• Title/Summary/Keyword: Landsat 영상

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Comparison of Digital Number Distribution Changes of Each Class according to Atmospheric Correction in LANDSAT-5 TM (LANDSAT-5 TM 영상의 대기보정에 따른 클래스별 화소값 분포 변화 비교)

  • Jung, Tae-Woong;Eo, Yang-Dam;Jin, Tailie;Lim, Sang-Boem;Park, Doo-Youl;Park, Hwang-Soo;Piao, Minghe;Park, Wan-Yong
    • Korean Journal of Remote Sensing
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    • v.25 no.1
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    • pp.11-20
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    • 2009
  • Due to increasing frequency of yellow dust, not to mention high rate of precipitation and cloud formation in summer season of Korea, atmospheric correction of satellite remote sensing is necessary. This research analyzes the effect of atmospheric correction has on imagery classification by comparing DN distribution before and after atmospheric correction. The image used in the research is LANDSAT-5 TM. As for atmospheric correction module, commercial product ATCOR, FLAASH as well as COST model released on the internet, were used. The result of experiment shows that class separability increased in building areas.

Analysis of Temperature Change by Forest Growth for Mitigation of the Urban Heat Island (도시열섬 완화를 위한 녹지증가에 따른 온도변화 분석)

  • Yun, Hee Cheon;Kim, Min Gyu;Jung, Kap Yong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.31 no.2
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    • pp.143-150
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    • 2013
  • Recently, environmental issues such as climate warming, ozone layer depletion, reduction of tropical forests and desertification are emerging as global environmental problems beyond national problems. And international attention and effort have been carried out in many ways to solve these problems. In this study, the growth of green was calculated quantitatively using the technique of remote sensing and temperature change was figured out through temperature extraction in the city. The land-cover changes and thermal changes for research areas were analyzed using Landsat TM images on May 2002 and May 2009. Surface temperature distribution was calculated using spectral degree of brightness of Band 6 that was Landsat TM thermal infrared sensor to extract the ground surface temperature in the city. As a result of research, the area of urban green belt was increased by $2.87km^2$ and the ground surface temperature decreased by $0.6^{\circ}C{\sim}0.8^{\circ}C$ before and after tree planting projects. Henceforth, if the additional study about temperature of downtown is performed based on remote sensing and measurement data, it will contribute to solve the problems about the urban environment.

Temperature Change Analysis for Land Use Zoning Using Landsat Satellite Imagery (Landsat위성영상에 의한 용도지역 온도변화분석)

  • Jung, Gil-Sub;Koo, Seul;Yoo, Hwan-Hee
    • Journal of Korean Society for Geospatial Information Science
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    • v.19 no.2
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    • pp.55-61
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    • 2011
  • The land use has been changed artificially and caused the result of temperature increase of city compared with the outside of city or region of park and forest. The purpose of this research is to analyze the change of the urban surface temperature with land use zoning in Jinju using Landsat TM/$ETM^+$ imagery and to provide the correlation between NDVI(Normalized Difference Vegetation Index) and urban surface temperature change. The results presented that the spatial distribution of urban surface temperature was depending on the change of NDVI values on land use zoning. Considering to the average temperature by land use zoning, industrial area was the highest temperature but green area was the lowest temperature. Also as a result of comparing the correlation between surface temperature and NDVI, the green and residential area had higher correlation values than the commercial and industrial area. These results will be played a part as one of the major factors for implementing the sustainable urban planning considering the urban heat island effect problem.

Urbanization Analysis of Major City in North Korea Using Landsat Imagery (Landsat 영상을 활용한 북한 주요도시의 도시화 지수 분석)

  • Jun Hyun, Kim
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.33 no.4
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    • pp.277-286
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    • 2015
  • This study calculated the NDVI and the NDBI of the land-use change in major cities at North Korea through Landsat imagery, and analyzed the spatiality(LISA) with difference discretization of the UI index. As a result of the research, we could identify that the degree of urbanization has been increased in both Gaesung and Pyeongyang, but showed opposite spatial tendency to each other. The urban index of Pyeongyang, a nucleus district of North Korea, has been progressed quicker than Gaesung since 1994, while the urbanization development was being progressed also in general, as it expanded from the existing downtown area. On the other hand, the urbanization took place intensively at one region in Gaesung by developing the vegetation area that forest transfers into a built-up area, which has been judged from the great dynamic range of NDVI values. In conclusion, it is possible to extract necessary data for understanding the degree of urbanization and spatial characteristics of North Korea through the UI and the LISA analysis that are considered to propose useful methodology in investigating changes in North Korean cities and political levearage.

Active Fire Detection Using Landsat 8 OLI Images: A Case of 2019 Australia Fires (Landsat 8 OLI 영상을 이용한 산불탐지: 2019년 호주 산불을 사례로)

  • Kim, Nari;Lee, Yangwon
    • Korean Journal of Remote Sensing
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    • v.36 no.5_1
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    • pp.775-784
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    • 2020
  • Recent global warming and anthropogenic activities have caused more frequent and massive wildfires with longer durations and more significant damages. MODIS has been monitoring global wildfires for almost 20 years, and GK2A and Himawari-8 are observing the wildfires in East Asia 144 times a day. However, the spatial resolution of 1 to 2 km is not sufficient for the detection of small and medium-size active fires, and therefore the studies on the active fire detection using high-resolution images are essential. However, there is no official product for the high-resolution active fire detection. Hence, we implemented the active fire detection algorithm of Landsat 8 and carried out a high-resolution-based detection of active fires in Australia in 2019, followed by the comparisons with the products of Himawari-8 and MODIS. Regarding the intense fires, the three satellites showed similar results, whereas the weak igniting and extinguishing fires or the fires in narrow areas were detected by only Landsat 8 with a 30m resolution. Small-sized fires, which are the majority in Korea, can be detected by the high-resolution satellites such as Landsat 8, Sentinel-2, Kompsat-3A, and the forthcoming Kompsat-7. Also, a comprehensive analysis together with the geostationary satellites in East Asia such as GK2A, Himawari-8, and Fengyun-3 will help the interoperability and the improvement of spatial and temporal resolutions.

Prospects for Utilizing KITSAT-3 Imaging (우리별 3호 위성영상 처리 및 분석)

  • Jong-In Kim;young-cho Lim;mi-gyung Cho;jong-in Kim
    • Proceedings of the KSRS Conference
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    • 1999.11a
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    • pp.54-59
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    • 1999
  • The KITSAT-3, launched on May 26th of 1999, is equiped with a high-resolution earth-watch sensor that has spectral bands similar to that of the SPOT. In this paper, the primary discussion is on Investigation of possible application of images acquired from this sensor The secondary discussion is on the comparison of the images with those of Landsat TM and SPOT.

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Comparison between supervised and unsupervised land cover classification using satellite image (인공위성 영상을 이용한 토지피복의 감독 분류 및 무감독 분류 비교)

  • Han, Seung-Jae;Choi, Min-Ha
    • Proceedings of the Korea Water Resources Association Conference
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    • 2011.05a
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    • pp.355-355
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    • 2011
  • 토지피복의 분류는 토지표면의 물리적인 지표면의 상태를 나타내는 자료로 환경, 행정, 수자원, 재해 등 다방면으로 이용되고 있다. 특히 수자원과 관련하여 식생의 증산과 토양의 증발을 통칭하는 증발산과 유출, 토양수분 등과 연관되어 있다. 광범위한 토지피복의 산정에는 경제성 및 주기성 등의 장점으로 인하여 인공위성 영상을 이용하는 기법이 적합하다. 위성영상분류법은 훈련지역의 선정 여부에 따라 감독분류와 무감독 분류로 나누어지며 각각의 알고리즘의 특성에 따라 더욱 세분화된다. 본 연구에서는 Landsat-TM (Thematic Mapper) 영상을 이용하여 감독 분류와 무감독 분류를 각각 적용하여 한강유역의 토지피복을 수역, 시가, 나지 습지, 초지, 산림, 농지의 7가지 부분으로 대분류로 산정하고 비교하였다. 두 경우의 정확도는 각각 91.6%, 90.9%의 비슷한 정확도를 나타내었으며, 세부적으로 우리나라의 대부분의 면적에 분포하는 산림, 농지, 시가, 수역의 정확도가 높게 나타났다. 또한 각 항목별로 정확도를 비교하였을 때 감독분류가 무감독분류에 비해 다소 정확한 것을 확인할 수 있었다. 추후 외부자료를 도입하면 비교적 낮은 정확도를 나타낸 초지, 습지, 나지의 정확도를 보완할 수 있을 것이다.

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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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A Study on the Detection of Land Cover Changes in Southern Han River Using Landsat Images (인공위성 영상을 이용한 남한강 유역의 토지피복 변화량 검출)

  • 윤홍식;조재명;안영준
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.20 no.2
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    • pp.145-153
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    • 2002
  • Reforming land is an important foundation for benefit of society as well as national development. A correct investigation and information acquirement as to land must go first to establish land management and plan. Land investigation by remote sensing is one of the most reasonable methods that doesn't need lots of time and manpower. In this study, Image classification on land use from Landsat data was carried out, which were respectively in 1980, 1985, 1990, 1995 and 2000, covering southern Han river and then land use changes were detected. In addition, an available information was reported, which could be used in the control of southern Han river. As a result, there is an obvious change in land use, especially the increase of water and decrease of forest and agriculture. Those are caused by the industrialization and the construction of dam.

An Efficient Method to Estimate Land Surface Temperature Difference (LSTD) Using Landsat Satellite Images (Landsat 위성영상을 이용한 지표온도차 추정기법)

  • Park, Sung-Hwan;Jung, Hyung-Sup;Shin, Han-Sup
    • Korean Journal of Remote Sensing
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    • v.29 no.2
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    • pp.197-207
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    • 2013
  • Difficulties of emissivity determination and atmospheric correction degrade the estimation accuracy of land surface temperature (LST). That is, since the emissivity determination of land surface material and the correction of atmospheric effect are not perfect, it is very difficult to estimate the precise LST from a thermal infrared image such as Landsat TM and ETM+, ASTER, etc. In this study, we propose an efficient method to estimate land surface temperature difference (LSTD) rather than LST from Landsat thermal band images. This method is based on the assumptions that 1) atmospheric effects are same over a image and 2) the emissivity of vegetation region is 0.99. To validate the performance of the proposed method, error sensitive analysis according to error variations of reference land surface temperature and the water vapor is performed. The results show that the estimated LSTD have respectively the errors of ${\pm}0.06K$, ${\pm}0.15K$ and ${\pm}0.30K$ when the water vapor error of ${\pm}0.302g/cm^2$ and the radiance differences of 0.2, 0.5 and $1.0Wm^{-2}sr^{-1}{\mu}m$ are considered. And also the errors of the LSTD estimation are respectively ${\pm}0.037K$, ${\pm}0.089K$, ${\pm}0.168K$ in the reference land surface temperature error of ${\pm}2.41K$. Therefore, the proposed method enables to estimate the LSTD with the accuracy of less than 0.5K.