• 대한원격탐사학회지
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• 제38권6_1호
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• pp.1035-1046
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• 2022

이 연구에서는 토지 피복 분류를 위한 다중 해상도 자료 융합의 적용성을 평가하였다. 여기서 다중 해상도 자료 융합 모델로는 spatial time-series geostatistical deconvolution/fusion model (STGDFM)을 적용하였다. 연구 지역은 미국 Iowa 주의 일부 농경 지역으로 선정하였으며, 대상 지역의 규모를 고려해 다중 해상도 자료 융합의 입력 자료로 Moderate Resolution Imaging Spectroradiometer (MODIS) 및 Landsat 영상을 사용하였다. 이를 바탕으로 STGDFM 적용해 Landsat 영상이 결측된 시기에서 가상의 Landsat 영상을 생성하였다. 그리고 획득한 Landsat 영상과 함께 STGDFM의 융합 결과를 입력 자료로 사용해 토지 피복 분류를 수행하였다. 특히 다중 해상도 자료 융합의 적용성 평가를 위해 획득한 Landsat 영상만을 이용한 분류 결과와 Landsat 영상 및 융합 결과를 모두 이용한 분류 결과를 비교 평가하였다. 그 결과, Landsat 영상만을 이용한 분류 결과에서는 대상 지역의 주요 토지 피복인 옥수수와 콩 재배지에서 혼재 양상이 두드러지게 나타났다. 또한 건초 및 곡물 지역과 초지 지역 등 식생 피복 간의 혼재 양상도 큰 것으로 나타났다. 반면 Landsat 영상 및 융합 결과를 이용한 분류 결과에서는 옥수수와 콩 재배지의 혼재 양상과 식생 피복 간의 혼재 양상이 크게 완화되었다. 이러한 영향으로 Landsat 영상 및 융합 결과를 이용한 분류 결과에서 분류 정확도가 약 20%p 향상되었다. 이는 STGDFM을 통해 MODIS 영상이 갖는 시계열 분광 정보를 융합 결과에 반영하면서 Landsat 영상의 결측을 보완할 수 있었고, 이러한 시계열 분광 정보가 분류 과정에 결합되면서 오분류를 크게 줄일 수 있었던 것으로 판단된다. 본 연구 결과를 통해 토지 피복 분류에 다중 해상도 자료 융합이 효과적으로 적용될 수 있음을 확인하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1999년도 제14차 학술회의논문집
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• pp.29-32
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• 1999

Korea Multi-Purpose SATellite(KOMPSAT) is scheduled to be launched by TAURUS launch vehicle in November, 1999. Tracking, Telemetry and Command(TT&C) operation and the flight dynamics support should be performed for the successful Launch and Early Orbit Phase(LEOP) operation. After the first contact of the KOMPSAT spacecraft, initial orbit determination using ground based tracking data should be performed for the acquisition of the orbit. Although the KOMPSAT is planned to be directly inserted into the Sun- synchronous orbit of 685 km altitude, the orbit maneuvers are required fur the correction of the launch vehicle dispersion. Flight dynamics support such as orbit determination and maneuver planning will be performed by using KOMPSAT Mission Analysis and Planning Subsystem(MAPS) in KOMPSAT Mission Control Element(MCE). The KOMPSAT MAPS have been jointly developed by Electronics and Telecommunications Research Institute(ETRI) and Hyundai Space & Aircraft Company(HYSA). The KOMPSAT MCE was installed in Korea Aerospace Research Institute(KARI) site for the KOMPSAT operation. In this paper, the orbit determination and maneuver planning are introduced and simulated for the KOMPSAT spacecraft in LEOP operation. Initial orbit determination using short arc tracking data and definitive orbit determination using multiple passes tracking data are performed. Orbit maneuvers for the altitude correction and inclination correction are planned for achieving the final mission orbit of the KOMPSAT.

• ETRI Journal
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• 제26권3호
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• pp.218-228
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• 2004

Using stereo images with ephemeris data from the Korea Multi-Purpose Satellite-1 electro-optical camera (KOMPSAT-1 EOC), we performed geometric modeling for three-dimensional (3-D) positioning and evaluated its accuracy. In the geometric modeling procedures, we used ephemeris data included in the image header file to calculate the orbital parameters, sensor attitudes, and satellite position. An inconsistency between the time information of the ephemeris data and that of the center of the image frame was found, which caused a significant offset in satellite position. This time inconsistency was successfully adjusted. We modeled the actual satellite positions of the left and right images using only two ground control points and then achieved 3-D positioning using the KOMPSAT-1 EOC stereo images. The results show that the positioning accuracy was about 12-17 m root mean square error (RMSE) when 6.6 m resolution EOC stereo images were used along with the ephemeris data and only two ground control points (GCPs). If more accurate ephemeris data are provided in the near future, then a more accurate 3-D positioning will also be realized using only the EOC stereo images with ephemeris data and without the need for any GCPs.

• 한국컴퓨터정보학회논문지
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• 제17권3호
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• pp.85-93
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• 2012

본 논문에서는 MF-TDMA (Multi Frequency-Time Division Multiple Access) DAMA (Demand-Assigned Multiple Access) 방식을 사용하는 위성 망에서 지상 단말이 네트워크 제어기에게 자원을 요청할 때, 자신에게 유입되어지는 트래픽에 대한 이전 정보(History) 즉, 트래픽 발생 패턴이나 트래픽 종류 등을 바탕으로 자원을 요청하고, 네트워크 제어기는 지상 단말들이 이전에 요청했던 정보(History)를 바탕으로 보다 효율적으로 위성 자원을 할당하여 위성 망 자원 할당 시간의 지연으로 인한 다량의 데이터 폐기를 최대한 억제하기 위한 MF-TDMA DAMA 방식 위성 시스템을 설계하였다. 미군의 전략적 군사 정보망 (Warfighter Information Network-Tactical, WIN-T) 커뮤니티에서는 L-3 Linkabit 다중 주파수-시간 분할 다중 접속 (MF-TDMA) 요청에 의해 할당되어지는 다중 접속 (DAMA) 네트워크 중심 파형 (Network Centric Waveform, NCW)을 full-mesh IP over SHF 위성 통신을 위한 네트워크 표준으로 선택하였다. MF-TDMA 위성 망에서는 네트워크 제어기(Network Controller, NC)가 최대 255개의 지상 단말들 (Earth Terminals, ETs)의 주기적인 자원요청에 대하여 동적으로 위성 망 자원을 할당하여 단말들 간의 통신을 가능하도록 한다.

• 대한원격탐사학회지
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• 제20권5호
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• pp.337-351
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• 2004

Our laboratory originally developed the compact, multi-spectral, automatic aerial photographic system PKNU3 to allow greater flexibility in geological and environmental data collection. We are currently developing the PKNU3 system, which consists of a color-infrared spectral camera capable of simultaneous photography in the visible and near-infrared bands; a thermal infrared camera; two computers, each with an 80-gigabyte memory capacity for storing images; an MPEG board that can compress and transfer data to the computers in real-time; and the capability of using a helicopter platform. Before actual aerial photographic testing of the PKNU3, we experimented with each sensor. We analyzed the lens distortion, the sensitivity of the CCD in each band, and the thermal response of the thermal infrared sensor before the aerial photographing. As of September 2004, the PKNU3 development schedule has reached the second phase of testing. As the result of two aerial photographic tests, R, G, B and IR images were taken simultaneously; and images with an overlap rate of 70% using the automatic 1-s interval data recording time could be obtained by PKNU3. Further study is warranted to enhance the system with the addition of gyroscopic and IMU units. We evaluated the PKNU 3 system as a method of environmental remote sensing by comparing each chlorophyll image derived from PKNU 3 photographs. This appraisement was backed up with existing study that resulted in a modest improvement in the linear fit between the measures of chlorophyll and the RVI, NDVI and SAVI images stem from photographs taken by Duncantech MS 3100 which has same spectral configuration with MS 4000 used in PKNU3 system.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.95-97
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• 2005

Communication, Ocean, and Meteorological Satellite (COMS) to be launched in year 2008 will be the first Korean multi-purpose geostationary satellite aiming at three major missions, i.e.: communication, ocean, and meteorological applications. The development of systems for the meteorological mission sponsored by the Korea Meteorological Administration (KMA) consists of payloads, ground system, and data processing system. The program called COMS Meteorological Data Processing System (CMDPS) has been initiated for the development of data processing system. The primary objective ofCMDPS is to derive the level-2 environmental products from geo-Iocated and calibrated level 1.5 COMS data. Preliminary design for the level-2 data processing system consists of 16 baseline products and will be refined by end of 3rd project year. Also considered for the development are the necessary initial information such as land use and digital elevation map, algorithms for the vicarious calibration and procedures for the calibration monitoring, and radiative transfer model. Here, we briefly introduce the overall development strategy, flow chart for the intended baseline products, a few preliminary algorithm results and future plans.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.56-59
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• 2006

In this paper, Korea's first geostationary Communication, Ocean and Meteorological Satellte(COMS) program is introduced. COMS program is one of the Korea National Space Programs to develop and operate a pure civilian satellite of practical-use for the compound missions of meteorological observation and ocean monitoring, and space test of experimentally developed communication payload on the geostationary orbit. The target launch of COMS is scheduled at the end of 2008. COMS program is international cooperation program between KARI and ASTRIUM SAS and funded by Korean Government. COMS satellite is a hybrid satellite in the geostationary orbit, which accommodates multiple payloads of MI(Meteorological Imager), GOCI(Geostationary Ocean Color Imager), and the Ka band Satellite Communication Payload into a single spacecraft platform. The MI mission is to continuously extract meteorological products with high resolution and multi-spectral imager, to detect special weather such as storm, flood, yellow sand, and to extract data on long-term change of sea surface temperature and cloud. The GOCI mission aims at monitoring of marine environments around Korean peninsula, production of fishery information (Chlorophyll, etc.), and monitoring of long-term/short-term change of marine ecosystem. The goals of the Ka band satellite communication mission are to in-orbit verify the performances of advanced communication technologies and to experiment wide-band multi-media communication service mandatory.

• Korean Journal of Geomatics
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• 제1권1호
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• pp.27-33
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• 2001

There are invisible wars going on to preoccupy required satellite information for national defense, industry and living in the out space. Therefore, Korea has developed and successfully launched KOMPSAT (Korea Multi-Purpose SATellite), Korea's first multi-pur pose applications satellite, on December 21, 1999. In the course of geometric corrections with KOMPSAT-1 images, an accuracy of GCP collections is analyzed by the coordinated of digital map respective and an accuracy according to the GCP disposition was analyzed as well. For disposition of GCP, it turned out that even distribution on the whole screen contributes to promote accuracy. These are expected to used as basic data in putting the KOMPSAT-1 geometric correction into practical use.

• 대한원격탐사학회지
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• 제19권3호
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• pp.191-200
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• 2003

Remote sensing division of satellite technology research center (SaTReC) , Korea advanced institute of science and technology (KAIST) has developed a ground receiving and processing system for high resolution satellite images. The developed system will be adapted and operated to receive, process and distributes images acquired from of the second Korean Multi-purpose Satellite (KOMPSAT-2), which will be launched in 2004. This project had initiated to develop and Koreanize the state-of-the-art technologies for the ground receiving system for high resolution remote sensing images, which range from direct ingestion of image data to the distribution of products through precise image correction. During four years development from Dec. 1998 until Aug. 2002, the system had been verified in various ways including real operation of custom-made systems such as a prototype system for SPOT and a commercialized system for KOMPSAT-1. Currently the system is under customization for installation at KOMPSAT-2 ground station. In this paper, we present accomplished work and future work.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.262-265
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• 2007

Preliminary results are reported on ship detection using coherence images computed from cross-correlating images of multi-look-processed dual-polarization data (HH and HV) of ENVISAT ASAR. The traditional techniques of ship detection by radars such as CFAR (Constant False Alarm Rate) rely on the amplitude data, and therefore the detection tends to become difficult when the amplitudes of ships images are at similar level as the mean amplitude of surrounding sea clutter. The proposed method utilizes the property that the multi-look images of ships are correlated with each other. Because the inter-look images of sea surface are covered by uncorrelated speckle, cross-correlation of multi-look images yields the different degrees of coherence between the images and water. The polarimetric information of ships, land and intertidal zone are first compared based on the cross-correlation between HH and HV. In the next step, we examine the technique when the dual-polarization data are split into two multi-look Images.