高轨飞行器GNSS定位技术研究

发布时间：2018-06-30 06:11

本文选题：全球卫星导航系统 + 高轨飞行器　；参考：《国防科学技术大学》2016年博士论文

【摘要】：随着人类太空探索任务数量的逐年递增,自主定位与导航将逐渐取代地面测控,成为航天飞行器在轨自主运行必不可少的功能。包括中国探月工程在内的高轨与深空探测任务对全球导航卫星系统(GNSS)在高轨的应用提出迫切需求。相比日渐成熟的低轨飞行器GNSS定位技术,高轨飞行器GNSS定位还存在着可见卫星数少、几何精度因子差、信号接收的载噪比低等不利因素。本文针对高轨飞行器GNSS定位中的技术问题,分析了高轨飞行器利用GNSS下行导航信号和星间链路信号定位的性能并对其进行了优化设计,研究了北斗卫星利用其它GNSS系统完成应急定位的可行性并对星载接收天线进行优化设计,探索了GNSS下行导航信号与星间链路信号的联合接收算法并分析了信道非理想特性的影响。(1)论文针对探月飞行器所在的高轨弱信号环境,评估了GNSS多星座组合时,环月飞行器接收GNSS主瓣、旁瓣信号的可用性。通过可见卫星数、接收信号载噪比、几何精度因子等参数,评估了环月飞行器使用“美国全球定位系统(GPS)”、“中国北斗卫星导航系统(北斗)”、“俄罗斯格洛纳斯全球导航卫星系统(格洛纳斯)”和“欧盟伽利略卫星导航系统(伽利略)”以及它们的各种组合实现定位的可行性。证明了使用全向天线接收四大GNSS系统下行导航信号的主瓣、旁瓣信号时均无法完成定位;使用定向天线提高接收增益使得旁瓣信号可用后,至少需要三个GNSS系统联合,才能实现飞行器全程定位。三系统组合中,GPS、北斗和伽利略系统组合的几何精度因子最优,四系统组合的几何精度因子可改善16.93%。研究成果为高轨飞行器多系统联合的接收机设计提供理论参考。(2)为解决GNSS的下行导航信号为探月飞行器定位时载噪比过低的问题,提出利用GNSS的星间链路信号为高轨飞行器定位的方法。以加权距离均方误差最小为优化目标,对探月飞行器和导航卫星接收星间链路信号的性能进行联合优化。提出一种兼顾探月飞行器定位与卫星星间通信测距的导航卫星宽波束星间链路模式,并设计了与之相匹配的星间链路环波束发射天线。对比分析结果表明:所设计的星间链路实现了支持探月飞行器从GNSS卫星轨道高度到月球轨道高度的定位与卫星星间测距通信的功能。仿真计算与实测数据的对比证明探月飞行器利用该模式星间信号定位的性能优于接收GNSS下行导航信号定位的性能。(3)为实现北斗系中、高轨卫星在星地通讯中断情况下的自主定位,提出北斗卫星利用GPS和格洛纳斯系统的下行导航信号进行定位的方法。分析了接收信号的多普勒频移、多普勒频移变化率、通道隔离与带外抑制、可见卫星数、载噪比、几何精度因子。同时以几何距离均方误差最小为优化目标,分析了中地球轨道、地球静止轨道、倾斜地球同步轨道上的北斗卫星利用星载GNSS接收机接收其民用信号的能力;获得三种轨道上接收性能最优的天线参数,并设计了相应的接收天线方向图,为北斗卫星应急定位的星载接收机设计提供参考。(4)论文利用高轨飞行器同时接收GNSS下行导航信号和星间链路信号的有利条件,分别提出了“GNSS的星间强信号辅助下行弱信号的矢量环联合跟踪算法及改进的无偏跟踪算法”、“GNSS的下行导航信号与星间链路信号联合的快速定位算法”。前者通过强信号辅助解决了高轨GNSS弱信号接收时矢量延迟锁定环路时跟踪抖动大的问题,通过GNSS下行导航信号和星间链路信号的系数加权消除了传统矢量延迟锁定环的跟踪偏差;后者解决了高轨GNSS信号条件下首次定位时间过长的问题,将定位时间缩短为正常情况的1/6。另外,针对北斗卫星利用GNSS信号定位的高精度应用,分析了幂方型和余弦型信道非理想特性导致BOC和BPSK调制的估计精度损耗,提出了高精度信号接收背景下的通道优化建议。最后总结本文研究成果,展望下一步将要开展的工作。本课题为将来高轨飞行器摆脱地面测控网的局限,实现高轨飞行器在轨自主定位与导航提供了理论支撑。
[Abstract]:As the number of human space exploration tasks increases year by year, autonomous positioning and navigation will gradually replace ground measurement and control and become an indispensable function of the autonomous operation of the spacecraft. The high rail and deep space exploration tasks, including the Chinese lunar exploration project, need an urgent need for the application of the global navigation satellite system (GNSS) on the high track. The increasingly mature GNSS positioning technology for low rail vehicles, the GNSS positioning of the high rail aircraft still exists the disadvantages of less visible satellite, poor geometric precision factor and low signal reception ratio. This paper analyzes the technical problems in the GNSS positioning of the high rail aircraft, and analyzes the use of the GNSS downlink navigation signal and the intersatellite link signal. The performance of the positioning and optimization design is carried out. The feasibility of using other GNSS systems to complete the emergency positioning of the Beidou satellite is studied and the satellite borne receiving antenna is optimized. The joint reception algorithm of the GNSS downlink navigation signal and the inter satellite link signal is explored and the influence of the non ideal characteristics of the channel is analyzed. (1) the thesis is aimed at the exploration of the moon. In the high rail weak signal environment where the aircraft is located, the availability of the GNSS main lobe and sidelobe signal for the GNSS multi constellation combination is evaluated. Through the parameters such as the number of visible satellites, the signal to noise ratio and the geometric precision factor, the use of the United States full ball positioning system (GPS), "China Beidou satellite navigation system", is evaluated. It is proved that the use of the omnidirectional antenna to receive the main lobe of the downlink signal of the four GNSS systems and the sidelobe signal can not be completed. Using a directional antenna to increase the receiving gain so that the sidelobe signal is available, at least three GNSS systems are needed to achieve full positioning of the aircraft. In the three system combination, the geometric precision factor of the combination of the GPS, the Beidou and Galileo system is optimal, and the geometric precision factor of the four system combination can improve the 16.93%. research results for the high rail aircraft. The joint receiver design of the system provides a theoretical reference. (2) in order to solve the problem of the low carrier noise ratio of GNSS's downlink navigation signal to the lunar exploration vehicle, the method of using the intersatellite link signal of GNSS to locate the high rail vehicle is proposed. The performance of inter satellite link signal is optimized jointly. A wide beam inter satellite link model of navigation satellite is proposed, which takes both the location of the lunar spacecraft and satellite communication between satellites. The matching of the inter satellite link beam transmitting antenna is designed. The result of comparison and analysis shows that the established inter satellite link is able to support the lunar exploration aircraft. From the altitude of the GNSS satellite orbit to the orbit height of the moon and the function of satellite satellite distance communication. The comparison between the simulation calculation and the measured data shows that the performance of the lunar probe using this mode is better than the performance of receiving the GNSS downlink navigation signal. (3) in the real Beidou system, the high orbit satellite is interrupted by the satellite communication. In the case of autonomous positioning, the method of positioning the Beidou satellite using the downlink navigation signal of GPS and the GNS system is proposed. The Doppler shift of the received signal, the change rate of Doppler frequency shift, the channel isolation and out of band suppression, the number of visible satellites, the carrier noise ratio and the geometric precision factor are analyzed, and the minimum mean square error of geometric distance is optimized. The aim is to analyze the ability of the Beidou satellite in the geostationary orbit of the earth orbit, the geostationary orbit and the geosynchronous orbit of the earth to receive its civil signal by the satellite borne GNSS receiver, and obtain the antenna parameters with the best receiving performance on the three tracks, and design the corresponding antenna square graph for the satellite borne receiver of the Beidou satellite emergency positioning. (4) (4) using the favorable conditions for the simultaneous reception of the downlink navigation signal and the intersatellite link signal of the high rail vehicle, the paper proposes the "GNSS's joint tracking algorithm for the vector ring of weak signal and the improved unbiased tracking algorithm", "the combination of the downlink navigation signal of GNSS and the intersatellite link signal." The former solves the problem of large tracking jitter when the vector delayed lock loop of the high rail GNSS weak signal is received by the strong signal auxiliary, and eliminates the tracking deviation of the traditional vector delayed lock loop through the coefficient weighting of the GNSS downlink navigation signal and the inter satellite link signal; the latter solves the high track GNSS signal condition under the condition of the high rail signal. For the first time, the location time is too long, and the positioning time is shortened to the normal 1/6.. In view of the high precision application of the Beidou satellite using GNSS signal positioning, the estimation precision loss of the power square and the cosine channel non ideal characteristics leading to the estimation of the BOC and BPSK modulation is analyzed, and the channel optimization proposal under the background of high precision signal reception is proposed. Finally, the research results are summarized, and the next step will be expected. This topic provides a theoretical support for the future of the high rail vehicle to get rid of the ground measurement and control network, and to realize the autonomous positioning and navigation of the high rail aircraft on orbit.
【学位授予单位】：国防科学技术大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：V448.2;TN967.1

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