大气折射对高程约束下时差定位误差的影响及修正

电波在不均匀大气中传播会发生折射现象,传播路径和速度都会发生改变,若不考虑其影响,将导致利用测量多站到达时间差进行辐射源定位产生较大误差。本文分析了已知先验高程约束条件下大气折射对多站时差定位误差的影响,论证了迭代修正法在高程约束条件下(约束条件为冗余条件)无法达到最优,提出了大气折射条件下基于迭代然后再进行改进粒子群优化的时差定位误差修正算法,通过仿真分析验证了该修正算法的有效性。

Influence analysis of atmospheric refraction on elevation-constrained TDOA source localization error and its correction

Due to the inhomogeneity of the atmosphere, radio waves are subjected to refraction during the propagation process, which reduces its propagation speed and bends the propagation path. If this refraction effect is not taken into account when the source is localized through conventional multi-station time difference of arrival (TDOA)-based methods, a large localization error will occur. In this paper, the influence of atmospheric refraction on the TDOA localization error under the known elevation constraint is analyzed. It is proved that the iterative correction method cannot achieve the optimum under this elevation constraint (the constraint conditions are redundancy conditions). Consequently, a new atmospheric refraction correction method is proposed where iterative methods are applied to obtain initial solutions, which are further refined by improved particle swarm optimization (PSO) methods. The effectiveness of the proposed method is validated through simulation results and analyses.