深空天文测速导航方法以空间中的某颗恒星为目标,利用航天器自身携带的光谱仪测量相对于恒星的移动速度来实时调整自行速度和路线。太阳是主要的测速导航源之一,利用目前运行的空间卫星的光谱观测资料,分析和研究了太阳相对于卫星的视线速度和速度误差变化情况,为本项目中自主导航光谱提供实测证据。选取了太阳表面5个位置的光谱观测,持续时间在一个小时左右,通过高斯谱线轮廓拟合观测数据,得到了太阳表面5个位置的亮度变化、谱线宽度和速度,其中主要参数速度平均值大约在10 km/s,和速度变化在3 km/s。这是由太阳表面存在大量的微观尺度上的物质运动所导致的。
The main idea of autonomous navigation based on velocity measurement is to detect the on-sight speed of the star in the space when the satellite sees it using the spectrograph. The Sun is one of the most important observation targets in space. In this paper, we analyze the data of the space-born spectrograph to observe the Sun at five different positions. Each data set has a period of about one hour. Using the Gaussian profile fitting, we can get the intensity, width and speed. The mean speed is about 10 km/s with a standard deviation of 3 km/s, which is caused by the small scale activities on the solar surface.