利用信号多特征的X射线脉冲星自主导航增强技术研究

X-ray pulsar navigation is on the basis of pulsar timing observation and has advantages over satellite navigation in spacecraft autonomous navigation, anti-interference and military need for navigation war, but its low navigation locating accuracy limits its application. The reason for this is that many stable physical properties of X-ray pulsar have not been fully used. So, this project analyzes the factors that influence the accuracy of X-ray pulsar autonomous navigation and studies the mechanism of improving X-ray pulsar navigation using X-ray pulsar radiation vectors、polarization observation and timing property; the project proposes a X-ray pulsar geometry navigation method using high accuracy radiation direction vector, which is combined with timing observation to promote the orbit determination accuracy of spacecraft; the project also studies the pulsar polarization information expression model and detecting method applied for navigation to decrease the error of pulsar timing and location; finally a posture acquisition method combining pulsar radiation vector with polarization information is proposed and determination of attitude information using single detector is achieved.. The achievements of the project provide new methods for improving the performance of X-ray pulsar autonomous navigation and the theory basis on and available way for the application of multiple pulsar characteristics..

X射线脉冲星导航以脉冲星计时观测为基础，在航天器自主导航、抗干扰以及应对导航战的军事需求等方面具有导航卫星系统所不具备的优越特性，但其较低的导航定位精度又制约着它的广泛应用。究其原因，主要是X射线脉冲星辐射信号的一些物理特性未能得到充分利用。为此，本项目将分析制约X射线脉冲星自主导航精度的主要因素，研究利用脉冲星辐射矢量和偏振等信号特征来提升脉冲星导航性能的机理；提出利用高精度辐射方向矢量的X射线脉冲星几何导航方法，并与计时观测结合以提高航天器自主导航精度；研究适用于导航的脉冲星偏振信息表示模型和测相方法，削弱脉冲星计时、定位误差；提出利用脉冲星辐射矢量和偏振信息实现单探测器观测单颗X射线脉冲星定姿。. 该项目成果为提升X射线脉冲星自主导航性能提供新的途径，并为脉冲星信号多个特征的导航应用提供理论依据和有效手段。

作为重要的备选自主导航技术，X射线脉冲星导航受到广泛关注。本项目从X射线脉冲星信号的多种特性出发，分析并提出增强X射线脉冲星导航精度的方法。利用X射线脉冲星信号的物理特性，研究了脉冲星信号不同的建模方法，来逼近真实信号，为算法研究提供数据。X射线脉冲星到达时间测量是脉冲星导航的基本输入，提出了直接序列测量准确估计脉冲星信号相位的方法。从利用辅助矢量信息出发，利用编队卫星之间的基线信息来增强X射线脉冲星导航的精度。针对脉冲星微弱信号处理、测距方法展开研究，提出了利用基于X射线测距和相关技术辅助增强XPNAV的方法，为修正深空探测机载时钟的误差，提出了利用脉冲星计时观测实现机载时钟守时的方法；针对利用单颗脉冲星实现卫星导航问题，提出了单脉冲星定轨的原理和方法；面向未来脉冲深空导航应用，提出利用脉冲星的到达时间和火星卫星的观测角结合的融合导航方法。所提出的方法为提高脉冲星导航精度提供了新的途径和方法。