考虑相对论效应的火星探测器天文测角导航

Celestial Angle Measurement Navigation for Mars Probe Considering Relativistic Effect

针对广义相对论效应使恒星发出的星光在经过大质量天体时发生一定程度的偏折,狭义相对论使高速运行的航天器能够观测到恒星光行差,这两者会造成航天器实际采集到的量测量与星历中对应的信息不符,进而影响导航精度的问题,提出一种考虑相对论效应的天文测角导航方法。通过对星光角距量测模型进行相对论效应修正,使其符合实际观测结果,以提高导航精度。仿真结果表明,在火星环绕轨道,提出的方法可有效修正相对论效应对航天器测角导航造成的影响。当星敏感器量测误差为3",火星敏感器量测误差为0.05°时,修正后的平均位置和平均速度误差相比于未修正的情况分别减少了13.97%和13.89%。

Celestial navigation based on star angle is a classical autonomous navigation method for spacecraft.By measuring the angular relationship between spacecraft,near celestial bodies and background stars,the current position and velocity information of spacecraft can be deduced.However,the effect of general relativity causes the starlight from a star to be somewhat deflected as it passes through a massive object,and special relativity allows high-speed spacecraft to observe stellar aberration.These two factors will cause the difference between the actual measurement of spacecraft and the corresponding information in the ephemeris,and then affect the navigation accuracy.To solve this problem,a celestial navigation method considering relativistic effect was proposed in this paper.The star angle measurement model is correct by relativistic effect to conform to the actual observation result,so as to improve the navigation accuracy.The simulation result shows that the proposed method can effectively correct the influence of relativistic effect on spacecraft star angle navigation in Mars surrounding orbit.When the star sensor measurement error is 3"and the Mars sensor measurement error is 0.05°,the corrected average position error and average velocity error are reduced by 13.97% and 13.89% respectively,compared with the uncorrected case.