【摘要】 针对利用运动接收机对静止超视距短波无线电目标定位的问题，提出了一种基于极大似然准则的天波超视距直接定位算法，进一步应用引力搜索算法，以实现高效的目标位置估计。推导了在上述问题中目标位置估计的克拉美罗下界(Cramér-Rao lower bound, CRLB),并分析了所提算法的计算复杂度。仿真实验结果表明，与传统的针对视距目标的直接定位算法相比，所提出的算法能显著提高对天波超视距短波目标定位的精度，且性能非常接近CRLB;相比于对应的网格搜索算法，在保持较高定位精度的同时，所提算法具有更高的计算效率。更多还原

【Abstract】 The localization of stationary over-the-horizon(OTH) emitters which transmit shortwave signals is considered utilizing receivers mounted on fast moving platforms. To tackle the above problem, first, a direct position determination(DPD) algorithm was proposed for sky-wave OTH emitters based on the maximum likelihood(ML) criterion. Further, the gravitational search algorithm(GSA) was applied to achieve the efficient calculation in the emitter position estimation. Furthermore, the associated Cramér-Rao lower bound(CRLB) of the OTH emitter position estimation and the computational complexity of the proposed algorithm were analyzed to evaluate the performance of the proposed algorithm. Illustrative simulation results have demonstrated that compared with the traditional DPD algorithm which is applied to locating line-of-sight emitters, the performance of the proposed algorithm is close to the associated CRLB. Additionally, compared with the corresponding grid search algorithm, the proposed algorithm is of higher computational efficiency while maintaining superior localization performance.更多还原