• Proceedings of the KSRS Conference
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• v.2
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• pp.776-779
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• 2006

KOMPSAT-5 that will be launched at the end of 2008 has a SAR (Synthetic Aperture Radar) payload. Since the Calibration and Validation of a satellite SAR is different from a passive optical camera as KOMPSAT-2 MSC and KOMPSAT-3 payload, we have started from the basis of SAR system. Firstly, the general SAR Cal/Val parameters have been gathered and defined. Secondly, we have been choosing the Cal/Val parameters suitable to KOMPSAT-5. Thirdly, the methods of SAR Cal/Val with the parameters have been studied. Fourthly, the requirement of Cal/Val devices and Cal/Val site has been studied.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.112-117
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• 1997

This paper presents a GA(Genetic Algorithms)-Optical control strategy for the control of the swing motion and the transverse position of the overhead crane. The overhead crane system is defined uncertain due to unknown system parameters such as payload and trolly mass. To control the overhead crane. the GA-Optimal control scheme is suggested. which transfers a trolly to a desired place as fast as possible and minimizes the swing of the payload during the transfer. The genetic algorithms are applied to fine digital optimal feedback gains. A computer simulation demonstrate the performance of the proposed the GA-digital optimal controller for the overhead crane.

• Journal of Astronomy and Space Sciences
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• v.17 no.2
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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.

• Journal of Astronomy and Space Sciences
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• v.19 no.3
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• pp.225-230
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• 2002

Synthetic Aperture Radar (SAR) has been used for mapping the surface geomorphology of cloudy planets like Venus as well as the Earth. The cloud-free Mars is also going to be scanned by SAR in order to detect buried water channels and other features under the very shallow subsurface af the ground. According to the 'Mid and Long-term National Space Development Plan' of Korea, SAR satellites, in addition to the EO (Electro-Optical) satellites, are supposed to be developed in the frame of the KOMPSAT (Korean Multi-Purpose Satellite) program. Feasibility of utilizing a SAR payload on KOMPSAT platform has been studied by KARI in collaboration with Astrium U.K. The purpose of the ShR program is Scientific and Civil applications on the Earth. The study showed that KOMPSAT-2 platform can accommodate a small SAR like Astrium’s MicroSAR. In this paper, system aspects of the satellite design are presented, such as mission scenario, operation concept, and capabilities. The spacecraft design is also discussed and conclusion is followed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.620-621
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• 2010

Thermal models are made to verify the process that operate in space orbit. In this study, thermal analysis model correlation was performed to satisfy the criteria of correlation. Ground thermal vacuum test results are used for the correlation thermal model in the process of thermal model verification.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1121-1123
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• 2003

The CCD (Charge coupled device) detector that is used to convert the light into electronic data is very important component in satellite camera. A Linear CCD Spectral detector shall be used in the MSC (Multi-Spectral Camera, to obtain data for high-resolution images) Payload. In this paper, the design concept of the CCD detector control module in the MSC CEU (Camera electronic unit) system which will be a payload on KOMPSAT is described in terms of H/W (clock speed and accuracy).

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.49.1-49.1
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• 2018

The MATS (Mesosphere Airglow/Aerosol Tomography Spectroscopy) satellite is the next Swedish science microsatellite. We report optical performance test results of the limb telescope, which is the major payload. This telescope is designed with "linear astigmatism-free" (LAF) off-axis optical system in order to have high optical performance across the wide field of view. We measured Modulation Transfer Function (MTF) and Encircled Energy Diameter (EED) of the limb telescope. Full field imaging tests show expected results without linear astigmatism across the full field of view ($5.67^{\circ}{\times}0.91^{\circ}$). Since the amount of stray light is from the earth and the sun, we also simulated and measured the stray light in the field image.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.12
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• pp.1232-1239
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• 2010

A high-resolution electro-optical camera (EOS-C Ver.3.0), the mission payload of an Earth observation satellite, is under development in Satrec Initiative. We designed this system to give improved thermal performance compared with the EOS-C Ver.2.0 which is the main payload of DubaiSat-1 by optimizing the active and passive thermal control design. We developed the Structural-Thermal Model (STM) and verified the design margin by performing the qualification level thermal vacuum test. We also conducted the verification of its Thermal Mathematical Model (TMM) through the thermal balance test. As a result, it was confirmed that TMM faithfully represents the thermal characteristics of the EOS-C Ver.3.0.

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.365-366
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• 2009

본 논문에서 개발된 시뮬레이터는 광학 탑재체의 성능예측에 있어 지배적인 영향을 미치는 MTF인자 및 PSF인자들을 수치해석프로그램인 MATLAB 상에서 계산하였다. 또한 광학해석 프로그램인 ZEMAX를 연동하여 광학계의 가공, 제조 그리고 정렬할 때 발생할 수 있는 오차들을 적용 수 있다. 이를 통하여 광학탑재체의 운용상 발생하는 Jitter, Smear, Detector sampling, Detector diffusion등의 MTF를 쉽게 구할 수 있으며 여기에 광학계 제조상의 문제를 직접 적용할 수 있다. 그 결과 이를 영상에 넣어 가상영상을 생성하여 광학 탑재체 성능 예측을 효율적으로 수행할 수 있게 되었다.

• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.69-70
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• 2008

본 논문은 광학 탑재체 성능의 MTF 예측에 있어, 광학 해석 프로그램인 ZEMAX와 MATLAB으로 구현된 기본 광학계 성능 해석 모델을 하나의 통합적인 툴 체계로 구현하였다. 그 결과 광학 탑재체 성능 해석에 광학계 설계, 제작/조립 및 궤도 상에서의 오차를 직접 반영할 수 있게 되었고 광학 탑재체의 초기 설계 단계에서 주요 설계인자를 도출하고, 지배적인 영향을 미치는 입력변수와 설계 요소들을 활용하여 광학 탑재체의 성능 예측을 수행할 수 있는 효율적이고 체계적인 틀을 개발하였다.