• Journal of the Korean Association of Geographic Information Studies
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• v.4 no.4
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• pp.72-78
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• 2001

In this study, high spatial resolution of IKONOS 1m image and Red(0.63~0.69) band, NIR(0.76~0.90) band in 4m image, which are the same wavelength range as Landsat TM band 3, 4, were used for extraction of the front areas of B. Xylophilus in Geuje island where is located in southern part of Korea. Moreover, since they have higher spatial resolutions than Landsat TM, they have been used for lots of studies in the field of forest and vegetation. In the results, it was validated by GPS field survey, spectral histogram analysis of IKONOS NIR band was significant available method for extracting the front areas of B. Xylophilus. In this study, 15 points were verified as real damaged trees of 22 sample points extracted from GPS field survey. This study was not only extracted the damaged trees by B. Xylophilus but also suggested the possibility of using IKONOS images for the study on the forest damages by any disease and insect pests.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.1
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• pp.1-7
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• 2005

We propose an effective Landsat TM image compression method using the classified bidirectional prediction (CBP), the classified KLT and the SPIHT. The SPIHT is used to exploit the spatial redundancy of feature bands selected in the visible range and the infrared range separately. Regions of the prediction bands are classified into three classes in the wavelet domain, and then the CBP is performed to exploit the spectral redundancy. Residual bands that consist of difference values between the original band and the predicted band are decorrelated by the spectral KLT Finally, the three dimensional (3-D) SPIHT is used to encode the decorrelated coefficients. Experiment results show that the proposed method reconstructs higher quality Landsat TM image than conventional methods at the same bit rate.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.5
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• pp.77-83
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• 2008

In this study, land cover classification and NDVI evaluation for hazard mitigation precaution are carried out in surrounding areas of Yeongi-gun, Chungcheongnam-do ($132\;km^2$) where a project for multi-functional administrative city is promoted by government. Image acquired from KOMPSAT 2, LANDSAT and ASTER is utilized and comparative evaluation on limitation in classification based on resolution was carried out. The area mainly consists of arable land including mountains, rice fields, ordinary fields, etc thus special attention was paid to the classification of rice fields and ordinary fields. For the classification of image acquired from KOMPSAT 2, segmentation technique for classification of high-resolution image was applied. To evaluate the accuracy of the classification, field investigation was conducted to examine the sample and it was compared with the land usage and classification of land category in land ledger of Korea. Acquired results were made into theme map in shape file format and it would be of great help in decision making of policy for the future-oriented development plan of multi-functional administrative city.

• Journal of Korea Water Resources Association
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• v.36 no.6
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• pp.999-1012
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• 2003

The objective of this study is to test the applicability of CN values suggested using land cover and treatment classification of satellite image. Applicability test is based on the comparison of observed effective rainfall and computed one. The 3 case study areas, where are the upstream of Gyeongan stage station, the upstream of Baekokpo stage station Pyungchang River basin, and the upstream of Koesan Dam, are selected to test the proposed CN values and the hydrologic and meteorologic data, Landsat-7 ETM of 2000, soil map of 1:50,000 are collected for the selected areas. The results show that the computed CN values for three study cases are 71, 63, 66, respectively, and the errors between observed and computed effective rainfall are within about 30%. It can be concluded that the proposed CN values from this study for land cover and treatment classification of satellite image not only provides more accurate results for the computation of effective rainfall, but also suggest the objective CN values and effective rainfall.

• Korean Journal of Remote Sensing
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• v.5 no.1
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• pp.1-12
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• 1989

The objective of this study is to develop the application techniques, such as geometrical correction, image overlapping etc., of LANDSAT Thematic Mapper image data especially useful to the geomorphological study of tidal flats. The developed processing techniques were applied to the Kum river estuary. The results of this study are as follows. 1) According to the analysis of the distribution and topographical profiles of the tidal flats, the geomorphological characteristics of the study area seem to be different depending on their location. 2) Even though the geomorphological changes were not always observable on the satellite images, several areas of undoubtful short-term deposition could be detected on the analytical map-image which compares two different situations of tidal flats. 3) Even though a further ditailed study is necessary, the distribution and dispersal patterns of suspended materials and sea surface temperature distribution patterns due to tidal and other meteorological conditions were analyzed by LANDSAT TM channel 3 and 6.

• 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.

• Journal of the Korean earth science society
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• v.25 no.8
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• pp.754-763
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• 2004

This study was aimed to examine the Landsat Enhanced Thematic Mapper Plus (ETM+) index, which matches well with the field survey data in the wildfire area of Gangneung, Gangweon Province, Korea. In the wildfire area NDVI (Normalized Difference Vegetation Index), SAVI (Soil Adjusted Vegetation Index), and Tasseled Cap Transformation Index (Brightness, Wetness, Greenness) were compared with field survey data. NDVI and SAVI were very useful in detecting the difference between the wildfire and non-wildfire area, but not so in classify the soil types in the wildfire area. The soil plane based on the Tasseled Cap Transformation showed a better result in classifying the soil types in the wildfire areas than NDVI and SAVI, and corresponded well with field survey data. Using a linear function based on greenness and wetness in the Tasseled Cap Transformation is expected to provide a more efficient and quicker method to classify wildfire areas.

• Journal of Korean Society for Geospatial Information Science
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• v.13 no.2 s.32
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• pp.13-20
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• 2005

Upon the request of balanced development of the country and making inroads into the continent of China the development of the west coast was begun in the late 1980s, which has been being continued till recently under the blueprint of making the western part of the capital region to be the hub of northeastern Asia. As more lively development is expected to continue in the area, there are many occurrences of change in topology and terrain in the west coast. This study was done to detect the topographic and terrain change of the vicinity of the west coast. To make the basic map of the change in topology and terrain, the mosaic images were made using landsat images. The accuracy of the images was examined by comparing them with GCP through 1:25,000's digital map. After that, among the resultant images of the 1970s and 2000s, those of Sihwa, Hwaong and Ansan, the lands reclaimed by drainage were compared to observe the change in the area. From the results, it was concluded that, in case of the land the topological change was not so big due to the development in the reclaimed land or the bare land, and the area of agriculture and downtown increased, the drainage and bare land area decreased by comparing the change of land use.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.2
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• pp.133-142
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• 2014

Landsat is one of the popular satellites for observing land surface that is used in various areas including monitoring, detecting and classifying changes in land surface. However, shades, which cloud itself and its shadow, interrupted often clear observation and analysis of ground surface. For this reason, the process of removing shades and restoring original ground surfaces are critical for geospatial users. This study is planned to recommend a methodology for more accurate and clear images of Landsat-8 sensor, which provided two additional bands of costal/aerosol and cirrus. In fact, those bands are known as functioned effectively in detecting and restoring shades. Otsu's thresholding technique to detect clouds, we replaced those detective shades by using experimental and reference images. In accurate assessment, the overall accuracy and kappa coefficients were about 85% and 0.7128, respectively. This indicates that the proposed technique is effective for recovering the original land surface.

• Korean Journal of Remote Sensing
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• v.22 no.2
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• pp.87-99
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• 2006

The Median Resolution Sensors (MRSs) for land observation such as Landsat-ETM+ and SPOT-HRV are more effective than Ocean Color Sensors (OCSs) for studying of detailed ecological and biogeochemical components of the coastal waters. In this study, we developed suspended sediment algorithm for Landsat TM/ETM+ by considering the spectral response curve of each band. To estimate suspended sediment concentration (SS) from satellite image data, there are two difference types of algorithms, that are derived for enhancing the accuracy of SS from Landsat imagery. Both empirical and remote sensing reflectance model (hereafter referred to as $R_{rs}$ model) are used here. This study tried to compare two algorithm, and verified using in situ SS data. It was found that the empirical SS algorithm using band 2 produced the best result. $R_{rs}$ model-based SS algorithm estimated higher values than empirical SS algorithm. In this study we used $R_{rs}$ model developed by Ahn (2000) focused on the Mediterranean coastal area. That's owing to the difference of oceanic characteristics between Mediterranean and Korean coastal area. In the future we will improve that $R_{rs}$ model for the Korean coastal area, then the result will be advanced.