利用外辐射源的单站TDOA-FDOA定位方法

Single-Observer TDOA-FDOA Passive Location Using Illuminators of Opportunity

针对利用单站外辐射源的目标无源相干定位问题,提出了一种联合时差(TDOA)和频差(FDOA)的定位方法,推导了目标位置和速度的最大似然解。与一般最大似然估计方法不同,算法不存在搜索求解的巨大计算量和迭代求解的初值依赖问题。另外,推导了算法的克拉美罗界(CRLB)和理论误差。仿真结果表明,联合TDOA和FDOA定位方法的定位精度优于TDOA定位方法,在测量误差较大时,算法的估计误差仍能逼近CRLB。对几何精度因子图的分析表明,目标位置、辐射源数量及位置也是影响定位精度的重要因素。

This paper investigates target location with single-observer passive coherent location （PCL） system using illuminators of opportunity. A location method joining the time differences of arrival （TDOAs） and frequency differences of arrival （FDOAs） is proposed and the maximum likelihood （ML） solution of target position and velocity is derived. Unlike the general maximum likelihood approach, the proposed algorithm avoids the tremendous computation of global searching or the dependence on initial solution of iteration algorithm. Furthermore, the Cramer-Rao lower bound （CRLB） and the theoretical error of the proposed algorithm are also derived. Simulation results show that the localization accuracy of the joint TDOA and FDOA method proposed is higher than that of TDOA-only method. The localization error of the proposed algorithm approaches the CRLB at rela- tively high noise level. Moreover, from the geometric dilution of precision （GDOP） figure, we conclude target position, illuminator number and position are also important factors affecting the localization accuracy.