• 대한원격탐사학회지
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• 제19권5호
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• pp.363-370
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• 2003

This paper describes a rectification procedure that relies on a polynomial model derived from the imaging geometry without loss of accuracy. By using polynomial model, one can effectively eliminate the iterative process to find an image pixel corresponding to each output grid point. With the imaging geometry and ephemeris data, a geo-location polynomial can be constructed from grid points that are produced by solving three equations simultaneously. And, in order to correct the local distortions induced by the geometry and terrain height, a distortion model has been incorporated in the procedure, which is a function of incidence angle and height at each pixel position. With this function, it is straightforward to calculate the pixel displacement due to distortions and then pixels are assigned to the output grid by re-sampling the displaced pixels. Most of the necessary information for the construction of polynomial model is available in the leader file and some can be derived from others. For validation, sample images of ERS-l PRI and Radarsat-l SGF have been processed by the proposed method and evaluated against ground truth acquired from 1:25,000 topography maps.

• 대한원격탐사학회지
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• 제38권4호
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• pp.435-446
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• 2022

Identifying ship types is an important process to prevent illegal activities on territorial waters and assess marine traffic of Vessel Traffic Services Officer (VTSO). However, the Terrestrial Automatic Identification System (T-AIS) collected at the ground station has over 50% of vessels that do not contain the ship type information. Therefore, this study proposes a method of identifying ship types through the Random Forest Classifier (RFC) from dynamic and static data of AIS and V-Pass for one year and the Ulsan waters. With the hypothesis that six features, the speed, course, length, breadth, time, and location, enable to estimate of the ship type, four classification models were generated depending on length or breadth information since 81.9% of ships fully contain the two information. The accuracy were average 96.4% and 77.4% in the presence and absence of size information. The result shows that the proposed method is adaptable to identifying ship types.

• 대한원격탐사학회지
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• 제38권4호
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• pp.365-374
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• 2022

Mining activity causes environmental pollution and geological hazards such as ground subsidence or landslide of which continuous monitoring is necessary. In this study, the activity on the Fushun West Open-Pit Mine (FWOPM), one of the largest open-pit coal mines in Asia located in Fushun, Liaoning Province, China, was analyzed by using a time-series Sentinel-1 InSAR coherence dataset. By using the difference between the two Digital Elevation Models (DEM) of the area, it was possible to confirm that there was a stockpiling activity in the western area of the FWOPM while excavation activity in the eastern area. By using RGB composite images using the yearly-averaged InSAR coherence images, the activity of the mine was confirmed by period, which was confirmed by Google Earth optical images. As a result, it was possible to confirm three landslides and the related activities on the northwest slope and the dumping activity on the west slope of FWOPM.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.496-499
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• 2007

The COMS ground segment will operate the geostationary satellite continuously 24h/7days and deliver processed data to end-users with respect to the predefined schedule without delay. For reliable operation, each COMS ground center has internally dual-configuration for critical systems but impossible to every components. Any unexpected failure or regular maintenance to the single configured antenna system may lead the interruption of COMS service and operation. The natural disaster or external attack can destroy one ground center and the operation will be stopped. Therefore COMS program implements backup system remotely located in other centers. Even considering foreign geostationary systems, it's the best solution guaranteeing consistent system operation against internal failure or external disaster.

• 대한원격탐사학회지
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• 제22권2호
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• pp.141-151
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• 2006

태양광을 광원으로 하고 천정방향을 포함한 다양한 고도각을 이용하는 자외선/가시광선영역에서의 흡수분광학이 최근에 지상용 대기원격 측정에 개발되어오고 있다. 이를 이용하여 지표부근에 존재하는 대기 미량 물질의 공간적 분포가 유추될 수 있다. 대기질 측정기술 중 하나인 MAX-DOAS (Multi-axis Differential Optical Absorption Spectroscopy) 기술은 광원으로서 태양산란광을 이용하고, 다양한 고도각에서 태양산란광을 기록하고 분석을 통하여 대기 중 미량 물질을 측정한다. 광주과학기술원 환경모니터링 신기술 연구센터에서 개발된 MAX-DOAS 시스템은 9004년 1월, 5월, 10월에 각각 도시대기, 화산플룸, 화력발전소 플룸의 측정에 적용되었다. 각각의 경우에 $SO_2,\;NO_2,\;BrO,\;O_4$를 정량분석하기 위하여 기록된 MAX-DOAS 스펙트럼은 자외선/가시광선 영역에서의 고유 흡수스펙트럼을 이용한 DOAS 기술을 이용하여 분석 되었다. 그 결과는 Slant Column Density (SCD)로 표현되었다. 플룸 측정의 경우에서는 플룸 속에 포함된 $NO_2,\;SO_2$의 공간적 분포를 파악하기 위하여 플룸의 진행방향과 수직적인 방향에서 MAX-DOAS 스캔이 이루어졌다. 이를 통하여 얻은 단면적을 토대로 $SO_2,\;NO_2$ 농도가 계산되었다. 화산플룸에서 $SO_2$는 580ppbv, 화력발전소 플룸에서 $NO_2$는 337ppbv, $SO_2$는 227ppbv 로 계산되었다.

• 대한원격탐사학회지
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• 제35권5_2호
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• pp.763-772
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• 2019

전 지구를 주기적으로 관측할 수 있는 고해상 위성의 개발로 국가 재난 전조 모니터링에서 신속한 복구계획 수립에 이르기 까지 원격탐사를 활용한 국가 재난관리 활용 분야는 점차 확대되고 있다. 국립재난안전연구원에서는 태풍 풍수해, 가뭄, 폭설, 지반변위, 열섬 분석, 강우추정 모델 개발 등 위성을 활용한 다양한 재난관리 기술을 개발하고 이를 재난관리 현업에 활용하고 있다. 촌각을 다투는 재난상황에서 적시적인 위성영상 수급 문제가 도전적인 이슈이긴 하나, 국내외 우주개발기구와 재난협의체가 주도하는 전 지구적인 재난에 공동 대응을 위한 국제협력 프로그램 참여를 통해 해소하고자 하고 있다. 이번 특별호에서는 전 지구적인 이상기후와 기후변화로 급변하고 있는 한반도 주변의 재해 재난 사고를 원격으로 조기에 감지하고 모니터링 할 수 있는 인공위성기반의 재해 재난 모니터링 기술개발 현황과 재난 현장에 최대한 접근하여 고정밀의 재난정보수집하는 첨단장비기반의 고정밀 재난정보 센싱 기술개발 현황 등 국립재난안전연구원의 원격탐사와 첨단장비를 활용한 과학적인 재해 재난 사고 관리 기술을 소개하였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.728-731
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• 2006

Ground subsidence near abandoned underground coal mines has become a serious social problem in Korea. The purpose of this study is to perform a comparative analysis between the ground subsidence area and the electrical resistivity measured by field survey at Samcheok City. A raster database composed of ground subsidence areas and electrical resistivity data was constructed for GIS. To analyze correlation between the two constructed raster datasets, we used a frequency ratio model. The results show that low and high electrical resistivity anomaly zones coincide with the existing subsidence areas. We infer that the high anomaly zone means saturated and low anomaly zone means vacant. It suggests that electrical resistivity might be a useful factor for analyzing ground subsidence hazard zone.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.500-503
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• 2007

During the COMS system level test, the RF compatibility will be performed in order to verify that there is no issue in RF interface between satellite and COMS ground station, namely SOC (Satellite Operation Center) before the launch. As used for KOMPSAT1, the RF coaxial cable was chosen to be used to connect satellite and SOC with various advantages as compared with ground antennas. As the preparation step, RF cable and required multiplexer were tested in advance. This paper suggests the way for the RF compatibility tests between the satellite and the SOC over RF cable interface and presents the estimated level diagram as the signal power analysis result.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1058-1060
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• 2003

A ground control point (GCP) is a point on the surface of Earth where image coord inates and map coordinates can be identified. The GCP is useful for the geometric correction of systematic and unsystematic errors usually contained in a remotely sensed data. Especially in case of synthetic aperture radar (SAR) data, it has serious geometric distortions caused by inherent side looking geometry. In addition, SAR images are usually severely corrupted by speckle noises so that it is difficult to identify ground control points. We developed a ground point extraction algorithm that has an improved capability. An application of radargrammetry to Daejon area in Korea was studied to acquire the geometric information. For the ground control point extraction algorithm, an ERS SAR data with precise Delft orbit information and rough digital elevation model (DEM) were used. We analyze the accuracy of the results from our algorithm by using digital map and GPS survey data.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.649-652
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• 2005

In this paper we present a detail approach of the determination of IFOV (Instantaneous Field of View) of high-resolution (l m) panchromatic satellite image over test site. IFOV is the representative measurements as the determination of the spatial resolution in remote sensed imaging system. It can be defined as some area on the ground with the particular altitude when the satellite acquires the image at any given time. Especially, spatial resolution of passive sensors primarily depends on their IFOV. The determination of IFOV goes through simple steps of procedure as followings: Firstly, the GSD (Ground Sample Distance) should be computed at each point on the geometrically corrected image. Then, The GSD is converted into the IFOV. So we are going to explain our test procedures and results.