http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
신용설,박찬국 한국항공우주학회 2021 International Journal of Aeronautical and Space Sc Vol.22 No.2
In this paper, environmental tests were conducted with a MEMS (micro-electro mechanical system) oscillator, which is known to be robust under harsh environmental conditions, and comparisons with the existing TCXO (temperature-controlled crystal oscillator) were conducted. And the results of the environmental tests of a GNSS receiver equipped with the MEMS oscillator were compared with the test results of the existing GNSS receiver. The oscillator undergoes considerable performance variation due to the surrounding environments, and in particular, a TCXO, which improves the frequency stability during temperature changes, is widely used in most GNSS receivers. The GNSS receiver for KSLV-II also uses the TCXO type, with its performance evaluated through environmental tests in which physical loads are applied, such as high and low temperatures, vibration, and pyrotechnic shocks. The TCXO in use met the specification in most environmental tests, but the frequency output from the TCXO changed abruptly at the instant of a pyrotechnic shock impact causing loss of signal tracking. But the GNSS receiver with the MEMS oscillator is not affected under the pyrotechnic shock test and the performance does not degrade under the temperature test and vibration test showing the feasibility of the MEMS oscillator for use in the GNSS receiver.
Design of a GNSS Antenna to Prevent LNA Saturation and Intermodulation Caused by S-Band Signals
신용설,박찬국 한국항공우주학회 2020 International Journal of Aeronautical and Space Sc Vol.21 No.3
In this paper, a Global Navigation Satellite System (GNSS) antenna design which prevents low-noise amplifier (LNA) saturation (compression) and intermodulation caused by S-band signals is proposed to improve the reception of GNSS signals. A simulation was conducted to determine which method can more efficiently decrease the S-band signal while maintaining the noise figure and the antenna gain concurrently. Considering the simulation results, an LNA is manufactured and an LNA performance test is conducted. System-level tests are performed to verify the new GNSS antenna function and to assess the performance improvement. The test results showed that the proposed antenna with the new LNA operates robustly without being affected by signals radiated from nearby S-band antennas while also meeting the required specifications.
한국형발사체용 위성항법수신기의 시각동기신호 Holdover 성능분석
신용설,권병문,문지현,마근수 한국항공우주학회 2015 한국항공우주학회 학술발표회 논문집 Vol.2015 No.11
한국형발사체용 위성항법수신기는 지구를 공전하는 항법위성의 신호를 수신하여 발사체의 실시간 항법정보와 시각동기신호를 생성한다. 일반적인 위성항법수신기는 실시간 항법정보만을 제공하나, 한국형발사체용 위성항법수신기는 발사체의 각 서브시스템의 시각동기를 위한 시각정보를 1PPS(1 Pulse Per Second)와 IRIG-B(Inter-Range Instrumentation Group Time Codes B)형태로 제공한다. 항법신호가 불가능한 지역에 있거나 안테나와의 연결이 일시적으로 끊어지는 경우에도 시각동기신호는 유지될 수 있으나 그 정확도는 크게 감소한다. 본 논문에서는 한국형발사체용 위성항법수신기 개발모델에 대해 항법신호가 일시적으로 단절되는 Holdover 구간의 시각동기신호 성능을 분석하고 이를 상용 시각수신기와 비교해본다. The GNSS receiver for KSLV(Korea Space Launch Vehicle)-II can calculate the real-time navigation solution and timing information by receiving Earth-orbiting navigation satellites signals. A GNSS receiver generally provides real-time navigation information only, the KSLV-II GNSS receiver provides the timing information in a form of 1PPS(1 Pulse Per Second) and IRIG-B(Inter-Range Instrumentation Group Time Codes B). In case of signal blockage or temporal loss of connection with antenna, which is called holdover period, the timing information can be maintained but its accuracy might be highly degraded. The comparative holdover performance tests for KSLV-II GNSS receiver and commercial timing receiver are described and the results are investigated quantitatively in this paper.
시계 바이어스 변화율을 이용한 반송파 DGPS의 성능 향상
신용설(Yong Sul Shin),박찬국(Chan Gook Park) 한국항공우주학회 2005 韓國航空宇宙學會誌 Vol.33 No.12
본 논문에서는 GPS 신호가 자주 단절되는 환경하에서도 안정한 위치 해를 제공하는 반송파 DGPS 방법을 제안한다. 시계 바이어스 변화율을 이용하여 큰 오차가 포함된 측정치 채널을 제거함으로써 더욱 정확한 위치 해를 제공하는 알고리듬을 구현하였다. 가시 위성의 앙각과 시계 바이어스 변화율의 관계를 살펴보고, 적절한 임계치를 제안하였으며, 구현된 알고리듬이 실데이터에서도 성능이 우수함을 상용프로그램과 비교하여 보였다. This paper presents the carrier phase DGPS method providing a stable navigation solution under the condition of frequent blockage of the GPS signals. The proposed algorithm reject the channels having large errors using a clock bias drift and then calculated the more accurate solution. By investigating the relation between visible satellites' elevation and their clock bias drift, a proper threshold is set. Simulation shows that the presented result is as good as that of commercial system with real data.