• Journal of Satellite, Information and Communications
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• v.5 no.1
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• pp.63-68
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• 2010

Satellite structure should be designed to support safely the payload and several actuators under launch and on-orbit environments. After the configuration design of satellite, the structural analysis is performed using quasi-static load provided by launch vehicle manufacturer for detail design of satellite. In order to verify the safety of satellite structure designed using quasi-static loads, launch vehicle manufacturer performs coupled load analysis with satellite and launch vehicle models. For developing satellite, satellite model was reduced into the Craig-Bampton model for coupled load analysis, and delivered to the launch vehicle manufacturer. Launch vehicle manufacturer have done the coupled load analysis, and offered the acceleration and displacement results to the satellite manufacturer. From the analysis results, we have confirmed that satellite is designed safely and there is no possibility of interference and conflict in the inner/outer side of satellite.

• Journal of Satellite, Information and Communications
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• v.5 no.1
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• pp.80-84
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• 2010

Satellite structure should be designed to accommodate and support safely the payload and equipments necessary for its own missions and to secure satellite and payloads from severe laucnch enviroments. The lauch environments imposed on satellites are quasi-static accelerations, aerodynamic loads, acoustic loads and shock loads. To qualify the structure design against low-frequency dyanmic enviromnent, sine vibration test should be performed. During sine vibration test, the notchings are implemented in order to keep the payloads and equipments from excessive loading at their own main modes. This paper deals with sine test prediction, sine vibration test results, comparison of predicted values and tested values, and verification of Finite Element Model.

• Electronics and Telecommunications Trends
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• v.21 no.4 s.100
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• pp.107-117
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• 2006

위성 탑재체 제조 산업은 기초 과학이 뒷받침된 초정밀 기계 공학, 첨단 전자 기술, 극한 환경 기술 및 신소재 공학 등과 같은 첨단 산업의 집합체라 할 수 있다. 현재 미국을 비롯한 서구 선진국에서 진행중인 탑재체 기술동향을 보면, 폭발적으로 증가하는 위성수에 따라 위성 궤도가 부족하고 주파수 자원이 고갈되고 있는 상황에서 통신 위성의 효율성과 성능을 향상시킬 수 있는 신호처리 탑재(OBP) 위성과 통신기능을 포함한 다양한 기능을 가진 복합위성 개발이 진행되고 있으며 주파수 대역의 포화와 광대역 멀티미디어 서비스 제공 등을 위해 보다 높은 주파수의 준 밀리미터파 대역(Ka 대역) 위성 개발이 활발히 이루어지고 있다. 국내에서는 현재, 2008년 발사를 목표로 마이크로스위치 매트릭스(MSM)가 탑재되어 빔간 스위칭이 가능하도록 설계된 통신해양기상위성(COMS)용 통신 탑재체(SACOM) 개발이 진행중이다. 국내의 위성탑재용 RF 부품분야는 1990년부터 위성 중계기 시스템의 기본적인 설계, 조립, 종합화, 시험기술을 바탕으로 통신위성 탑재체용 초고주파 부품을 개발하여 왔으며, 2000년대에는 Ku 대역(12/14GHz) 및 Ka 대역(20/30GHz) 기술인증모델(EQM) RF 부품을 성공적으로 개발하였다. 이를 바탕으로 통신해양기상위성 통신탑재체용 Ka 대역 RF 부품이 현재 우주인증 모델(QM)의 개발이 완료되었으며 비행 모델(FM) 개발이 진행중이다.

• Journal of Space Technology and Applications
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• v.2 no.2
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• pp.121-136
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• 2022

Automatic Identification System used in ship communication is required for marine control way, including monitoring of vessel operation in coastal and exchanging of information for safety navigation between them. But, it uses a very high frequency band of approximately 160 MHz, and at the same time, due to the curvature of Earth, there is a limit to the communication distance. Several demonstrations were made successfully over satellite, but not much work has been done yet through cube-satellite which has low-orbit at 500 km altitude. Here, we demonstrate a reception test of AIS (automatic identification system) receiver for a cube-satellites using software-defined radio (SDR). We collected AIS data from ship at port of Busan, Korea, using R8202T2 SDR and established to transmit them using Adam-Pluto and Matlab Simulink. The process of weakening the signal strength to a satellite was constructed using attenuator. Through above process, we demonstrated whether AIS data was successfully received from the AIS payload.

• Journal of Aerospace System Engineering
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• v.18 no.2
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• pp.104-116
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• 2024

A satellite is ultimately verified by performing a coupled load analysis with the launch vehicle. To increase the accuracy of the coupled load analysis results, it is important to have good accuracy of the finite element model. Therefore, finite element model correlation is essential. In general, model correlation is performed by changing the material properties and thickness one by one, but this process takes a lot of time and cost. The current paper proposes an efficient model correlation method using optimization. Significant variables were selected through analysis of variance, and the time and cost required for analysis and optimization were reduced by using the Kriging surrogate model. The method proposed in this paper can be applied only with the vibration test results, and it has a great advantage in terms of efficiency in that it can significantly reduce the numerical calculation cost and time required.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.4
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• pp.318-327
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• 2017

Synthetic Aperture Radars (SARs) that can be performed regardless of weather and day-and-night conditions have been developed for Earth remote sensing in recent decades. Korea Aerospace Research Institute (KARI) has developed and launched successfully the KOrea Multi-Purpose SATellit-5 (KOMPSAT-5) which is the first Korean SAR satellite in 2013, and is currently developing the KOMPSAT-6 which is the next generation series of the SAR satellite. This paper describes the development of the system performance analysis simulator which is necessary for spaceborne SAR payload design and analysis. The system performance analysis simulator consists of the antenna pattern generation simulator, the SAR performance analysis simulator, and the image quality analysis simulator. The simulation results of this research show that this simulator can be applicable as the design and analysis tool for the spaceborne SAR payload system during the design phase.

• Aerospace Engineering and Technology
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• v.6 no.2
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• pp.52-59
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• 2007

Telecommunication satellite consists of a bus system and an RF payload system with high efficiency and high gain reflector antennas. Antenna measurement and also RF system performance (antenna under test, payload and satellite level) have to be evaluated enough before launching in the far-field range or equivalent test range. Basically far-field range is required in a range from two hundred meters to several kilo meters, and it is highly constrained to the externa1 environment, like the RF and the whether environment So the compact antenna test range is developed and used efficiently without external environments as in-door facility. This paper describes the configuration of the compact antenna test range, the range error, and the physical concept of the plane wave illumination Also, it provides a overall design of the anechoic chamber and range parameter values to accommodate the precision measurements in antenna test range.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.641-642
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• 2011

저궤도 위성은 지상과의 접축시간이 극히 제한되어 있어 위성에서 생성된 원격측정 데이터들을 위성의 대용량 메모리에 저장하였다가 지상과의 접촉시간에 저장된 데이터를 지상으로 전송하는 방식으로 운영된다. 위성에 저장할 수 있는 전체 데이터 크기는 대용량 메모리의 크기와 지상과의 통신 가용시간에 따라 제한을 받게 된다. 대용량 메모리 저장용량과 다운링크 버짓을 만족해야 하므로 일반적으로 각 탑재체로부터 수신하여 위성에 저장되는 원격측정 데이터들은 종류별로 일정한 주기를 가지게 되고 그 크기도 고정되어 있다. 그리고 각 데이터 종류별로 저장여부를 지상명령으로 조절할 수 있도록 되어 있다. 그러나 생성되는 데이터가 일정하지 않고 비주기성을 갖는 경우 데이터량을 예측할 수 없으므로 지상명령으로 데이터 저장여부를 제어하는 것은 거의 불가능하다. 이러한 경우에 생성되는 데이터량을 모니터링하면서 데이터를 전송할 수 있는 자동화된 데이터 통신 방식이 요구된다. 본 논문은 저궤도 위성 탑재체에서 비주기적으로 생성되는 데이터를 자동으로 전송받기 위한 데이터 자동 전송기능과 시험 결과에 대해서 기술하였다.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.258-261
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• 2003

한반도와 그 주변 지역에 멀티미디어 서비스를 제공하기 위해 통신방송위성(CBS: Communications and Broadcastings Satellite) 탑재체의 Ku 대역 안테나가 개발되었다. Ku 대역 안테나는 성능 요구 조건을 만족하도록 설계 되었으며 일련의 시험을 통해 성능 검증이 이루어졌다. 일련의 시험은 초기 성능 시험(IFPT: Initial Functional Performance Test), 환경 시험, 최종 성능 시험(FFPT: Final Functional Performance Test)으로 구성되며 이를 통해 반사 손실, EOC(Edge Of Coverage) 이득, 사이드로브 레벨, 교차 편파 분리도등의 전기적 성능과 발사 및 우주 환경에서 강건함이 확인되었다.

• Current Industrial and Technological Trends in Aerospace
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• v.9 no.1
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• pp.90-101
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• 2011

In this article, we introduce the technologies and trend of technical evolution of Payload Data Handling Unit (PDHU) for Earth Observation Satellites. As well, we review the efforts for the Koreanization of PDHU so far, and conclude with some suggestions for future work.