利用TDOA和FDOA的单站多外辐射源目标定位算法

针对利用单个观测站接收多个外辐射源信号从而实现对运动目标定位的问题，以直达信号和目标回波信号之间的到达时差和频差为观测量，采用Taylor迭代方法，得到了目标位置和速度估计。迭代的初值由最小二乘方法得到。最后，推导了算法的克拉美罗界和理论误差。仿真结果表明，算法仅需1次迭代即可收敛至全局最优解；在一般测量误差条件下，算法的实际定位误差逼近克拉美罗界；对系统几何精度因子图的分析表明，目标及外辐射源位置也是影响定位精度的重要因素。

Single-observer Multi-illuminators Passive Location Using TDOA and FDOA Measurements

In order to locate a moving target with a single observer receiving signals from multiple illuminators, with the time differences of arrival (TDOAs) and frequency differences of arrival (FDOAs) between direct signals and target echoes as measurements, Taylor iterative method is used to estimate the target position and velocity. The initial iteration value is given by a least squares (LS) algorithm. The Cramer-Rao lower bound (CRLB) and the theoretical error of the proposed algorithm are also derived. Simulation results show that the proposed algorithm needs merely one iteration to converge to the global optimal solution. The CRLB of jointing TDOA and FDOA location system is lower that of the TDOA-only and FDOA-only system. Moreover, the proposed algorithm achieves the CRLB at moderate noise level before the threshold effect occurs. From the Geometric Dilution of Precision (GDOP) figure, we conclude target position and illuminator position are also important factors affecting the localization accuracy.