• 항공우주기술
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• 제6권1호
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• pp.209-212
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• 2007

복사 보정에 해당하는 NUC(Non-Uniformity Correction)은 MSC 각각의 픽셀들이 가지는 상이한 특성을 균일한 이미지를 얻기 위해 수행하는 작업이다. KOMPSAT-2의 MSC는 각 CCD pixel 별, 각 band 별 특성, 감도 및 시간에 따른 변화, CCD Geometry 등에 의해 왜곡 현상이 일어나게 된다. 검보정 과정에서는 위성 발사 전에 실험실에서의 충분한 실험과 Calibration 작업을 통해 얻어진 값들을 사용하여 Image Restoration, 상대 복사 보정, 절대 복사 보정 등의 작업들을 거쳐서 왜곡 현상을 보정하게 된다. 본 논문에서는 KOMPSAT-2의 NUC(HF NUC & LF NUC) 알고리즘을 이용하여 Panchromatic 밴드의 raw image의 NUC 보정작업 과정과 그 결과에 대해서 소개하고자 한다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.530-532
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• 2007

Multi-Spectral Camera(MSC) is a main payload on the KOMPSAT-2 satellite to perform the earth remote sensing. The MSC instrument has one(1) channel for panchromatic imaging and four(4) channel for multi-spectral imaging covering the spectral range from 450nm to 900nm using TDI CCD Focal Plane Array (FPA). The compression method on KOMPSAT-2 MSC was selected and used to match EOS input rate and PDTS output data rate on MSC image data chain. At once the MSC performance was carefully handled to minimize any degradation so that it was analyzed and restored in KGS(KOMPSAT Ground Station) during LEOP and Cal./Val.(Calibration and Validation) phase. In this paper, on-orbit image data chain in MSC and image data processing on KGS including general MSC description is briefly described. The influences on image performance between on-board compression algorithms and between performance restoration methods in ground station are analyzed and discussed.

• Journal of Astronomy and Space Sciences
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• 제17권2호
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• pp.309-316
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• 2000

KOMPSAT-2 will carry MSC(Multi-Spectral Camera) which provides 1m resolution panchromatic and 4m resolution multi-spectral images at the altitude of 685km sun-synchronous mission orbit. The mission operation of KOMSPAT-2 is to provide the earth observation using MSC with nadir pointing. KOMPSAT-2 will also have the capability of roll/pitch tilt maneuver using reaction wheel of satellite as required. In order to protect MSC from thermal distortion as well as direct sunlight, MSC shall be operated within the constraint of sun incidence angle. It is expected that the sunlight will not violate the constraint of sun incidence angle for normal mission operations without roll/pitch maneuver. However, during roll/pitch tilt operations, optical module of MSC may be damaged by the sunlight. This study analyzed sun incidence angle of payload using KOMPSAT-2 AOCS (Attitude and Orbit Control Subsystem) Design and Performance Analysis Soft ware for KOMPSAT-2 normal mission operations.

• 대한원격탐사학회지
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• 제17권3호
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• pp.211-218
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• 2001

대기복사모델인 MODTRAN을 이용해 다목적실용위성 2호 탑재체인 Multispectral Camera (MSC)의 총복사량에 대한 계산을 수행하고 그 결과를 분석해 보았다. 모델 계산에서 4계절 조건을 모의실험하기 위해 1월 15일, 7월 15일 계산에 대해 중위도 동절기 및 하절기 모델대기를, 4월 15일, 10월 15일에 대해 US 표준대기를 각각 사용했다. 다목적실용위성 2호 궤도 조건과 각 계절에 대한 대표적인 태양천정각 (solar zenith angle)이 고려되었다. 시정거리는 대류권 에어로솔 소광계수 (tropospheric aerosol extinction)에 해당하는 50km가, 지표의 알베도는 맑은 날 지구 연평균 값에 해당하는 0.135가 가정되었다. MSC 계약서 값은 위 일반적 조건을 가정하고 얻은 모델 계산 총복사량보다 MSC 관측 파장대역 대부분에서 상당히 크다는 것을 알게 되었다. 또한 균일한 지표 알베도를 가정하고 얻은 모델 결과의 분광파장 특징이 MSC 계약서 값의 경향과 다름을 보였다. 이들 결과로부터 향후 획득될 MSC영상은 비교적 어두운 영상이 될 것으로 추론된다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1102-1104
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• 2003

KOMPSAT-2 provides two different imaging methods, direct imaging and playback imaging. For playback imaging operation KOMPSAT-2 has a storage device called DCSU (Data Compression & Storage Unit) to hold images taken before. Compression function is necessary to save memory space and data transmission time to ground station. There are several parameters for compression like compression ratio. Due to DCSU architectural characteristics and KOMPSAT-2 operational limitations, there are some restrictions on selecting compression parameters. This paper will provide selecting guides on compression parameters.

• 대한공간정보학회지
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• 제17권2호
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• pp.55-60
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• 2009

본 연구에서는 경주시 내남면을 대상으로 KOMPSAT-2 MSC(Multi Spectral Camera) 영상(2007.06.12)을 기반으로 NDVI(Normalized Difference Vegetation Index)와 TCT(Tasseled-Cap Transformation) 영상 알고리즘을 적용하여 DN 분포도를 작성 하였다. NDVI 및 TCT DN 분포도와 산림 현장 조사 결과와의 비교 분석을 통하여 임상 분류 정확도 향상을 위한 영상 알고리즘 변별력 분석을 수행하고 마지막으로 현장조사 자료와의 중첩 분석을 통하여 임상분류 정확성을 검증 하였다. 본 연구를 통하여 KOMPSAT-2 MSC 영상을 이용하여 임상 분류 자동화 실용성에 대한 검토와 정밀 산림 임상도 제작과정에서 저비용 고효율성을 기대할 수 있으리라 사료된다.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2003년도 추계학술발표회 논문집
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• pp.417-422
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• 2003

The KOMPSAT-2 MSC(Multi-Spectral Camera), with high spatial resolution, is currently under development and will be launched in the end of 2004. A sensor model relates a 3-D ground position to the corresponding 2-D image position and describes the imaging geometry that is necessary to reconstruct the physical imaging process. The Rational Function Model (RFM) has been considered as a generic sensor model. form. The RFM is technically applicable to all types of sensors such as frame, pushbroom, whiskbroom and SAR etc. With the increasing availability of the new generation imaging sensors, accurate and fast rectification of digital imagery using a generic sensor model becomes of great interest to the user community. This paper describes the procedure to generation of the RPC (Rational Polynomial Coefficients) for KOMPSAT-2 MSC.

• 대한원격탐사학회지
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• 제23권5호
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• pp.431-437
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• 2007

Multi-Spectral Camera(MSC) on the KOMPSAT-2 satellite was developed and launched as a main payload to provide 1m of GSD(Ground Sampling Distance) for one(1) channel panchromatic imaging and 4m of GSD for four(4) channel multi-spectral imaging at 685km altitude covering l5km of swath width. Since the compression on MSC image chain was required to overcome the mismatch between input data rate and output date rate JPEG-like method was selected and analyzed to check the influence on the performance. In normal operation the MSC data is being acquired and transmitted with lossy compression ratio to cover whole image channel and full swath width in real-time. In the other hand the MSC performance have carefully been handled to avoid or minimize any degradation so that it was analyzed and restored in KGS(KOMPSAT Ground Station) during LEOP(Launch and Early Operation Phase). While KOMPSAT-2 had been developed, new compression method based upon wavelet for space application was introduced and available for next satellite. The study on improvement of image chain including new compression method is asked for next KOMPSAT which requires better GSD and larger swath width In this paper, satellite image chain which consists of on-board image chain and on-ground image chain including general MSC description is briefly described. The performance influences on the image chain between two on-board compression methods which are or will be used for KOMPSAT are analyzed. The differences on performance between two methods are compared and the better solution for the performance improvement of image chain on KOMPSAT is suggested.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.509-511
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• 2005

KOMPSAT -2 equipped with an optical telescope(MSC) will be launched in this year. It can take images of the earth with push-broom scanning at altitude 685Km. Its resolution is 1m in panchromatic channel with a swath width of 15 km After the MSC is tested and the performance is measured at instrument level, it is installed on satellite. The image passes through the electro-optical system, compression and storage unit and fmally downlink sub-systems. This integration procedure necessitates the functional test of all subsystems participating in the image chain. The objective of functional test at satellite level(Quick Look test) is to check the functionality of image chain by real target image. Collimated moving image is input to the EOS in order to simulate the operational environments as if KOMPSAT -2 is being operated in orbit. The image chain from EOS to data downlink subsystem will be verified through Quick Look test. This paper explains the Quick Look test of KOMPSAT -2 and compares the taken images with collimated input ones.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.620-623
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• 2005

KARI has prepared Calibration and Validation activities for the KOMPSAT-2 (KOrea Multi-Purpose SATellite-2) MSC data that will be launched at the end of this year. Firstly, we divided the Cal/Val activities of it to four parts, Spatial, Spectral, Radiometric and Geometric, and defmed the detailed Cal/Val items from them. Secondly, Cal/Val targets have been defined and manufactured for the role of them. Thirdly, we have made the plan and the procedure for the Cal/Val items, developed the codes for them, studied more detailed method to do them, and trained the Cal/Val activities using the foreign satellite image data by ourselves. KARI has been now setting up the KOMPSAT-2 LEOP plan with the Cal/Val activities, and probably will finish the EOP Cal/Val activities for the KOMPSAT-2 MSC data by the next April or May.