• Title/Summary/Keyword: Geospatial Data

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Geocoding Scheme for Multimedia in Indoor Space Based on IndoorGML (IndoorGML을 활용한 실내공간 멀티미디어 위치 인코딩 방법)

  • Li, Ki Joune
    • Spatial Information Research
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    • v.21 no.4
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    • pp.35-45
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    • 2013
  • Most multimedia contains location information whether they are implicit or explicitly, and which are very useful for several purposes. In particular, we may use location information in defining query conditions to retrieve relevant multimedia. For this reason, a number of works have been done to organize and retrieve geo-referenced multimedia data. However, they mostly focus on outdoor space where position is identified by (x, y, z) coordinates. In this paper, we focus on multimedia in an alternative space, indoor space, which differs from outdoor space in several aspects. First indoor space is considered as symbolic space, where location is identified by a symbolic code such as room number rather than coordinates. Second, topological information is a crucial element in providing indoor spatial information services. Third, indoor space is in more micro-scale than outdoor space, which influences on determining the visibility of cameras. Based on these different characteristics of indoor space, we survey the requirements of management systems of indoor geo-referenced multimedia. Then we propose a geo-coding scheme for multimedia in indoor space as an extension of IndoorGML, an OGC(Open Geospatial Consortium) candidate standard for indoor spatial information. We also present a prototype system called, IngC (INdoor Geo-Coding) developed to store and manage indoor geo-referenced multimedia.

Spatial-Sensor Observation Service for Spatial Operation of GeoSensor (GeoSensor의 공간연산을 확장한 Spatial-Sensor Observation Service)

  • Lee, Hyuk;Lee, Yeon;Chung, Weon-Il;Bae, Hae-Young
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.11
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    • pp.35-44
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    • 2011
  • Advances in science and technology have made a lot of changes in our life. Especially, sensors have used in various ways to monitor in real time and analyze the world effectively. Traditional sensor networks, however, have used their own protocols and architecture so it had to be paid a lot of additional cost. In the past 8 years, OGC and ISO have been formulating standards and protocols for the geospatial Sensor Web. Although the OGC SWE initiatives have deployed some components, attempts have been made to access sensor data. All spatial operations had to calculate on the client side because traditional SOS architecture did not consider spatial operation for GeoSensor. As a result, clients have to implement and run spatial operations, and it caused a lot of overload on them and decreased approachableness. In this paper we propose S-SOS for in-situ and moving GeoSensor that extends 52 North SOS and provides spatialFilter and spatialFinder operations. The proposed S-SOS provides an architecture that does not need to edit already deployed SOSs and can add spatial operations as occasion. Additionally we explain how to express the spatial queries and to be used effectively for various location based services.

Analysis of Thermal Heat Island Potential by Urbanization Using Landsat-8 Time-series Satellite Imagery (Landsat-8 시계열 위성영상을 활용한 도심지 확장에 따른 열섬포텐셜 분석)

  • Kim, Taeheon;Lee, Won Hee;Han, Youkyung
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.36 no.4
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    • pp.305-316
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    • 2018
  • As the urbanization ratio increases, the heat environment in cities is becoming more important due to the urban heat island. In this study, the heat island spatial analysis was calculated and conducted for analysis of urban thermal environment of Sejong city, which was launched in 2012 and has been developed rapidly. To analyze the ratio and change rate of urban area, a multi temporal land cover map (2013 to 2015 and 2017) of study area is generated based on Landsat-8 OLI/TIRS (Operational Land Imager / Thermal Infrared Sensor) satellite imagery. Then, we select an TIR (Thermal Infrared) band from the two TIR bands provided by the Landsat-8, which is used for calculating the heat island potential, through the accuracy evaluation of the brightness temperature and AWS (Automatic Weathering Station) data. Based on the selected band and surface emissivity, land surface temperature is calculated and the estimated heat island potential change is analyzed. As a result, the land surface temperature of the high ratio and change rate of urban area was significantly higher than the surrounding area around $3^{\circ}C$ to $4^{\circ}C$, and the heat island potential was also higher around $4^{\circ}C$ to $5^{\circ}C$. However, the heat island phenomenon was alleviated in urban areas with high rate of change that also show high green area ratio. Therefore, we demonstrated that dense urban area increases the possibility of inducing heat island, but it can mitigate the heat island through green areas.

RPC Model Generation from the Physical Sensor Model (영상의 물리적 센서모델을 이용한 RPC 모델 추출)

  • Kim, Hye-Jin;Kim, Jae-Bin;Kim, Yong-Il
    • Journal of Korean Society for Geospatial Information Science
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    • v.11 no.4 s.27
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    • pp.21-27
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    • 2003
  • The rational polynomial coefficients(RPC) model is a generalized sensor model that is used as an alternative for the physical sensor model for IKONOS-2 and QuickBird. As the number of sensors increases along with greater complexity, and as the need for standard sensor model has become important, the applicability of the RPC model is also increasing. The RPC model can be substituted for all sensor models, such as the projective camera the linear pushbroom sensor and the SAR This paper is aimed at generating a RPC model from the physical sensor model of the KOMPSAT-1(Korean Multi-Purpose Satellite) and aerial photography. The KOMPSAT-1 collects $510{\sim}730nm$ panchromatic images with a ground sample distance (GSD) of 6.6m and a swath width of 17 km by pushbroom scanning. We generated the RPC from a physical sensor model of KOMPSAT-1 and aerial photography. The iterative least square solution based on Levenberg-Marquardt algorithm is used to estimate the RPC. In addition, data normalization and regularization are applied to improve the accuracy and minimize noise. And the accuracy of the test was evaluated based on the 2-D image coordinates. From this test, we were able to find that the RPC model is suitable for both KOMPSAT-1 and aerial photography.

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A Prospect on the Changes in Short-term Cold Hardiness in "Campbell Early" Grapevine under the Future Warmer Winter in South Korea (남한의 겨울기온 상승 예측에 따른 포도 "캠벨얼리" 품종의 단기 내동성 변화 전망)

  • Chung, U-Ran;Yun, Jin-I.
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.10 no.3
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    • pp.94-101
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    • 2008
  • Warming trends during winter seasons in East Asian regions are expected to accelerate in the future according to the climate projection by the Inter-governmental Panel on Climate Change (IPCC). Warmer winters may affect short-term cold hardiness of deciduous fruit trees, and yet phenological observations are scant compared to long-term climate records in the regions. Dormancy depth, which can be estimated by daily temperature, is expected to serve as a reasonable proxy for physiological tolerance of flowering buds to low temperature in winter. In order to delineate the geographical pattern of short-term cold hardiness in grapevines, a selected dormancy depth model was parameterized for "Campbell Early", the major cultivar in South Korea. Gridded data sets of daily maximum and minimum temperature with a 270m cell spacing ("High Definition Digital Temperature Map", HDDTM) were prepared for the current climatological normal year (1971-2000) based on observations at the 56 Korea Meteorological Administration (KMA) stations and a geospatial interpolation scheme for correcting land surface effects (e.g., land use, topography, and site elevation). To generate relevant datasets for climatological normal years in the future, we combined a 25km-resolution, 2011-2100 temperature projection dataset covering South Korea (under the auspices of the IPCC-SRES A2 scenario) with the 1971-2000 HD-DTM. The dormancy depth model was run with the gridded datasets to estimate geographical pattern of change in the cold-hardiness period (the number of days between endo- and forced dormancy release) across South Korea for the normal years (1971-2000, 2011-2040, 2041-2070, and 2071-2100). Results showed that the cold-hardiness zone with 60 days or longer cold-tolerant period would diminish from 58% of the total land area of South Korea in 1971-2000 to 40% in 2011-2040, 14% in 2041-2070, and less than 3% in 2071-2100. This method can be applied to other deciduous fruit trees for delineating geographical shift of cold-hardiness zone under the projected climate change in the future, thereby providing valuable information for adaptation strategy in fruit industry.

Change Detection of Building Demolition Area Using UAV (UAV를 활용한 건물철거 지역 변화탐지)

  • Shin, Dongyoon;Kim, Taeheon;Han, Youkyung;Kim, Seongsam;Park, Jesung
    • Korean Journal of Remote Sensing
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    • v.35 no.5_2
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    • pp.819-829
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    • 2019
  • In the disaster of collapse, an immediate response is needed to prevent the damage from worsening, and damage area calculation, response and recovery plan should be established. This requires accurate detection of the damage affected area. This study performed the detection of the damaged area by using UAV which can respond quickly and in real-time to detect the collapse accident. The study area was selected as B-05 housing redevelopment area in Jung-gu, Ulsan, where the demolition of houses and apartments in progress as the redevelopment project began. This area resembles a collapsed state of the building, which clear changes before and after the demolition. UAV images were acquired on May 17 and July 9, 2019, respectively. The changing area was considered as the damaged area before and after the collapse of the building, and the changing area was detected using CVA (Change Vector Analysis) the Representative Change Detection Technique, and SLIC (Simple Linear Iterative Clustering) based superpixel algorithm. In order to accurately perform the detection of the damaged area, the uninterested area (vegetation) was firstly removed using ExG (Excess Green), Among the objects that were detected by change, objects that had been falsely detected by area were finally removed by calculating the minimum area. As a result, the accuracy of the detection of damaged areas was 95.39%. In the future, it is expected to be used for various data such as response and recovery measures for collapse accidents and damage calculation.

Improvement of Ortho Image Quality by Unmanned Aerial Vehicle (UAV에 의한 정사영상의 품질 개선 방안)

  • Um, Dae-Yong;Park, Joon-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.11
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    • pp.568-573
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    • 2018
  • UAV(Unmanned Aerial Vehicle) is widely used in space information construction, agriculture, fisheries, weather observation, communication, and entertainment fields because they are cheaper and easier to operate than manned aircraft. In particular, UAV have attracted much attention due to the speed and cost of data acquisition in the field of spatial information construction. However, ortho image images produced using UAVs are distorted in buildings and forests. It is necessary to solve these problems in order to utilize the geospatial information field. In this study, fixed wing, rotary wing, vertical take off and landing type UAV were used to detect distortions of ortho image of UAV under various conditions, and various object areas such as construction site, urban area, and forest area were captured and analysed. Through the research, it was found that the redundancy of the unmanned aerial vehicle image is the biggest factor of the distortion phenomenon, and the higher the flight altitude, the less the distortion phenomenon. We also proposed a method to reduce distortion of orthoimage by lowering the resolution of original image using DTM (Digital Terrain Model) to improve distortion. Future high-quality unmanned aerial vehicles without distortions will contribute greatly to the application of UAV in the field of precision surveying.

Accuracy Analysis of Low-cost UAV Photogrammetry for Corridor Mapping (선형 대상지에 대한 저가의 무인항공기 사진측량 정확도 평가)

  • Oh, Jae Hong;Jang, Yeong Jae;Lee, Chang No
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.36 no.6
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    • pp.565-572
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    • 2018
  • Recently, UAVs (Unmanned Aerial Vehicles) or drones have gained popularity for the engineering surveying and mapping because they enable the rapid data acquisition and processing as well as their operation cost is low. The applicable fields become much wider including the topographic monitoring, agriculture, and forestry. It is reported that the high geospatial accuracy is achievable with the drone photogrammetry for many applications. However most studies reported the best achievable mapping results using well-distributed ground control points though some studies investigated the impact of control points on the accuracy. In this study, we focused on the drone mapping of corridors such as roads and pipelines. The distribution and the number of control points along the corridor were diversified for the accuracy assessment. In addition, the effects of the camera self-calibration and the number of the image strips were also studied. The experimental results showed that the biased distribution of ground control points has more negative impact on the accuracy compared to the density of points. The prior camera calibration was favored than the on-the-fly self-calibration that may produce poor positional accuracy for the case of less or biased control points. In addition, increasing the number of strips along the corridor was not helpful to increase the positional accuracy.

Fishes distribution and their connection to artificial reefs off Bukchon, Jeju Island using geographic information system (지리정보시스템을 활용한 제주도 북촌의 인공어초해역에서 어류 분포와 어초와의 관계)

  • KANG, Myounghee;FAJARYANTI, Rina;JUNG, Bongkyu;YOON, Eun-A;MIN, Eunbi;LEE, Kyounghoon;OH, Woo-Seok;PARK, Geunchang;SHIN, Young-Jae;CHOI, Yong-Suk;YI, Byung-Ho;HWANG, Doojin
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.55 no.2
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    • pp.121-128
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    • 2019
  • Various artificial reefs provide the fish habitat and nursery, and contribute the improvement of fisheries productivity. The evaluation methods of fishery resources in the artificial reefs have been done by fishing, scuba diving, underwater camera, and scientific echo sounder/sonar. There are a number of studies using echosounders on the quantitative and qualitative evaluations of artificial reefs in various seas around the world. This study focused on the spatial distribution of fishes around artificial reefs and the influential area of reefs off Bukchon, Jeju Island. Not only acoustic data but also various properties of artificial reefs were used in the geographic information system to extract relevant results. As a result, the major material of reefs on this study site was concrete and the number of reefs with that material was the most. The volume of reefs consisted of steel only and steel with riprap was considerably large compared to other reefs. The average NASC in the vertical distribution of fishes in artificial reefs was $31.6m^2/nm^2$ in April, and that was $61.3m^2/nm^2$ in June. The distance between the fish school and their nearest reef in June morning had a wide range from 750 to 3250 m. On the basis of the influence ray of artificial reefs, it had a tendancy of NASC to decrease with distance from the reef in the June morning. It is a preliminary study to present the geospatial analysis example to understand a better way of comprehensive artificial reef environments.

A Study on Mitigation Plan of Urban Heat Island Phenomenon Using Landsat Time Series Imagery - Focusing on Cheongna International City - (시계열 Landsat 위성영상을 활용한 도시 열섬 현상 완화 방안에 관한 연구 - 청라 국제도시를 중심으로 -)

  • BAEK, Seon-Uk;KIM, Dong-Hyun;KIM, Hung-Soo;GU, Bon-Yup;CHOUNG, Yun-Jae
    • Journal of the Korean Association of Geographic Information Studies
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    • v.25 no.3
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    • pp.1-16
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    • 2022
  • Areas developed through land reclamation projects have huge economic advantages in terms of supplying lands that can be used for farmlands, urban areas and etc., however have relatively small areas of grasslands and densely located buildings compared to inland cities. Hence, an urban heat island is occurring in these areas due to this characteristic, and in particular, the urban heat island in Cheongna International City is getting serious. In this study, the urban heat island in Cheongna International City was evaluated and analyzed by classified into the three periods after the reclamation project: farmland(2001-2008), development(2009-2013) and artificial grassland(2014-2020). The land cover map and Landsat time-series imagery were utilized for measuring the differences of the land surface temperatures between the urbanized areas and the grassland/forest areas in Cheongna International City. The statistical results showed that the differences in the land surface temperature between these areas were calculated to be at most 0℃ during the period of farmland, at most 3.60℃ during the period of development, and at most 2.51℃ during the period of grassland. This study proved that the urban heat island phenomenon increased when the urbanized areas increased, and the urban heat island phenomenon decreased when the artificial grassland areas increased in Cheongna International City where the reclamation project was carried out. The statistical results derived through this research can be used as the reference data for identifying the urban heat island problem in urban planning and establishing the reduction plan.