基于标校源辅助的不相交多目标到达时差定位

TDOA localization of multiple disjoint sources based on a calibration emitter

鉴于定位站位置误差会极大地降低多站无源定位的目标定位精度,提出了一种标校源辅助的不相交多目标到达时差(TDOA)闭式定位算法。该算法首先使用标校源减小定位站位置误差,并估计对应的误差统计特性,然后使用更新的定位站位置,利用两步加权最小二乘(TS-WLS)算法实现不相交多目标的高精度TDOA定位。通过克拉美罗界(CRLB)推导,从理论上分析了该闭式定位算法的定位性能;通过仿真实验,验证了标校源校正技术可提高对多目标的定位精度,并且在较小的TDOA观测误差和定位站位置误差下,对多目标的定位性能可以达到CRLB。该算法不需要初始值估计和迭代运算,同时避免了定位站和目标位置的联合估计,计算量较小。

The passive source localization accuracy can be greatly reduced due to the sensor position error. A localization algorithm using time difference of arrival（TDOA） for multiple disjoint sources was proposed,which improves the localization accuracy by means of a single calibration emitter. The sensor position error was first reduced by using the calibration emitter,and the corresponding error statistical knowledge was estimated. Then based on the updated sensor position,TDOA localization of multiple disjoint sources with high accuracy was realized by utilizing the algorithm of two-step weighted least squares（TS-WLS）. The CramerRao lower bound（CRLB） was theoretically derived to analyze the localization performance of the closed-form algorithm. And the theoretical derivation was validated by the simulations. The simulation results indicate that the localization accuracy of multiple disjoint sources is obviously improved by using calibration correction technique. Moreover,the solution performance is shown to reach the CRLB under small TDOA observation error and sensor position error. The developed estimator is computationally attractive because it does not require initial solution estimation and iterative computation. Furthermore,joint estimation between source positions and sensor positions is not needed,which reduces the calculation amount.