“天问一号”火星探测器超高频(Ultra high frequency,UHF)频段中继通信系统作为中国首次火星探测任务实现的重要组成部分,负责为着陆巡视器与环绕器之间在火星进入、下降、着陆阶段(Entry,descent and landing,EDL)与火面巡视阶段提供...“天问一号”火星探测器超高频(Ultra high frequency,UHF)频段中继通信系统作为中国首次火星探测任务实现的重要组成部分,负责为着陆巡视器与环绕器之间在火星进入、下降、着陆阶段(Entry,descent and landing,EDL)与火面巡视阶段提供高效可靠的通信服务。本文对中国火星探测器UHF频段中继通信方案进行了介绍,给出中继通信系统的组成、技术指标及链路设计方法,并对在轨飞行试验数据进行了分析。结果表明,全新研制的“天问一号”探测器UHF频段中继通信系统圆满完成了任务目标,其设计、实现和应用为后续中国深空中继通信系统研制提供了技术参考。展开更多
“天问一号”火星探测任务是中国通过一次发射,实现对火星“绕、落、巡”的探测任务。火星探测任务的进入、下降及着陆段(Entry,Descent and Landing,EDL)是整个任务过程中最为重要的环节之一。基于该过程中继通信任务特点,介绍了“天...“天问一号”火星探测任务是中国通过一次发射,实现对火星“绕、落、巡”的探测任务。火星探测任务的进入、下降及着陆段(Entry,Descent and Landing,EDL)是整个任务过程中最为重要的环节之一。基于该过程中继通信任务特点,介绍了“天问一号”火星探测器为适应EDL段通信任务时序复杂、高自主性、黑障现象以及高动态性等特点的中继通信系统方案及关键技术。同时结合“天问一号”软着陆任务,对EDL段中继通信在轨验证情况进行了总结和分析。提出的中继通信系统方案圆满支持了“天问一号”火星探测EDL段中继通信任务。展开更多
Deep space communication is quite different from conventional ground communication due to its time-varying,complexity and large signal delay,which consequently affects communication quality and system efficiency.Adjus...Deep space communication is quite different from conventional ground communication due to its time-varying,complexity and large signal delay,which consequently affects communication quality and system efficiency.Adjusting the transmission parameters when the channel environment changes during the communication can guarantee the performance index of the system,and therefore improve communication efficiency. An adaptive transmission scheme of transceiver based on Consultative Committee for Space Data Systems(CCSDS)protocols is proposed in this paper. According to the variation of the deep space channel,the symbol rate of transmission data is adjusted dynamically by estimating the signal-to-noise ratio(SNR) of the receiver in real time and adjusting the channel environment. This scheme can improve the channel utilization and system throughput under the premise of limiting the system bit error rate. Furthermore,this scheme is successfully implemented in Xilinx Virtex-5 FPGA board.展开更多
The environmental conditions of Mars landing missions are much different from that of Earth reentry missions, including the distance between the spacecraft and the Earth, the atmosphere, landform, aerodynamic forces, ...The environmental conditions of Mars landing missions are much different from that of Earth reentry missions, including the distance between the spacecraft and the Earth, the atmosphere, landform, aerodynamic forces, thermal effects. Therefore there are more autonomy requirements, more flight phases, more uncertainties in modeling and analysis, and more difficulties in validation of the flight sequence. Firstly the challenges of Mars landing missions are summarized in this paper. Then the key issues for Mars landing missions are analyzed according to the phases of the landing process. Finally suggestions and proposals for further development for Mars landing technologies are given.展开更多
文摘“天问一号”火星探测器超高频(Ultra high frequency,UHF)频段中继通信系统作为中国首次火星探测任务实现的重要组成部分,负责为着陆巡视器与环绕器之间在火星进入、下降、着陆阶段(Entry,descent and landing,EDL)与火面巡视阶段提供高效可靠的通信服务。本文对中国火星探测器UHF频段中继通信方案进行了介绍,给出中继通信系统的组成、技术指标及链路设计方法,并对在轨飞行试验数据进行了分析。结果表明,全新研制的“天问一号”探测器UHF频段中继通信系统圆满完成了任务目标,其设计、实现和应用为后续中国深空中继通信系统研制提供了技术参考。
文摘“天问一号”火星探测任务是中国通过一次发射,实现对火星“绕、落、巡”的探测任务。火星探测任务的进入、下降及着陆段(Entry,Descent and Landing,EDL)是整个任务过程中最为重要的环节之一。基于该过程中继通信任务特点,介绍了“天问一号”火星探测器为适应EDL段通信任务时序复杂、高自主性、黑障现象以及高动态性等特点的中继通信系统方案及关键技术。同时结合“天问一号”软着陆任务,对EDL段中继通信在轨验证情况进行了总结和分析。提出的中继通信系统方案圆满支持了“天问一号”火星探测EDL段中继通信任务。
文摘Deep space communication is quite different from conventional ground communication due to its time-varying,complexity and large signal delay,which consequently affects communication quality and system efficiency.Adjusting the transmission parameters when the channel environment changes during the communication can guarantee the performance index of the system,and therefore improve communication efficiency. An adaptive transmission scheme of transceiver based on Consultative Committee for Space Data Systems(CCSDS)protocols is proposed in this paper. According to the variation of the deep space channel,the symbol rate of transmission data is adjusted dynamically by estimating the signal-to-noise ratio(SNR) of the receiver in real time and adjusting the channel environment. This scheme can improve the channel utilization and system throughput under the premise of limiting the system bit error rate. Furthermore,this scheme is successfully implemented in Xilinx Virtex-5 FPGA board.
文摘The environmental conditions of Mars landing missions are much different from that of Earth reentry missions, including the distance between the spacecraft and the Earth, the atmosphere, landform, aerodynamic forces, thermal effects. Therefore there are more autonomy requirements, more flight phases, more uncertainties in modeling and analysis, and more difficulties in validation of the flight sequence. Firstly the challenges of Mars landing missions are summarized in this paper. Then the key issues for Mars landing missions are analyzed according to the phases of the landing process. Finally suggestions and proposals for further development for Mars landing technologies are given.
