航天器自主天文导航系统的可观测性及可观测度分析

天文导航系统中的观测量是一个重要的精度影响因素,星光角距和星光仰角是天文导航中两种最常用的观测信息,首先介绍了这两种观测信息及其量测方程的建立,然后从天文导航系统的可观测性和可观测度的角度,以观测矩阵的条件数作为系统可观测度的度量标准,分析了由于所选用的观测量的不同所导致的系统导航性能的差别,同时给出了一种衡量天文导航系统中的观测量和系统性能的分析方法.计算机仿真结果证明了该方法的有效性.

Analysis of observability and the degree of observability in autonomous celestial navigation

The type of celestial measurement used in the autonomous celestial navigation system is one of the most important factors, which effect the precis ion of position determination greatly. There are two main celestial measurements . One is the angle between the lines of sight to a star and earth core. The othe r is the star elevation angle which is the angle between the lines of sight to a star and the edge of earth disk. These two common celestial measurements and th eir measurement equations were presented. The performance of the s ystem using different kind of celestial measurement was analyzed based on the ob servability and the degree of observability of the celestial navigation system. The condition number of the observability matrix is adopted as a scalar measure of degree of observability. The effectiveness and the validation of this analysi s method were confirmed by the results of computer simulation.