脉冲星导航的整周模糊度解算方法研究

Study on Methods of Ambiguity Resolution for the X-Ray Pulsar Navigation System

脉冲相位是X射线脉冲星导航方法的基本观测量,在测量的脉冲相位与预报相位比对的过程中存在整周期模糊度问题.借鉴GPS载波相位模糊度的解算方法,提出了单差搜索法、最小二乘搜索法和模糊度函数法3种空间搜索方法用以解算脉冲星导航系统的整周模糊度,并针对地球卫星完全迷失的情况进行了搜索仿真验证.结果表明,这3种方法都能够准确地解算出整周模糊度,均可用于脉冲星导航系统的在轨解算.其中最小二乘搜索法的性能稳定,搜索速度快;模糊度函数法搜索速度慢,但适用于装配单X射线探测器的脉冲星导航系统.

Ambiguity resolution is one of the most important parts in the X-ray pulsar navigation system. Three space searching methods, as single-difference measurement search approach, least squares ambiguity search technique （LSAST） and ambiguity function method, are presented with the GPS carrier phase ambiguity resolution as a reference. A simulation is taken for the situation of loss of position in the earth orbit. The computer simulation results demonstrate that all the three ambiguity resolution methods are available to the X-ray pulsar navigation system. The further analysis shows that performance and searching speed using LSAST are better than other methods, and the ambiguity function method is suitable for the X-ray navigation system equipped with a single detector.