星载干涉仪无源定位新方法及其误差分析

A novel method for satellite-borne passive localization using interferometer and its error analysis

针对传统单星二维干涉仪测向定位存在的设备量大、易受通道间幅度/相位不一致性影响等缺点,提出了在单颗自旋卫星上只安装两个接收通道构成一维干涉仪,测量相位差变化率的无源定位新方法,采用了基于粒子群优化(PSO)的定位算法,分析了干涉仪转速以及旋转平面对定位性能的影响。结果表明,增大干涉仪转速有利于提高定位精度,为了使星下点周围各个方向上都有较好的定位精度,干涉仪旋转平面应与初始观测时刻卫星位置矢量垂直,PSO算法的定位精度能够接近定位误差的克拉美罗下限(CRLB)。

The conventional line-of-sight （LOS） geo-location method using two-dimension interferometer on a satellite leads to heavy payloads and it is always under the effect of amplitude-phase inconsistencies among receiving channels. A novel passive localization method is proposed, which merely needs two receiving channels to form a one-dimension intefferometer on a spin-stabilized satellite. Rate of phase difference change was measured for emitter localization. A location algorithm based on particle swarm optimization （PSO） was designed. The impact of rotating speed and rotating plane of the interferometer on localization precision was analyzed. The results showed that localization precision can be improved by increasing rotating speed of the interferometer, the rotating plane should be perpendicular to the satellite position vector at the initial moment in order to get good localization precision in all directions around satellite projection point on the ground, and localization precision of the proposed algorithm can approach the Cramer-Rao lower bound （CRLB）.