (IRPE), and 2) image transfer from the Receiving & Archiving Subsystem to Search & Processing Subsystem. On-board processing of imagery data of KOMPSAT-2 includes JPEG-like compression and encryption besides conventional CCSDS packetization. The encryption is used to secure imagery data from any intervention during downlink and compression allows real-time downlink of image data reducing data rate produced from the camera. While developing ground receiving system for KOMPSAT-2, it was necessarily to define level 0 products. In this paper, we will suggest level 0 product definition for KOMPSAT-2 and explain reasons of the decisions made. The key factor used while defining the level 0 products is the efficiency of whole ground receiving system. The latter half of the paper will explain the implementation of software that generates level 0 products. The necessary steps to produce level 0 products will be explained, and the performance achieved will be presented.
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MSC as a payload of KOMPSAT-2 is an optical telescope for earth imaging on a sun-synchronous orbit. The MSC is a Ritchey-Chretien type telescope composed of hyperbolic primary and secondary mirrors with focal correcting lenses. Their relative positions should be kept aligned during imaging operation. However, the MSC is exposed to adverse thermal environment on orbit which can have some impacts on optical performance as well as structural endurance. Solar incidence can cause non-uniform temperature rise on the tube which entails unfavorable thermal distortion. Three options were proposed, which were internal shield, external mechanical shield and spacecraft maneuvering. After the trade-off studies, internal sun shield was selected as a realistic and optimal solution to minimize the effect of the solar radiation. In this paper, pros and cons are explained for the three possible choices and a design of the internal shield is discussed.
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The KOMPSAT-2 DCSU(the data compression & storage unit) performs the acquisition of image data from cameras, the compression with requested compression rate, the storage with specified file ID on the mission command and the distribution to the assigned DLS(Data Link System) channels per the mission and operation requirements. The worldwide observation using the MSC is able to be achieved by this DCSU's behavior. This paper presents the features of KOMPSAT-2 DCSU and provides proper ground operation concept after launch.
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MediaGIS is a concept of tightly integrated multimedia with spatial information. VideoGIS is an example of MediaGIS focused on the interaction or interaction of video and spatial information. Our suggested GeoVideo, a new concept of VideoGIS has its key feature in interactiveness. In GeoVideo, the geographic tasks such as browsing, searching, querying, spatial analysis can be performed based on video itself. GeoVideo can have the meaning of paradigm shift from artificial, static, abstracted and graphical paradigm to natural, dynamic, real, and image-based paradigm. We discuss about the integration of video and geography and also suggest the GeoVideo system design. Several considerations on expanding the functionalities of GeoVideo are explained for the future works.
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As diverse researches are working about location acquisition, storing method, data modeling and query processing of moving objects, the moving object database systems, which can gain, store and manage location information and query processing, are tuning up. As the mobile device is moving but have constraints, the convenience user interface for spatio-temporal query and viewing query result needs. In this paper, we designed user Interface for spatio-temporal query related moving objects, viewing query result, tracing current and past location of those and monitoring. And we designed system for implementation of these interfaces.
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Recently, PDA and cellular phone with color LCD have been widely used in various fields by high efficiency and micro miniaturization technology. According to maturity of these mobile environments, user request about mobile application field is increased. Mobile applications provide various information which is concerned with user's position through cable and wireless transmission. This paper discusses the issues related to the mobile framework for integrated 4S data. The integrated 4S data mean spatial data fusion on GIS, SIIS, ITS, and GNSS. The mobile framework provides not only spatial data but also location services such as reverse geocoding, directory service, etc. It consists of client subsystem, service provider, and data provider.
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A provision of spatial information is expected to make a market explosion in various fields. A distribution of spatial data on wireless mobile environments indicates a huge expansion of mobile technology as well as a spread of geospatial applications. For high quality spatial information, 4S technology project integrating 4 kinds of spatial systems is currently being executed with the goal of nationwide integration of spatial data and spatial information systems. In terms of network environments, a mobile ad hoc network where mobile terminals communicate with each other without any infrastructures has been standardized for the next generation mobile wireless network. With respect to the future technologies for spatial information, it is necessary to design 4S applications on mobile ad hoc networks. This paper addresses the issue, which is proposing design points for distributing 4S spatial data on mobile ad hoc networks and ad hoc styled 4S applications.
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This paper described some applications using Open GIS Component that was called MapBase. There were 4 applications : KSDI(Korea Spatial Data Infrastructure) funded by MOIC(Ministry of Information and Communication), National Plants Resource Management System supported by Korea Forest Service, 7-Underground Facilities Management System of Cheongju funded by MOCT(Ministry of Construction and Transportation), and National Disaster Management System supported by MOGAHA(Ministry of Government Administration and Home Affairs. Because they wanted to access heterogeneous spatial database, it was necessary to select MapBase as their base methodology. The main feature of MapBase was component S/W which provided the interoperability and reusability among GIS applications as well as non-GIS information system through common specification. In this paper, we showed some applications' architectures and functions to increase understanding MapBase. That would help you to make application using MapBase.
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Location Based Services, or LBS refers to value-added service by processing information utilizing mobile user location. With the rapidly increasing wireless internet subscribers and world LBS market, the various location based applications are introduced such as buddy finder, proximity and security services. As the killer application of the wireless internet, the LBS has preconsidered technology about location determination technology, LBS middleware server for various application, and diverse contents processing technology. This paper describes the open architecture for LBS platform ensuring interoperability among the wireless networks and various location-based application services and the functional requirements for the LBS platform. The LBS platform in a narrow sense provides a standard interfaces for location management and network management for location services as follows, positioning (location acquisition through network or/and handset), location managing, location based functions, profile management, authentication and security, location based billing, information roaming between carriers and the system monitoring independent to specific network or ISP/CPs(Content Providers).
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Traditionally, Geographical Information Systems can only process spatial data in a procedure-oriented way, and the data can't be treated integrally. This method limits the development of spatial data applications. A new and promising method to solve this problem is the spatial structural query language, which extends SQL and provides integrated accessing to spatial data. In this paper, the theory of spatial structural query language is discussed, and a new geographical data model based on the concepts and data model in OGIS is introduced. According to this model, we implemented a spatial structural query language G/SQL. Through the studies of the 9-Intersection Model, G/SQL provides a set of topological relational predicates and spatial functions for GIS application development. We have successfully developed a Web-based GIS system-WebGIS-using G/SQL. Experiences show that the spatial operators G/SQL offered are complete and easy-to-use. The BNF representation of G/SQL syntax is included in this paper.
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According to the development of computer technology, especially in 3D graphics and visualization, the interest for 3D GIS has been increasing. Several commercial GIS softwares are ready to provide 3D function in their traditional 2D GIS. However, most of these systems are focused on visualization of 3D objects and supports few analysis functions. Therefore in this paper, we design not only a spatial operation processor which can support spatial analysis functions as well as 3D visualization, but also implement a prototype to operate them. In order to support interoperability between the existing models, the proposed spatial operation processor supports the 3D spatial operations based on 3D geometry object model which is designed to extend 2D geometry model of OGIS consortium, and supports index based on R
$^*$ -Tree. The proposed spatial operation processor can be applied in 3D GIS to support 3D analysis functions. -
As Geographic Information Systems represents three-dimensional topological Information, the systems provide accurate and delicate services for user. In order to execute three-dimensional topological operations, a dimensional transformation and heterogeneous spatial models should be used. However, the existing systems that use the dimensional transformation and the heterogeneous models, are not only difficult to operate the spatial operators, but also happened to support non- interoperability. Therefore, in order to support the spatial operation as well as interoperability between dimensions, we propose three-dimensional spatial operators for the proposed models. We defined the three-dimensional spatial operators prior to designing the proposed model. We also implemented the operators of proposed model and evaluated the implemented model on the component environment. Finally, the proposed model is able to not only support interoperability among systems but also execute spatial queries efficiently on three-dimensional spatial objects.
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Currently there are numerous papers in which many new kinds of customizing stereotypes by UML extension mechanism for different application environments such as real-time system, Geographic Information System (GIS) and so on are proposed. However , these stereotypes that represent different type model elements such as class, association, generalization and so on have not yet been seen in one of the most popular visual modeling tool for software development, Rational Rose. Therefore, in this paper, a design of extended iconic stereotype for GNSS application in the UML class diagram and its implementation as a tool of StereotypeCreator for Rational Rose will be presented.