• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
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• pp.128-133
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• 1998

To assess the flood damages and to provide necessary information for preventing future catastrophe, it is necessary to appraise the inundated area with more accurate and rapid manner. This study attempts to evaluate the potential of satellite synthetic aperture radar (SAR) data for mapping of flood inundated area in southern part of Korea. JERS L-band SAR data obtained during the summer of 1997 were used to delineate the inundated areas. In addition, Landsat TM data were also used for analyzing the land cover condition before the flooding. Once the two data sets were co-registered, each data was separately classified. The water surface areas extracted from the SAR data and the land cover map generated using the TM data were overlaid to determine the flood inundated areas. Although manual interpretation of water surfaces from the SAR image seems rather simple, the computer classification of water body requires clear understanding of radar backscattering behavior on the earth's surfaces. It was found that some surface features, such as rice fields, runaway, and tidal flat, have very similar radar backscatter to water surface. Even though satellite SAR data have a great advantage over optical remote sensor data for obtaining imagery on time and would provide valuable information to analyze flood, it should be cautious to separate the exact areas of flood inundation from the similar features.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.556-559
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• 2007

The Urban Environmental Quality (UEQ) indicates a complex and various parameters resulting from both human and natural factors in an urban area. Vegetation, climate, air quality, and the urban infrastructure may interact to produce effects in an urban area. There are relationships among air pollution, vegetation, and degrading environmental the urban heat island (UHI) effect. This study investigates the application of multi-spectral remote sensing data from the Landsat ETM and TM sensors for the mapping of air quality and UHI intensity in Seoul from 2000 to 2006 in fine resolution (30m) using the emissivity-fusion method. The Haze Optimized Transform (HOT) correction approach has been adopted for atmospheric correction on all bands except thermal band. The general UHI values (${\Delta}(T_{urban}-T_{rural})$) are 8.45 (2000), 9.14 (2001), 8.61 (2002), and $8.41^{\circ}C$ (2006), respectively. Although the UHI values are similar during these years, the spatial coverage of "hot" surface temperature (>$24^{\circ}C$) significantly increased from 2000 to 2006 due to the rapid urban development. Furthermore, high correlations between vegetation index and land surface temperature were achieved with a correlation coefficients of 0.85 (2000), 0.81 (2001), 0.84(2002), and 0.89 (2006), respectively. Air quality is shown to be an important factor in the spatial variation of UEQ. Based on the quantifiable fine resolution satellite image parameters, UEQ can promote the understanding of the complex and dynamic factors controlling urban environment.

• 대한원격탐사학회지
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• 제20권5호
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• pp.289-305
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• 2004

Atmospheric correction of Landsat Visible and Near Infrared imagery (VIS/NIR) over aquatic environment is more demanding than over land because the signal from the water column is small and it carries immense information about biogeochemical variables in the ocean. This paper introduces two methods, a modified dark-pixel substraction technique (path--extraction) and our spectral shape matching method (SSMM), for the correction of the atmospheric effects in the Landsat VIS/NIR imagery in relation to the retrieval of meaningful information about the ocean color, especially from Case-2 waters (Morel and Prieur, 1977) around Korean peninsula. The results of these methods are compared with the classical atmospheric correction approaches based on the 6S radiative transfer model and standard SeaWiFS atmospheric algorithm. The atmospheric correction scheme using 6S radiative transfer code assumes a standard atmosphere with constant aerosol loading and a uniform, Lambertian surface, while the path-extraction assumes that the total radiance (L/sub TOA/) of a pixel of the black ocean (referred by Antoine and Morel, 1999) in a given image is considered as the path signal, which remains constant over, at least, the sub scene of Landsat VIS/NIR imagery. The assumption of SSMM is nearly similar, but it extracts the path signal from the L/sub TOA/ by matching-up the in-situ data of water-leaving radiance, for typical clear and turbid waters, and extrapolate it to be the spatially homogeneous contribution of the scattered signal after complex interaction of light with atmospheric aerosols and Raleigh particles, and direct reflection of light on the sea surface. The overall shape and magnitude of radiance or reflectance spectra of the atmospherically corrected Landsat VIS/NIR imagery by SSMM appears to have good agreement with the in-situ spectra collected for clear and turbid waters, while path-extraction over turbid waters though often reproduces in-situ spectra, but yields significant errors for clear waters due to the invalid assumption of zero water-leaving radiance for the black ocean pixels. Because of the standard atmosphere with constant aerosols and models adopted in 6S radiative transfer code, a large error is possible between the retrieved and in-situ spectra. The efficiency of spectral shape matching has also been explored, using SeaWiFS imagery for turbid waters and compared with that of the standard SeaWiFS atmospheric correction algorithm, which falls in highly turbid waters, due to the assumption that values of water-leaving radiance in the two NIR bands are negligible to enable retrieval of aerosol reflectance in the correction of ocean color imagery. Validation suggests that accurate the retrieval of water-leaving radiance is not feasible with the invalid assumption of the classical algorithms, but is feasible with SSMM.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2007년도 춘계학술발표회 논문집
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• pp.375-378
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• 2007

Kangwondo area is mountainous and landslide happens easily during the rainy period in summer time. Especially, when there is torrential downpour caused by the unusual weather change, there will be greater possibility to see landslide. Another reason behind landslide is the continuous forest fire in these several years. Since the surface of the earth has been changed by the fire, when rainfall comes, landslide just happens easily. Also, it is reported that landcover condition, excepted rainfall condition, is the most effect for determining landslide susceptibility area. In this study, it is determined a landslide vulnerable area and landcover information is extracted from four satellite image(Landsat TM), about the landslide vulnerable area, which is pictured for each year. And which distribution change is analyzed.

• 한국공간정보시스템학회:학술대회논문집
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• 한국공간정보시스템학회 2005년도 GIS/RS 공동 춘계학술대회
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• pp.249-253
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• 2005

인공위성 데이터를 이용한 원격탐사 기술과 지형공간정보시스템의 통합에 의한 도시에의 활용은 도시 계획뿐 만 아니라, 환경정비와 유지 관리 측면 등에서 중요한 역할을 하고 있다. 본 연구는 대상지역의 Landsat TM 영상자료를 이용하여 보정과정을 수행하고, GSIS 시스템의 NDVI(Normalized Difference Vegetation Index)식을 이용하여 식생지수를 추출하였다. 산출된 식생지수를 5개 등급으로 분류하여 비 식생지역과 식생이 활발한 지역을 구분하여 분석하였고, 인공위성 데이터의 밴드간 비연산 처리를 실시하여 식물의 건강상태를 나타내는 NDVI를 위성 데이터를 이용하여 추출함으로써, 시가지내의 녹지분포에 대한 시계열적 변화를 분석하였다. 이 결과 도심주변지역에 분포하는 낯은 구릉지에서 점차적으로 도시화가 이루어짐을 알 수 있었고, 전체 면적별 녹지분포가 높은 구릉지 및 산악지역의 3, 4, 5등급지역 면적 비율이 68.9%에서 37.2%로 감소한 것으로 나타났다.

• 한국공간정보시스템학회:학술대회논문집
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• 한국공간정보시스템학회 2007년도 GIS 공동춘계학술대회 논문집
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• pp.343-348
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• 2007

위성영상은 항공사진과 더불어 지표면의 변화를 신속하고 주기적으로 관찰할 수 있다는 장점을 가지고 있다. 이러한 장점뿐만 아니라 위성영상에 포함된 분광정보는 시간에 따른 지표면의 변화를 면밀하게 관찰이 가능하다. 이러한 장점들을 이용하여 현재 도시의 중추적인 교통수단으로서의 역할을 하고 있는 지하철 구간주변을 대상으로 시간에 따른 공간변화를 알아보았다. 지하철 건설전후의 구간을 대상으로 Landsat TM영상을 이용하여 토지이용변화 정도를, SPOT Panchromatic 영상을 이용하여 주거 및 상업지구의 변화정도를 위성영상을 통해 살펴보았다. 또한 부산에서 발간한 토지건축물 대장, 교통유발금부과대장을 통해 영상에서 나타난 건물들이 어떤 용도의 건물인지를 파악하고 부산교통공사에서 발간한 일반현황자료를 통하여 지하철이용의 현황과 이용행태를 주변 공간변화와 더불어 분석해보았다.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2006년도 춘계학술발표회 논문집
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• pp.159-163
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• 2006

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

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
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• pp.256-261
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• 1999

Global vegetation change is one of major global concerns. Remote sensing images provide an efficient and useful data source to estimate global vegetation covers, and a number of methods have been proposed to estimate them. Among them, the NDVI is one of the most popular indices, and it is_easy to calculate with simple image computing. However, this index is very much affected by the radiometric environment of sensing such as atmospheric conditions and the sun illumination angle. Therefore, it is not appropriate to apply the NDVI to investigate seasonal changes. This paper discusses these problems and proposes an alternative index, MODVI(Modified Vegetation Index), that is less affected by radiometric environment changes. An experiment was conducted to compare these two indices using temporal Landsat TM sub-scenes.

• 한국GIS학회:학술대회논문집
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• 한국GIS학회 2006년도 GIS/RS 공동춘계학술대회
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• pp.132-137
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• 2006

국토가 좁은 반면 산지가 많은 우리나라에서는 국가지리정보체계 관리 또는 산림자원의 개발과 보전에 대한 중요성이 매우 크다. 따라서 최근에는 산림지역을 대상으로 한 인공위성 영상의 활용 연구가 소개되고 있다. 위성영상은 지구자원의 탐사와 환경감시를 비롯하여 지형정보의 수집 및 분석 등 다양한 분야에서 높은 활용도를 보이고 있으며, 특히 직접 접근이 불가능하거나 까다로운 지역의 지형지물에 대한 다양한 정보의 취득이 가능하다는 장점을 지니고 있다. 광범위한 지역의 주기적인 정보획득이 가능한 인공위성 영상은 환경탐사분야에서 새로운 대안으로 받아들여지고 있으며, 산림분석에도 활용될 수 있다. 따라서, 본 연구에서는 식생분류에 유리한 다중분광센서를 가진 Landsat TM 위성영상을 이용하여 산림형태의 변화를 분석하였으며, 이를 주기적으로 모니터링 할 수 있도록 Web 상에 구축하였다. 이를 통하여 누구나 쉽게 넓은 대상지역 산림형태의 주기적 변화를 모니터링 할 수 있으며, 또한 현장조사 자료의 보완에도 효율적으로 사용될 수 있으리라 판단된다.

• 전자공학회논문지S
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• 제36S권4호
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• pp.38-44
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• 1999

본 논문에서는 웨이브릿 변환과 선택적 예측 벡터양자화를 이용한 인공위성 화상데이타 부호화 방법을 제안하였다. 이 방법에서는 대역내 중복성을 제거하기 위하여 각각의 대역을 웨이브릿 변환하고, 대역간 중복성을 제거하기 위해 에측하는 대역으로부터 생성된 임계치 지도를 이용하여 선택적 예측 벡터양자화를 행한다. 따라서 이 방법은 대역내 및 대역간 중복성을 효과적으로 제거하기 때문에 부호화 효율을 향상시킨다. 이 방법을 실제 Landsat TM 인공위성 화상데이타에 실험한 결과 기존의 방법에 비하여 부호화 효율이 향상됨을 확인하였다.