• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.101-101
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• 2000

MSC(Multispectral Camera), which will be a unique payload on KOMPSAT-II, is designed to collect panchromatic and multi-spectral imagery with a ground sample distance of 1m and a swath width of 15km at 685km altitude in sun-synchronous orbit. The instrument is designed to have an orbit operation duty cycle of 20% over the mission life time of 3 years. MSC electronics consists of three main subsystems; PMU(Payload Management Unit), CEU(Camera Electronics Unit) and PDTS(Payload Data Transmission Subsystem). PMU performs all the interface between spacecraft and MSC, and manages all the other subsystems by sending commands to them and receiving telemetry from them with software protocol through RS-422 interface. CEU controls FPA(Focal Plane Assembly) which contains TDI(Timc Delay Integration) CCD(Charge Coupled Device) and its clock drivers. PMU provides a Master Clock to synchronize panchromatic and multispectral camera. PDTS performs compression, storage and encryption of image data and transmits them to the ground station through x-band.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 1995년도 한국우주과학회보 제4권2호
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• pp.36-36
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• 1995

No Abstract, See Full Text

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.493-495
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• 2007

Future sub-meter resolution LEO missions require simultaneous dual-polarization downlink and/or multiple channel downlinks in single polarization. Especially, dual-polarization is needed to cope with bandwidth limitation due to high speed data transmission. Current KARI 13m X-Band antenna system needs to be upgraded to cope with such downlink schemes. This paper describes brief discussions on engineering work regarding how to meet the new requirements with minimum impact on current system as well as C&M (Control and Monitoring) software.

• Advances in aircraft and spacecraft science
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• 제5권2호
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• pp.205-223
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• 2018

During launch a spacecraft is subjected to a variety of dynamical loads transmitted through the launcher to spacecraft interface or air-born transmission excitations in the acoustic pressure field inside the fairing. As a result, spacecraft are tested on ground to ensure and demonstrate the global integrity of the structure against these loads, to screen the flight hardware for quality of workmanship and to validate mathematical models. This paper addresses the numerical modelling and simulation of the low frequency sine and random vibration tests performed on electrodynamic shaker facilities to comprise the mechanical-borne transmission loads through the launcher to spacecraft interface. Consequently, the paper reviews techniques and methodologies to derive a reliable and representative coupled virtual vibration testing simulation environment based on experimental data. These technologies are explored with the main objectives to ensure a stable, reliable and accurate control while testing. As a result, the use of the derived simulation models in combination with the added value of improved control and signal processing algorithms can lead to a safer and smoother vibration test control of the entire environmental test campaign.

• 센서학회지
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• 제21권2호
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• pp.103-108
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• 2012

Radiofrequency(RF) signal is a key medium to the most of the present wireless communication devices including RF identification devices(RFID) and smart sensors. However, the most critical barrier to overcome in RFID application is in the failure rate in detection. The most notable improvement in the detection was from the introduction of EPC Class1 Gen2 protocol, but the fundamental problems in the physical properties of the RF signal drew less attention. In this work, we focused on the physical properties of the RF signal in order to understand the failure rate by noting the existence of the ground planes and noise sources in the real environment. By using the mathematical computation software, Maple, we simulated the distribution of the electromagnetic field from a dipole antenna when ground planes exist. Calculations showed that the dark area can be formed by interference. We also constructed a test system to measure the failure rate in the detection of a RFID transponder. The test system was composed of a fixed RFID reader and an EPC Class1 Gen2 transponder which was attached to a scanner to sweep in the x-y plane. Labview software was used to control the x-y scanner and to acquire data. Tests in the laboratory environment showed that the dark area can be as much as 43 %. One who wants to use RFID and smart sensors should carefully consider the extent of the dark area.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.130-133
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• 2007

In order to get high quality and high resolution image data from the space-borne camera system, the image chain from the sensor to the user in the ground-station need to be designed and controlled with extreme care. The behavior of the camera system needs to be controlled by ground commands to support on-orbit calibration and to adjust imaging parameters and to perform early stage on-orbit image correction, like gain and offset control, non-uniformity correction, etc. The operation status including the temperature of the sensor needs to be transferred to the ground-station. The preparation time of the camera system for imaging with specific parameters should be minimized. The camera controller needs to synchronize the operation of cameras for every channel and for every spectral band. Detail timing information of the image data needs to be provided for image data correction at ground-station. In this paper, the design of the camera controller for the AEISS on KOMPSAT-3 will be introduced. It will be described how the image chain is controlled and which imaging parameters are to be adjusted The camera controller will have software for the flexible operation of the camera by the ground-station operators and it can be reconfigured by ground commands. A simple concept of the camera operations and the design of the camera controller, not only with hardware but also with controller software are to be introduced in this paper.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.271-273
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• 2006

In this paper, we describe the MI2U ORB function which is a part of the flight software executed on SCU and controls MI2U/MI which is one of three payloads on COMS. The MI2U ORB function manages MI2U/MI redundancy and reconfiguration, monitors MI2U/MI equipment, performs FDIR, and provides the routing service of commands from Ground/IP (Interpreted Program) through the current used 1553 channel. The MI2U hardware achieves the interface between the SCU and the MI. The MI2U is connected to SCU through MIL-STD-1553B system bus. The MI2U has the internal redundancy but is used in cold redundancy. The MI2U ORB function considers that they are not expected to be simultaneously switched on. The connection combination between MI2U and MI is electrically cross-strapped. However the MI2U ORB function considers only two combinations (MI2U A + MI 1, MI2U B + MI 2). Other combinations can be manually achieved by ground in case of the emergency case.

• 한국항공우주학회지
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• 제49권6호
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• pp.481-488
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• 2021

인공위성의 원격명령 처리시스템은 상태감시, 제어 및 미션 실행을 위한 원격명령을 제공하는 유일한 통로이다. 국내의 인공위성은 과학 및 기술 위성, 다목적 위성 및 정지궤도 위성으로 나눌 수 있으며 CCSDS 표준 프로토콜을 사용하여 지상국과 통신을 수행한다. 그러나 기존의 국내개발 위성은 소프트웨어를 사용하여 원격명령어를 디코딩하여 소프트웨어 개발 및 검증 비용이 높고 하드웨어와 비교할 때 상대적으로 성능이 낮다. 본 연구에서는 원격명령 디코딩 ASIC을 이용한 원격 명령 처리시스템을 제시한다. 이 시스템의 하드웨어는 telecommand RAM, protocol RAM/ROM, telecommand ASIC, interface FPGA 및 relay block으로 구성되었다. 이 시스템은 인공위성이 사용하는 일반 명령 및 펄스 명령을 처리한다. 시스템을 시험 및 검증하기 위해 점검 장비 및 시험환경을 구축하였다. 제안한 ASIC 기반의 telecommand 처리시스템은 소프트웨어 기반 디코딩 시스템에 비해 개발 비용을 1/5로 줄였을 뿐만 아니라 성능은 10⁵배 향상되었다.

• 항공우주시스템공학회지
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• 제17권6호
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• pp.133-143
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• 2023

본 논문에서는 유무인 협업을 위한 유인회전익기에 의한 다수 무인기 운용통제기술의 요구도 검증을 위한 통합검증환경의 요구도 분석, 구현 및 검증에 대해 기술하였다. 통합검증환경은 유인회전익기 비행 모의, 무인항공기 비행 및 임무장비 모의, 무인항공기 제어 및 유인회전익기와의 통제권 변경을 위한 지상통제장비 모의, 유인회전익기 및 무인항공기 임무계획 작성 및 전송을 위한 운용통제장비 모의로 구성된다. 각각 구현된 구성품들은 소프트웨어/하드웨어 통합시험을 통해 요구도를 검증하였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.241-241
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• 2002

MSC(Multi-Spectral Camera) is a main payload of KOMPSAT(Korea Multi-Purpose Satellite)-II which will be launched in 2004. MSC will perform his mission with the GSD(Ground Sample Distance) of 1m, swath width of 15km and spectral range of 450nm~900nm at the altitude of 685km. MSC consists of three main subsystems. One is EOS(Electro-Optics Subsystem), another is PMU(Payload Management Unit) and the other is PDTS(Payload Data Transmission Subsystem). There is an SBC(Single Board Computer) in the PW to control all the other units and SBC software performs the interface with spacecraft and control all MSC sub-units. SBC software consists of a lot of tasks and manages them with the time criticalness. All tasks are designed to be scheduled and executed at the predetermined time in order to make sure that the mission of MSC system is achieved successfully. In this paper, the real-time task scheduling of the SBC software will be described and analyzed.