双星时差频差联合定位方法及其误差分析

A Method of Dual-Satellites Geolocation Using TDOA and FDOA and Its Precision Analysis

针对两个卫星联合利用信号到达时间差(TDOA)、到达频率差(FDOA)信息对地面已知高度固定辐射源定位的问题,提出了一种获得目标三维位置解析解的方法,不仅可得到卫星运动方向与卫星间连线方向不同时的解,而且可得到在两者方向相同时的解。在观测参数存在误差条件时对双星定位误差几何稀释(GDOP)分布理论和Monte-Carlo仿真分析基础上,得到了定位误差的解析表达式。分析结果表明为了减少定位误差大的区域,双星的运动方向最好与卫星间连线方向一致或接近。

To solve the problem of locating the fixed emitter with known altitude by dual satellites using time difference of arrival （TDOA） and frequency difference of arrival （FDOA） information, an analytic solution in three dimensional spaces is presented. This method could get the solution not only when the direction of satellites moving is different from the directions of two satellites line, but also get the solution when the directions are the same. Its geolocation error is analyzed in theoretically as well as by Monte-Carlo simulation. And the analytic statement of location error was got. The analysis reviewed that the direction of dual-satellites had better be parallel to the line of two satellites to make large location error area smaller.