• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.508-510
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• 2001

최근 우주산업의 급속한 발달로 다양한 목적의 인공위성들이 개발되고 있다. 이러한 인공위성들은 그 사용 목적에 따라 다르지만 매우 많은 양의 데이터들을 다루게 된다. 이러한 데이터에는 각각의 주어진 임무에 사용되는 정보들이 대부분을 차지하지만 위성자체의 상태 데이터도 릴 정시간마다 화인을 해주어야 한다. 위성의 상태 데이터는 위성 각 부분의 이상유무나 위치, 시간 등 위성이 정상적으로 그 역할을 수행하고 올바른 궤도를 유지하는데 필요한 정보들이다 위성탑재 소프트웨어는 하드웨어 데이터나 위성의 상태 데이터를 심해진 시간간격마다 일어 메모리에 저장해 두는 일을 한다. 다목적실용위성 2호에서 이러한 데이터 획득을 자동적으로 수행하기 위해 매 시간간격마다 요구되는 데이터를 테이블 형식으로 헤더파일에 생성하는 프로그램을 구현하였다. 이 구현된 프로그램을 이용하여 다목적실용위성 2호의 탑재소프트웨어가 개발되고 있다.

• Aerospace Engineering and Technology
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• v.13 no.2
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• pp.108-114
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• 2014

This paper describes the orbit accuracy of KOMPSAT-5, which has been in normal operations since the launch on Aug. 22, 2013. The analysis on the various GPS related data and the different methodologies for orbit estimation are carried out and compared with each other. The accuracy of precise orbit is confirmed to be 12.8cm($1{\sigma}$) on average using data from the in-flight dual frequency GPS receiver, GPS precise ephemeris, and IGS stations. In addition, the orbit estimation using single frequency GPS receiver provides the orbit solution around 2m level. And, the accuracy of orbit processing is 5m using on-board navigation solution, which has about 10m accuracy.

• Aerospace Engineering and Technology
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• v.1 no.1
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• pp.65-71
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• 2002

KOMPSAT-1 AOCS mode divided into three major mode like Sun, Maneuver, Science Mode. The Maneuver mode consist of attitude hold and Δ-V Burn submode. This paper focus on the analysis of AOCS Maneuver Mode characteristics based on on-orbit playback data. The nadir pointing performance of attitude hold submode and the process for Δ-V Burn firing with plus/ minus 90 degree pitch/ roll maneuvering was verified. And also verified that the on-orbit performance meets the AOCS subsystem specification as designed.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2003.04a
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• pp.22-25
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• 2003

EOC(Electro Optical Camera)는 한반도 및 전 세계 육지 영역 관측용으로 설계되었다. EOC는 1999년 12월 21일 발사된 다목적 실용위성 1호에 탑재되어 가시광 대역(510 ～730nm)으로 입사하는 복사 정보를 수집해 왔다. 획득된 EOC 영상 자료는 다목적 실용위성 1호의 탑재체 자료전송 시스템(Payload Data Transmission System, PDTS)을 통해 지상으로 전송되며, 수신된 자료에 대한 방사 보정 및 기하 보정 등의 일련의 전처리(Pre-processing) 과정을 거쳐 EOC 표준 영상이 생성된다. EOC 영상에 대한 MTF 보상은 방사 보정 후 수행될 수 있으며, 다목적 실용위성 지상국에서는 사용자의 요구에 따라 EOC 영상에 대한 MTF 보상을 수행하고 그 결과를 제공한다. MTF 보상은 EOC의 점 확산 함수(Point Spread Function)를 이용하여 수행되며, 현재 Wiener 필터를 이용하여 수행되고 있다. 본문에서는 현재 다목적 실용위성 1호 영상처리시스템의 EOC 영상에 대한 MTF 보상을 소개하고, EOC의 점 확산 함수에 기초하여 역 필터(Inverse Filter) 및 의사 역 필터(Pseudo Inverse Filter)를 제작, EOC 영상에 대한 MTF 보상 수행 후 그 결과를 Wiener 필터를 이용한 결과와 비교, 분석한다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.3
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• pp.45-50
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• 2004

The design of reaction wheel control logic is critical to achieve the spacecraft attitude stabilization and performance requirements for the successful mission. Due to various uncertainties on orbit there exist limitation to obtain the model parameters through the ground tests and to design the associated control logic. Thus, the model parameter correction using on-orbit data is essential to the control performance on orbit. This paper performs the system identification using KOMPSAT-1 telemetry data and extracts the model parameters of the reaction wheel. Moreover, the reaction wheel is remodeled and compared with the ground test results.

• Korean Journal of Remote Sensing
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• v.17 no.3
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• pp.211-218
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• 2001

We have performed the calculation of total radiances for the KOMPSAT-2 Multispectral Camera (MSC) using a radiative transfer model of MODTRAN and examined its results. To simulate four seasonal conditions in the model calculation, we used model atmospheres of mid-latitude winter and summer for calculations of January 15 and July 15, and US standard for April 15 and October 15, respectively. Orbital parameters of KOMPSAT-2 and the seasonal solar zenith angles were taken into account. We assumed that the meteorological range is the tropospheric aerosol extinction of 50 km and surface albedo is the global average of clear-sky albedo of 0.135. MSC contract values are found to be considerably greater in the MSC spectral range than the total radiances calculated with the above general conditions. It is also shown that the spectral behavior of model results with the constant surface albedo differs from the pattern of MSC contract values. From these results, it can be inferred that the forthcoming MSC images would be somewhat dark.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.8
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• pp.138-144
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• 2004

Satellite generates a complex electromagnetic noise by conducted and radiated coupling effect of the various electrical instruments. This noise may cause serious problems on the satellite system. To minimize the electromagnetic coupling effects and maintain the system safety margin, system noise reduction technique should be applied from the beginning of the system design. The KOMPSAT-2 system is evaluated by measuring the conducted noise on system electrical power leads and verifying a 6dB system safety margin under the complex noise environment with current injection. This paper describes the KOMPSAT-2 system evaluation result performed on ETB(Electrical Test Bed) and the analysed noise element, the analysed result will be reflected on FM(Flight Model) EMC test.

• Journal of Satellite, Information and Communications
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• v.10 no.3
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• pp.102-108
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• 2015

With the constantly increasing demand of domestic and oversea satellite images, there is also a growing demand to rapidly acquire images after the satellite image collection planning of KOMPSAT-2/3/5. Therefore, it has been increasing to use the korea ground station and oversea ground station to keep pace with increased demand. The KARI is operating Data Ingestion System of the KOMPSAT-2/3 in Svalbard, where the satellite images have been received at least four or six times a day. The KARI is planning to operate oversea receiving system for KOMPSAT-5/3A. This paper introduces the polar data ingestion system operating in Norway, and presents the process of design and development for Polar Integration receiving system in preparation of multiple satellite operation.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.17-22
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• 2006

Anhydrous hydrazine and its methyl derivatives MMH and UDMH have been safety used as monopropellant and bipropellant fuels in thousands of satellites and expendable launch vehicles. Since KOMPSAT program, We have been developing skills on the hydrazine propulsion system for several years. This paper presents an overview of the hydrazine for the space application - propellant overview, material compatibility, handling cautions and the future of hydrazine systems.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.04a
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• pp.179-182
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• 2007

The new KOMPSAT in preliminary design phase will utilize 4.45 N monopropellant thrusters for attitude and orbit control. In this paper, a numerical plume analysis is performed to verify the effects of thruster plume on the satellite with a 3-D satellite base region model by DSMC. As a result, plume behaviors such as overall plume temperature, total density and thermal radiation to solar array are estimated.