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Ma J.,Beijing Institute of Technology | Lin J.,Beijing Institute of Technology | Zhang W.,Luna Exploration and Space Engineer Center | Gao X.,Beijing Institute of Technology
Proceedings of the International Astronautical Congress, IAC | Year: 2012

Space Radiation Environment (SRE) often influences control system onboard during a flight process. It is becoming more important to research resist-radiation defending during deep space exploration and manned space flight. The research of SRE modeling and simulating orients to resist-radiation defending for control system. The main research work includes SRE conceptual model analyzing, SRE system modeling, designing and conclusion of SRE simulation system infrastructure. Building a whole SRE simulation system is a challenging work and the system scheme is helpful for related researchers to design a similar system. ©(2012) by the International Astronautieal Federation.

Wu W.,Luna Exploration and Space Engineer Center | Wang D.,Beijing Institute of Control Engineering | Hu H.,Beijing Institute of Control Engineering
Proceedings of the International Astronautical Congress, IAC | Year: 2012

The rendezvous and docking in lunar orbit is critical during sampling return mission. The paper proposes an autonomous determination approach for chaser spacecraft during rendezvous and docking process in lunar orbit. The approach estimates the absolute orbit parameters of chaser spacecraft during whole rendezvous and docking process by comprehensively utilizing the measurements of imaging sensor, rendevous radar and star sensor, as well as target spacecraft orbit extrapolation, integrating absolute orbit dynamics model, and designing a navigation filter by UKF algorithm. The approach provides the theoretical reference for rendezvous and docking project in lunar orbit. Copyright © (2012) by the International Astronautical Federation.

Wu W.-R.,Luna Exploration and Space Engineer Center | Lin Y.,Beijing Research Institute of Telemetry | Jie D.-G.,Luna Exploration and Space Engineer Center | Chen M.,Luna Exploration and Space Engineer Center
Yuhang Xuebao/Journal of Astronautics | Year: 2013

Fountain coding can resume the distributed data, and can improve the fluctuated signal reception accrued in Launcher and Missile telemetry system. A scheme of Concatenated Fountain Code and Turbo Product Code (TPC) is proposed, some key issues during Concatenation are emphasized, and performance of Bit Error Rate and Frame Lost Rate are discussed by using the baseband equipment test. As the test results indicated, the PCM-FM Telemetry System with LT+TPC Concatenated Code can improve the data reception up to 99.5% in the case of erase probability below 10%.

Wu W.-R.,Luna Exploration and Space Engineer Center | Wu W.-R.,Beihang University | Luo H.,Beijing Research Institute of Telemetry | Chen M.,Beijing Research Institute of Telemetry | And 2 more authors.
Xi Tong Gong Cheng Yu Dian Zi Ji Shu/Systems Engineering and Electronics | Year: 2012

In the first mission of satellite CE-2 travel from orbit of Luna to Libration points 2 in the Sun-Earth system, owing to ability of the ground equipment, the telemetry and data transmission system must conquer the technical difficulties, which are the problems of long distance and weak signal. Therefore some technical experiments are developed, which are study of weak signal capture and tracking, study of low loss demodulation, high performance of encode technology, design of tracking, telemetry and command (TT&C) and data transmission system and test experimentation. Experimental results indicate that telemetry and data transmission system has the ability of 1 500 000~1 700 000 km distance communication, it will be significantly useful for reference to the deep space exploration.

Wu W.-R.,Luna Exploration and Space Engineer Center | Jie D.-G.,Luna Exploration and Space Engineer Center | Ding X.-W.,Beijing Research Institute of Telemtry | Li H.-T.,Beijing Institute of Technology
Yuhang Xuebao/Journal of Astronautics | Year: 2014

The existing various noncoherent demodulation algorithms of GMSK cause biggish loss for deep-space missions. A modified preponderant noncoherent demodulation algorithm with Viterbi decoding for GMSK signals is proposed in this paper. The simulation model is built by analyzing the phase transfer law in the phase state grid map. The performance test of principium equipment demonstrates that the modified algorithm has low loss of demodulation performance and medium complexity. And compared with the best coherent demodulation algorithm, it only causes a loss about 0.6 dB actually in the bit error rate of 1e-4. It has been applied to the GMSK baseband equipment in a certain deep-space TT&C system and has demodulated data from ESA Herschel-Planck satellite successfully. ©, 2014, China Spaceflight Society. All right reserved.

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