基于GNSS的无源雷达定位能力分析

基于全球导航定位系统(GNSS)的无源雷达是当前研究的热点。在基于距离和的定位方法中，GNSS自身的时间同步误差和定位误差会降低定位精确度，考虑这些误差并结合全球四大GNSS的信号特性和参数测量能力，推导了三维空间多发多收距离和定位精确度表达式以及克拉美罗下界(CRLB)。选取不同卫星和接收站数量进行了仿真分析，揭示了卫星数量、接收站数量与定位精度之间的关系。当忽略卫星位置误差时，接收站数量增长带来的定位精确度增长百分比对于任意辐射源数量为定值；若卫星位置误差增大，增加接收站数量对于定位精确度的改善程度会降低。所得结论可以为基于GNSS的无源雷达辐射源选取与接收站布站提供理论参考。

Localization ability analysis of GNSS-based passive radar

Global Navigation Satellite System(GNSS)-based passive radar is a hotspot of current research. In the positioning method based on the sum of distance, the time synchronization error and positioning error of GNSS will reduce the positioning accuracy. Considering the above errors and combining the signal characteristics and parameter measurement capabilities of the four major GNSSs in the world, the three-dimensional localization accuracy expressions and the Cramer-Rao Lower Bound(CRLB) for the system of multi-transmit multi-receive are derived. Through simulation analysis, the relationship between the number of satellites or receiving stations and the localization accuracy is revealed. When the satellite position errors are ignored, the percentage increases in localization accuracy caused by the number increases of receiving stations are the fixed values for any number of radiation sources; if the satellite position errors increase, the improvement in positioning accuracy by increasing the number of receiving stations will decrease. The obtained conclusions can provide a theoretical reference for the selection of GNSS-based passive radar radiation sources and the deployment of receiving stations.