• Title/Summary/Keyword: Urban Sensing

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Building Extraction and 3D Modeling from Airborne Laser Scanning Data

  • Lee, Jeong-Ho;Han, Soo-Hee;Byun, Young-Gi;Yu, Ki-Yun;Kim, Yong-Il
    • Korean Journal of Remote Sensing
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    • v.23 no.5
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    • pp.447-453
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    • 2007
  • The demand for more accurate and realistic 3D urban models has been increasing more and more. Many studies have been conducted to extract 3D features from remote sensing data such as satellite images, aerial photos, and airborne laser scanning data. In this paper a technique is presented to extract and reconstruct 3D buildings in urban areas using airborne laser scanning data. Firstly all points in a building were divided into some groups by height difference. From segmented laser scanning data of irregularly distributed points we generalized and regularized building boundaries which better approximate the real boundaries. Then the roof points which are subject to the same groups were classified using pre-defined models by least squares fitting. Finally all parameters of the roof surfaces were determined and 3D building models were constructed. Some buildings with complex shapes were selected to test our presented algorithms. The results showed that proposed approach has good potential for reconstructing complex buildings in detail using only airborne laser scanning data.

Remote sensing images and interpretation for 'Reverse Difference' phenomenon of the marine sediments At the CaMau tongue (extreme South Vietnam - Mekong Basin)

  • Cuong, Nguyen Tien;Kwon, Seung-Joon;Kim, Yong-Il
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.682-686
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    • 2003
  • This paper is concerned with 'reverse difference' of marine sediments at the Camau tongue in the extreme south of Vietnam. We demonstrate the importance of remote sensing in geomorphology and marine geological application, using only visual evaluation and some data-processing techniques. In this paper, about 10,000 km$^2$ of the territorial water in the extreme south of Vietnam is being studied. We show that form and behavior of Mekong and its branch can be determined by visually interpreting remote sensing images and using ERDAS IMAGE 8.5 software. Besides, the 'reverse difference' phenomenon is explained by flows of Mekong river and its branches.

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Assessment of riparian buffers for reducing pollution according to land-cover pattern using RS and GIS

  • Ha, Sung-Ryong;Lee, Seung-Chul;Ko, Chang-Hwan;Jo, Yun-Won
    • Korean Journal of Remote Sensing
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    • v.22 no.5
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    • pp.445-449
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    • 2006
  • Diffuse pollution has been considering as a major source of the quality deterioration of water resources. The establishment of riparian vegetation strips or buffers along those areas of water bodies is used to reduce the threat of diffuse pollution. Remote sensing offers a means by which critical areas could be identified, so that subsequent action toward the establishment of riparian zones can be taken. On the behalf of KOMPSAT-2 satellite imagery as a high resolution spatial data, Landsat TM satellite data are used to aquire the land cover for the riparian buffers studied. This investigation aims to assess the riparian buffers established on the upper Geum river as a pollution mitigation. Through comparing the delineation of riparian buffer zones developed with the existing zones established by the government, we can find the critical distortion points of the existing riparian buffer zone.

An Analysis for Urban Change Using Satellite Images and GIS (GIS와 위성영상을 이용한 도시의 변화량 분석)

  • Shin, Ke-Jong;Yu, Young-Geol;Hwang, Eui-Jin
    • Journal of the Korean GEO-environmental Society
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    • v.6 no.4
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    • pp.73-80
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    • 2005
  • The domestic Remote Sensing field uses mainly Landsat TM image that is used to the monitoring of the wide area. In this study, it is analyzed the land cover change of rural and urban area by time series using satellite images and is proposed the vision for a urban balanced development. It execute an analysis for urban change which is a fundamental data of city planning through the integration of the spatial analysis technique of GIS and Remote Sensing using satellite data.

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Analysis of the Surface Urban Heat Island Changes according to NewTowns Development and Correlation with Urban Morphology (신도시 개발에 따른 표면 열섬현상 변화분석 및 도시 형태와의 상관관계)

  • Kyungil Lee
    • Korean Journal of Remote Sensing
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    • v.39 no.5_3
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    • pp.921-932
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    • 2023
  • Land cover change due to urban population concentration and urban expansion can cause various environmental problems such as urban heat islands. In particular, New towns are considered an appropriate study site to analyze changes in urban climate due to rapid urbanization in a short period. This study used Landsat satellite imagery to compare and analyze the land cover changes before and after the development of two new towns with different plans, and the resulting changes in surface urban heat island (SUHI) phenomena. Correlation analysis was also conducted between urban structural features that may affect the SUHI intensity. The results of the analysis confirm the rapid change in land cover as new town development progresses and the direct intensification of the SUHI phenomenon. This study confirms the differences in SUHI caused by different urban plans and suggests the need for three-dimensional urban planning to improve the thermal environment.

A Preliminary Analysis of the Impact of Urban Green Spaces on the Urban Heat Island Effect Using a Temperature Map

  • Myeong, Soo-Jeong
    • Korean Journal of Remote Sensing
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    • v.26 no.6
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    • pp.675-680
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    • 2010
  • Temperature is one of the main issues in climate change, and the urban heat island effect in highly developed urban areas is an important issue that we need to deal with. This study analyzed the extent of the cooling effects of urban green spaces. The study used a surface temperature map of Seoul. It found that the cooling effects of green space was observed within limited distances, although it varied a little depending on the parks investigated. The cooling effect distance ranged from 240m to 360m, averaging about 300m. It also found the size of an urban green space does not make much difference in cooling the surrounding areas. Although further investigation with diverse urban areas should be conducted on this matter, the results did imply that many small green spaces in the neighborhood are more effective than a single big green space in mitigating the heat island effects of cities.

Analyzing the correlation between urban forestry and surface temperature using Landsat TM data

  • Jo, Myung-Hee;Kim, Sung-Jae;Lee, Kwang-Jae
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.905-907
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    • 2003
  • In this study, the correlation between the heat island effect and the vegetation in Deagu Korea was performed through using Landsat TM data. the island effect, presents high temperature on air like island, is connected with correlation between the surface temperature and the temperature on the air. In this study, surface temperature was analyzed by detecting the change of urban forestry with remote sensing using the vegetation vitality statistics reference (ratio change of the Park greens in Daegu) the heat island effect not only brings the environment pollution but also brings serious problem such as the destruction of ecosystem to city as a whole. Jeff Luvall has studied to restrain the heat island effect by making urban forestry. Even though Daegu had been the serious high temperature urban area the current temperature of Daegu has been dropped. The correlation between the heat island effect and the vegetation index was analyzed by using satellite images.

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VARIOGRAM-BASED URBAN CHARACTERIZATION USING HIGH RESOLUTION SATELLITE IMAGERY

  • Yoo, Hee-Young;Lee, Ki-Won;Kwon, Byung-Doo
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.413-416
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    • 2006
  • As even small features can be classified as high resolution imagery, urban remote sensing is regarded as one of the important application fields in time of wide use of the commercialized high resolution satellite imageries. In this study, we have analyzed the variogram properties of high resolution imagery, which was obtained in urban area through the simple modeling and applied to the real image. Based on the grasped variogram characteristics, we have tried to decomposed two high-resolution imagery such as IKONOS and QuickBird reducing window size until the unique variogram that urban feature has come out and then been indexed. Modeling results will be used as the fundamental data for variographic analysis in urban area using high resolution imagery later on. Index map also can be used for determining urban complexity or land-use classification, because the index is influenced by the feature size.

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Application of Remote Sensing and GIS to the evaluation of riparian buffer zones

  • Ha, Sung-Ryong;Lee, Seung-Chul;Ko, Chang-Hwan;Seo, Se-Deok;Jo, Yun-Won
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.436-440
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    • 2006
  • Diffuse pollution has been considering as a major source of the quality deterioration of water resources. The establishment of riparian vegetation strips of buffers along those areas of water bodies is used to reduce the threat of diffuse pollution. Remote sensing offers a means by which critical areas could be identified, so that subsequent action toward the establishment of riparian zones can be taken. Even though the principal purpose of this research comes from the feasibility of the imagery of KOMPSAT-2 satellite, Landsat TM satellite data, which has 7 bands, are used to characterize the land cover for the study area on the behalf of KOMPSAT-2. This investigation focuses on the assessment of the existing riparian buffer zones for a portion of the upper Geum river watershed from the viewpoint of pollution mitigation by riparian vegetation strip establishment. Through comparing the delineation of riparian buffer zones developed with the existing zones established by the government, we can find the critical distortion points of the existing riparian buffer zone.

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