• Title/Summary/Keyword: satellite Imagery

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Linking of Accessibility Index Extraction by Transportation Gravity Model and High-Resolution Satellite Imagery (위성영상정보와 교통 중력모델기반 접근성지수 추출 연계)

  • 이기원
    • Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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    • 2003.04a
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    • pp.562-567
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    • 2003
  • 최근 고해상도 위성영상정보의 민간 사용이 활발해지면서 기존에 널리 알려진 위성영상정보 응용분야 뿐만 아니라 새로운 응용 분야에 대한 적용 가능성이 국제적으로 여러 가지 방향으로 모색되고 있다. 본 연구는 이러한 추세를 반영하여 교통 또는 도시교통 환경분야에서의 위성영상정보의 활용 가능성 및 기존 방법론과의 연계를 분석하고, 시험적으로 프로토타입 프로그램을 소개하고자 한다. 일반적으로 교통문제에서의 접근성 분석은 일종의 중력모델로 설명이 가능하며, 교통계획 수립시에 대안 도로 계획선정이나 대중교통 노선결정시에 많이 이용되고 있다. 접근성 분석에 대한 개념은 비교적 간단하여, 교통분석대상구역의 임의 지역에서 유인 요인과 거리를 변수로 하여 적용 목적에 부합되는 대상 지점까지의 정량적 지수정보를 얻도록 하여 몇 가지 결과로부터 출발지점에서 목적지점 또는 대상 지점까지의 손익비용산출에 대한 정보를 얻는 방식이다. 최근에 GIS를 통하여 구축된 교통 데이터베이스정보와 공간분석 기법을 통하여 수행하는 경우가 많으나 현재까지 위성영상정보가 이용된 경우는 거의 보고된 바가 없다. 따라서 본 연구에서는 정사위성 실제 교통시설물이나 교통 대상 객체의 육안 식별이 가능한 고 해상도 위성영상정보는 이러한 출발지-목적지 선정에 적용될 수 있다는 점에 착안하여 기존에 교통분야에서 개발된 몇 가지의 교통 접근성 산출 알고리듬에 위성영상정보가 연계되어 적용될 수 있는 가능성을 검토하였다.

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Otter Habitat Analysis and Regional Development Strategies in Dadohae National Park Using GIS Techniques (GIS기법을 이용한 다도해국립공원의 수달 서식가능지 분석과 지역개발 정책에 관하여)

  • Chang, Eun-Mi;Park, Kyeong;Chae, Hee-Young
    • Spatial Information Research
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    • v.16 no.3
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    • pp.343-357
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    • 2008
  • Hongdo and Huksando belong to the Dadohae national park parks in Korea and are famous sightseeing spots in Shinahn-gun. One of the keystone species in this area is otter (Lutra lutra). We accomplished field works for finding its present habitat and condition analyses for the potential habitat in the area via spatial analyses with digital elevation model and satellite imagery. Isolated condition with coastal cliffs was one of the superior conditions over habitat in the main land, but the road kills of small animals were also observed. Three underground eco-corridors were suggested for the protection of otter habitat in the Shinahn-gun area. Regional development strategies of Shinahn-gun should be focused on the protection of safe and pristine habitat for otter population.

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Study of Urban Land Cover Changes Relative to Demographic and Residential Form Changes: A Case Study of Wonju City, Korea

  • Han, Gab-Soo;Kim, Mintai
    • Journal of Forest and Environmental Science
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    • v.31 no.4
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    • pp.288-296
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    • 2015
  • In many very high density cities in Asia in which there is limited area to expand, growth is forced upward as well as outward. Densely packed detached houses and low-rise buildings are replaced by lower density high-rises, leaving open spaces between high-rise buildings. Through this process, areas that formerly did not have much green space gain valuable green spaces, and new ecological corridors and patches are created. In this study, the demographic and housing-type changes of Wonju City were delineated using land use maps, aerial images, census data, and other administrative data. Green area changes were calculated using land cover data derived from multi-year Landsat TM satellite imagery. The values were then compared against demographic and housing-type changes for each administrative unit. The overall results showed a decrease of forested area in the city and an increase of developed area. Urban sprawl was clearly visible in many of the suburban areas. However, as expected, we also detected areas in which greenness did not decrease when the population greatly increased. These areas were characterized by residential building complexes of ten or more stories. If an equal number of housing units had been built as detached houses, these areas would not have kept as much green space. Our research result showed that high-density and high-rise residential structures can offer an alternative means to protect or create urban green spaces in high-density urban environments.

On the occurrence of yellow sand and atmospheric loadings (황사의 사례분석과 한반도 유입량)

  • 정용승;윤마병
    • Journal of Korean Society for Atmospheric Environment
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    • v.10 no.4
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    • pp.233-244
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    • 1994
  • The phenomenon of yellow sand (dust clouds) occurred in Korea during the spring of 1993 and 1994 is studied in detail. In total 6 cases including 15 days of yellow sand were observed in 1993 and the annual number of these events was found to increased. Examinations in this study include meteorological charts satellite imagery, pilot reports (PIREP) of Korea Air Force, and air concentrations of total suspended particulates(TSP). We present on estimation of total atmospheric loadings based on the observation and theory. According to the PIREP, in general the dust clouds travelled in the lower troposphere up to the level 5km. The visibility within the clouds was in the range of 3-8km The area covered by yellow sand in an event exceeded 0.4 M $\textrm{km}^2$ . According to trajectory analyses, dust clouds invaded Korea in April and May 1993 were landed in the sink area after 2~4 days travelling for 2,000~3,000km from a source region. Estimates of total atmospheric loadings of a dust cloud for April 23~24 in 1993 were 1.5 M ton. In addition, 7 dust storms were also reported in synoptic observations in NW China and Mongolia during the spring in 1994. The yellow sand was not reported with meteorological observations in Korea, however pilots reported significant dust clouds over the Yellow Sea on 8 and 13 April and 20 May 1994.

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Utilizing GSIS and High Resolution Satellite Imagery for Landform Analysis and Sight-Seeing Guidance (금오산 도립공원의 지형분석과 관광안내를 위한 GSIS와 고해상도 위성영상의 활용)

  • Lee, Jin-Duk;Choi, Young-Geun;Lee, Ho-Chan
    • 한국지형공간정보학회:학술대회논문집
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    • 2002.03a
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    • pp.156-161
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    • 2002
  • 자연공원의 체계적인 관리를 위해서는 효율적인 자료수집과 처리, 그리고 합리적인 분석과정이 필요하며, 이러한 관점에서 지형공간정보체계와 위성원격탐사를 이용하는 공원관리 및 관광안내시스템의 개발이 요구되는 시점이다. 본 연구에서는 금오산 도립공원구역을 사례연구지역으로 GSIS(Geo-Spatial Information System)기법을 도입하여 수치지형도, 주제도, 위성영상 등으로부터 도형자료 및 비도형자료를 수집 처리하였다. DEM 생성을 통하여 얻어진 경사도, 사면방향, 지형단면, 지질 분석 등 주제별 지형분석을 행하였다. Landsat TM 위성자료로부터 토지피복분류와 NDVI 식생활력도를 추출하였고, 이 자료들로부터 GSIS 데이터베이스를 구축하였다. 또한 대상지역을 포함하는 Im 해상도의 IKONOS 위성자료를 처리하여 영상지도를 작성하고 DEM과 중합하여 3D 시각화를 구현하였다. 위성영상지도 및 3차원 경관도상에 주요 등산로 벡터자료를 중첩하여 표현하고, 5개 루트의 주요 등산로를 따라 3D 경관 및 문화재, 관리시설 등을 포함하는 동영상 파일을 제작하였다. 본 연구의 결과는 개발과 보존의 중도를 취하는 자연공원의 적정 토지이용을 위한 사전평가 자료 및 Web 기반 관광안내시스템을 구축하기 위한 기본데이터로 활용될 수 있을 것이다.

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EVOLUTION OF INTERNAL WAVES NEAR A TURNING POINT IN THE SOUTH CHINA SEA USING SAR IMAGERY AND NUMERICAL MODELS

  • Kim, Duk-Jin;Lyzenga, David R.;Choi, Woo-Young;Kim, Youn-Soo
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.61-64
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    • 2007
  • Subsurface Internal Waves (IWs) can be detected in satellite images as periodic alternating brighter/darker stripes. It is known that there are two types of IWs - depression type and elevation type - depending on the water depth in stratified oceans. In this study, we have quantitatively verified the process of converting polarity from depression waves to elevation waves using ERS-2 SAR images acquired over the northern South China Sea. We simulated the evolution of IWs near a turning point with a numerical model for internal wave propagation. The simulation results near the turning point clearly showed us not only a conversion process of IWs from depression to elevation waves, but also a similar wave pattern with the observed SAR image. We also simulated SAR intensity variation near the turning point. The upper layer currents were computed at regular intervals using the numerical model, as the IWs were passing through the turning point. Then, an integrated hydrodynamic-electromagnetic model was used for simulating SAR intensity profiles from the upper layer currents at each position. The simulated SAR intensity profiles at each position were compared with the observed SAR intensities.

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An Effective Urbanized Area Monitoring Method Using Vegetation Indices

  • Jeong, Jae-Joon;Lee, Soo-Hyun
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.598-601
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    • 2007
  • Urban growth management is essential for sustainable urban growth. Monitoring physical urban built-up area is a task of great significance to manage urban growth. Detecting urbanized area is essential for monitoring urbanized area. Although image classifications using satellite imagery are among the conventional methods for detecting urbanized area, they requires very tedious and hard work, especially if time-series remote sensing data have to be processed. In this paper, we propose an effective urbanized area detecting method based on normalized difference vegetation index (NDVI) and normalized difference built-up index (NDBI). To verify the proposed method, we extract urbanized area using two methods; one is conventional supervised classification method and the other is the proposed method. Experiments shows that two methods are consistent with 98% in 1998, 99.3% in 2000, namely the consistency of two methods is very high. Because the proposed method requires no more process without band operations, it can reduce time and effort. Compared with the supervised classification method, the proposed method using vegetation indices can serve as quick and efficient alternatives for detecting urbanized area.

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MODIFIED DOUBLE SNAKE ALGORITHM FOR ROAD FEATURE UPDATING OF DIGITAL MAPS USING QUICKBIRD IMAGERY

  • Choi, Jae-Wan;Kim, Hye-Jin;Byun, Young-Gi;Han, You-Kyung;Kim, Yong-Il
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.234-237
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    • 2007
  • Road networks are important geospatial databases for various GIS (Geographic Information System) applications. Road digital maps may contain geometric spatial errors due to human and scanning errors, but manually updating roads information is time consuming. In this paper, we developed a new road features updating methodology using from multispectral high-resolution satellite image and pre-existing vector map. The approach is based on initial seed point generation using line segment matching and a modified double snake algorithm. Firstly, we conducted line segment matching between the road vector data and the edges of image obtained by Canny operator. Then, the translated road data was used to initialize the seed points of the double snake model in order to refine the updating of road features. The double snake algorithm is composed of two open snake models which are evolving jointly to keep a parallel between them. In the proposed algorithm, a new energy term was added which behaved as a constraint. It forced the snake nodes not to be out of potential road pixels in multispectral image. The experiment was accomplished using a QuickBird pan-sharpened multispectral image and 1:5,000 digital road maps of Daejeon. We showed the feasibility of the approach by presenting results in this urban area.

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THE LAND COVER MAPPING IN NORTH KOREA USING MODIS IMAGE;THE CLASSIFICATION ACCURACY ENHANCEMENT FOR INACCESSIBLE AREA USING GOOGLE EARTH

  • Cha, Su-Young;Park, Chong-Hwa
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.341-344
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    • 2007
  • A major obstacle to classify and validate Land Cover maps is the high cost of generating reference data or multiple thematic maps for subsequent comparative analysis. In case of inaccessible area such as North Korea, the high resolution satellite imagery may be used as in situ data so as to overcome the lack of reliable reference data. The objective of this paper is to investigate the possibility of utilizing QuickBird (0.6m) of North Korea obtained from Google Earth data provided thru internet. Monthly NDVI images of nine months from the summer of 2004 were classified into L=54 cluster using ISODATA algorithm, and these L clusters were assigned to 7 classes; coniferous forest, deciduous forest, mixed forest, paddy field, dry field, water and built-up area. The overall accuracy and Kappa index were 85.98% and 0.82, respectively, which represents about 10% point increase of classification accuracy than our previous study based on GCP point data around North Korea. Thus we can conclude that Google Earth may be used to substitute the traditional in situ data collection on the site where the accessibility is severely limited.

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Changes in Topics of Surveying related Papers in Korea - Phase I (국내 측량 관련 논문 주제의 변천 I)

  • 김병국;김은모;최정민
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.13 no.2
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    • pp.245-275
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    • 1995
  • Surveying related papers and books presented and published since 1957 in Korea are investigated and gathered, and the list by the topics of the papers is prepared. And changes in the topics of surveying related researches are studied through the changes in the titles of the presented papers. The fields of general surveying and photogrammetry have been doing their role to lead surveying researches since 1957, and those of Geodesy, Remote Sensing, GIS and GPS are rapidly growing as advanced fields. Especially GIS is a widespreading field as being used in many socio-environment parts, recently gets a big attentions by the National GIS Project. GPS and Remote Sensing have contributed to make the surveying area an advanced technology by employing newly developed technigues to GPS receivers and satellite imagery.

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