基于Walker星座的导航卫星自主导航的GDOP最小值分析

Analysis of GDOP Minimum Value for Autonomous Navigation Based on the Walker Constellation

卫星自主定轨时选择测量卫星的几何构型对于定轨精度有着重要的影响。目前地面接收机与导航卫星的几何构型对定位精度的影响主要由GDOP(几何衰减因子)来衡量,GDOP值的下限限制了在一定的测量精度下用户定位的精度范围。通过构建Walker构型的导航星座将地面接收机GDOP取最小值时的边界确定,推广应用到自主导航环境下,利用均匀采样和遗传算法分别独立得到GDOP的最小值,同时用仿真数据验证了这个值的正确性。

Geometry of measuring satellites has important implications for precision of the autonomous orbit determination. Currently, the affecting of the geometry for terrestrial receiver and a navigation satellites on the positioning precision are measured mainly by the GDOP. The lower limit of GDOP limits the measurement accuracy of a positioning accuracy range of the user. Constructing navigation constellation of Walker configuration determines the boundaries for taking the minimum value of GDOP of the terrestrial receiver. To promote the use of autonomous navigation environment, uniform sampling and genetic algorithms are used get the minimum GDOP independently. Simultaneously, the simulation data verfies the correctness of the minimum GDOP.