• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.637-640
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• 2005

In the development of a electronic system for a optical payload comprising mainly EOS(Electro-Optical Sub-system) and PDTS(Payload Data Transmission Sub-system), many aspects should be investigated and discussed for the easy implementation, for th e higher reliability of operation and for the effective ness in cost, size and weight as well as for the secure interface with components of a satellite bus, etc. As important aspects the interfaces between a satellite bus and a payload, and some design features of the CEU(Camera Electronics Unit) inside the payload are described in this paper. Interfaces between a satellite bus and a payload depend considerably on whether t he payload carries the PMU(Payload Management Un it), which functions as main controller of the Payload, or not. With the PMU inside the payload, EOS and PDTS control is performed through the PMU keep ing the least interfaces of control signals and primary power lines, while the EOS and PDTS control is performed directly by the satellite bus components using relatively many control signals when no PMU exists inside the payload. For the CEU design the output channel configurations of panchromatic and multi-spectral bands including the video image data inter face between EOS and PDTS are described conceptually. The timing information control which is also important and necessary to interpret the received image data is described.

• International Journal of Computer Science & Network Security
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• v.23 no.3
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• pp.94-100
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• 2023

The primary goal of any communication spacecraft is to provide communication in variety of frequency bands based on mission requirements within the Indian mainland. Some of the spacecrafts operating in S-band utilizes a 6m or larger aperture Unfurlable Antenna (UFA for S-band links and provides coverage through five or more S-band spot beams over Indian mainland area. The Unfurlable antenna is larger than the satellite and so the antenna is stowed during launch. Upon reaching the orbit, the antenna is deployed using motors. The deployment status of any deployment mechanism will be monitored and verified by the telemetered values of micro-switch position before the start of deployment, during the deployment and after the completion of the total mechanism. In addition to these micro switches, a camera onboard will be used for capturing still images during primary and secondary deployments of UFA. The proposed checkout system is realized for validating the performance of the onboard camera as part of Integrated Spacecraft Testing (IST) conducted during payload checkout operations. It is designed for acquiring the payload data of onboard camera in real-time, followed by archiving, processing and generation of images in near real-time. This paper presents the architecture, design and implementation features of the acquisition, processing and Image generation system for Camera onboard spacecraft. Subsequently this system can be deployed in missions wherever similar requirement is envisaged.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.4
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• pp.217-233
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• 2020

This study evaluated the urban vitality of Daegu metropolitan city in 2018 using emerging geographic data such as spatial big data, Wi-Fi AP(access points) and nighttime light satellite image. The emerging geographic data were used in this research to quantify human activities in the city more directly at various spatial and temporal scales. Three spatial big data such as mobile phone data, credit card data and public transport smart card data were employed to reflect social, economic and mobility aspects of urban vitality while public Wi-Fi AP and nighttime light satellite image were included to consider virtual and physical aspects of the urban vitality. With PCA (Principal Component Analysis), five indicators were integrated and transformed to the urban vitality index at census output area by temporal slots. Results show that five clusters with high urban vitality were identified around downtown Daegu, Daegu bank intersection and Beomeo intersection, Seongseo, Dongdaegu station and Chilgok 3 district. Further, the results unveil that the urban vitality index was varied over the same urban space by temporal slots. This study provides the possibility for the integrated use of spatial big data, Wi-Fi AP and nighttime light satellite image as proxy for measuring urban vitality.

• Proceedings of the KSRS Conference
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• v.1
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• pp.409-412
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• 2006

Today's commercial high resolution satellite imagery such as IKONOS and QuickBird, offers the potential to extract useful spatial information for geographical database construction and GIS applications. Recognizing this potential use of high resolution satellite imagery, KARI is performing a project for developing Korea multipurpose satellite 3(KOMPSAT-3). Therefore, it is necessary to develop techniques for various GIS applications of KOMPSAT-3, using similar high resolution satellite imagery. As fundamental studies for this purpose, we focused on the extraction of 3D spatial information and the update of existing GIS data from QuickBird imagery. This paper examines the scheme for rectification of high resolution image, and suggests the convenient semi-automatic algorithm for extraction of 3D building information from a single image. The algorithm is based on triangular vector structure that consists of a building bottom point, its corresponding roof point and a shadow end point. The proposed method could increase the number of measurable building, and enhance the digitizing accuracy and the computation efficiency.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.320-323
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• 2008

This study attempts to establish a system extracting and monitoring cultural grounds of seaweeds (lavers, brown seaweeds and seaweed fulvescens) and abalone on the basis of both KOMPSAT-2 and Terrasar-X data. The study areas are located in the northwest and southwest coast of South Korea, famous for coastal cultural grounds. The northwest site is in a high tidal range area (on the average, 6.1 min Asan Bay) and has laver cultural grounds for the most. An semi-automatic detection system of laver facilities is described and assessed for spacebome optic images. On the other hand, the southwest cost is most famous for seaweeds. Aquaculture facilities, which cover extensive portions of this area, can be subdivided into three major groups: brown seaweeds, capsosiphon fulvescens and abalone farms. The study is based on interpretation of optic and SAR satellite data and a detailed image analysis procedure is described here. On May 25 and June 2, 2008 the TerraSAR-X radar satellite took some images of the area. SAR data are unique for mapping those farms. In case of abalone farms, the backscatters from surrounding dykes allows for recognition and separation of abalone ponds from all other water-covered surfaces. But identification of seaweeds such as laver, brown seaweeds and seaweed fulvescens depends on the dampening effect due to the presence of the facilities and is a complex task because objects that resemble seaweeds frequently occur, particularly in low wind or tidal conditions. Lastly, fusion of SAR and optic spatial images is tested to enhance the detection of aquaculture facilities by using the panchromatic image with spatial resolution 1 meter and the corresponding multi-spectral, with spatial resolution 4 meters and 4 spectrum bands, from KOMPSAT-2. The mapping accuracy achieved for farms will be estimated and discussed after field verification of preliminary results.

• Proceedings of the KSRS Conference
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• 2007.03a
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• pp.308-310
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• 2007

복사 보정에 해당하는 NUC(Non-Uniformity Correction)은 MSC 각각의 픽셀들이 가지는 상이한 특성을 균일한 이미지를 얻기 위해 보정하는 작업으로서 KOMPSAT-2 검보정 작업 중 Video Processor 의 Electrical Gain/Offset 의 보정 과 더 불어 매 우 중요한 비중을 차지하는 과정이다. 본 논문에서는 KOMPSAT-2 의 Panchromatic 밴드의 raw image 를 이 용한 NUC 보정 작업 의 과정과 그 결과에 대해서 소개하고자 한다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10b
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• pp.655-657
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• 2003

This study is on the characteristics of discriminating of image using unique electric wave intensity value from satellite images data. Namely this study is on studying specific image characteristics by image spectrum and is on developing procedures discriminating of water, forest. narrow-leaved(coniferous) trees, broad-leaved(deciduous) trees, terrain, farmland, grassland, etc. using unique spectrum value in material. Finally applying this procedures, we design and implement discriminating system, IDEA(Information Discriminating Extracting Agent).

• Journal of Astronomy and Space Sciences
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• v.25 no.4
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• pp.445-458
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• 2008

Image chain analysis of synthetic aperture radar (SAR) satellite is one of the primary activities for satellite design because SAR image quality depends on spacecraft bus performance as well as SAR payload. Especially, satellite pointing and stability error make worst effect on the original SAR image quality which is implemented by SAR payload design. In this research, Image chain analysis S/W was developed in order to analyze the SAR image quality degradation due to satellite pointing and stability error. This S/W consists of orbit model, attitude control model, SAR payload model, clutter model, and SAR processor. SAR raw data, which includes total 25 point targets in the scene of $5km{\times}5km$ swath width, was generated and then processed for analysis. High resolution mode (spotlight), of which resolution is 1m, was applied. The results of image chain analysis show that radiometric accuracy is the most degraded due to the pointing error. Therefore, the successful design of attitude control subsystem in spacecraft bus for enhancing the pointing accuracy is most important for image quality.

• Convergence Security Journal
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• v.17 no.5
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• pp.41-47
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• 2017

The Marine Environment Observation Information System supplies oceanographic information elements such as water temperature, chlorophyll, float, etc. based on satellite images to consumers. The data produced by the Korean marine environmental observatories are located in the coastal areas of Korea. But if the range is too far from a particular area of interest, due to distance or spatial constraints, the accuracy and up-to-dateness of the data can not be relied upon. Therefore, it is necessary to perform fusion and complex operation to solve the difference between the field observation and the marine satellite image. In this study, we develop a system that can process marine environmental information in the user's area of interest in the form of layered character (numeric) information considering the readability and light weight rather than the satellite image. In order to intuitively understand satellite image information, we characterize (quantify) the marine environmental information of the area of interest and we process the satellite image band values into layered characters to minimize the absolute amount of transmitted / received data. Also we study modular location-based interest information service method to be able to flexibly extend and connect interested items that diversify various observation fields as well as application technology to serve this.

• Journal of Cadastre & Land InformatiX
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• v.53 no.1
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• pp.107-121
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• 2023

In order to acquire a wide range of land that changes in real time and quickly and accurately grasp it, we plan to utilize the recently released high-resolution S.Korea's satellite image data and artificial intelligence (AI). Compared to existing satellite images, the spectral and periodic resolutions of S.Korea's satellite are higher, making them a more suitable data source for periodically monitoring changes in land. Therefore, this study aims to acquire S.Korea's satellite, select 8 types of objects to detect land changes, construct data sets for them, and apply AI models to analyze them. In order to confirm the optimal model and variable conditions for detecting 8 types of objects of various types, several experiments are performed and AI-based image analysis is technically reviewed.