一种适用于机场场面MLAT监视系统的定位算法及其性能分析

A location algorithm suitable for MLAT surveillance system at airport surface and its performance analysis

与通常的三维目标不同,机场场面目标的高度是已知固定值,这点在设计应用于民用机场场面监视的无源多点时差定位(MLAT)系统时应予以考虑。基于机场场面目标及MLAT系统的特点,提出了一种改进的时差定位算法,该算法特别适合应用于场面监视的MLAT系统中。相比于传统的三维定位算法,该算法不但可以提高定位精度,还可增强系统的鲁棒性。给出了该改进时差定位算法的克拉美罗界(CRLB),并进一步推导出了该算法与三维定位算法精度之间的理论关系,从理论上证明了该算法的定位精度高于三维定位算法。与此同时,基于条件数理论还证明了该算法的鲁棒性优于三维定位算法。仿真实验及实测数据证明了所得结论的正确性和有效性。

Instead of regular three-dimensional targets, the height of targets at airport surface is a known constant and it should be considered when designing an multilateration （MLAT） system suitable for surveillance at civil airport surface. Based on the characteristics of target at airport surface and MLAT, we propose a modified time of difference arrival （TDOA） positioning algorithm, which is especially useful for MLAT system for the airport surface surveillance. Compared with traditional three-dimensional positioning way, the proposed algorithm not only improves the positioning accuracy but also gets greater system robustness. A corresponding Cramer-Rao lower bound（CRLB） of this algorithm is achieved, and the theoretical relation between two-dimensional and three-dimensional positioning algorithms is deduced, which further proves that the algorithm has higher precision than three-dimensional way. Meanwhile we use condition number theory to prove that the proposed algorithm has stronger robustness than three-dimensional positioning way. The simulation and practical measured data verify the correctness and effectiveness of the above conclusions.