多运动站异步观测条件下的直接定位算法

摘要

针对多运动站无源融合定位系统中的异步观测问题，该文提出一种基于空间谱分析的直接定位算法。首先利用子空间分析理论建立异步观测直接定位模型，构造多站协同定位联合空间谱函数，采用多级搜索方法实现定位解算。然后推导了该算法的定位误差协方差矩阵及克拉美罗下限。最后对该算法在异步观测条件下的定位性能进行蒙特卡洛仿真。仿真结果表明算法定位精度能够逼近克拉美罗下限，定位性能优于基于定位参数的分步定位算法，尤其在低信噪比情况下优势更明显。%A Direct Position Determination (DPD) algorithm based on spatial spectrum analysis for the issue of asynchronous observation in the multiple moving sensors passive fusion location system is proposed. At first, a direct determination mathematical model of the asynchronous scene is constructed and a multiple sensors cooperative spatial spectrum function is composed. Furthermore, the position of the emitter can be got by a two or three dimensional search, and then the derivations of the estimators’ variance and the Cramer-Rao Lower Bound (CRLB) are given. Finally, the Monte Carlo simulations over the asynchronous scene indicate that the accuracy of the proposed method is close to the Cramer-Rao lower bound and superior to the two-step location method based on the location parameters, especially in the low SNR.