采用DIRECT算法的外辐射源雷达高效直接定位方法

针对直接定位目标函数为非凸函数，传统凸优化方法难以获得全局最优解，而常用网格遍历搜索方法运算量大的问题，提出采用DIRECT (Dividing rectangles)算法进行高效求解的方法。首先建立外辐射源雷达接收信号模型，在此基础上推导最大似然直接定位目标函数，为解决该目标函数非凸难以快速获得全局最优解的问题，将DIRECT算法用于目标位置的快速估计, 并理论分析其计算复杂度。数值仿真表明新方法计算速度快且定位精度高，相比网格遍历法，计算时间降低2个数量级，相比遗传算法降低1个数量级。 

An efficient method of direct position determination of passive radar with DIRECT algorithm

Traditional convex optimization method cannot find the global maximum since the object function of the direct position determination (DPD) is non-convex, thus, the exhaustive search is usually applied to find the global maximum inefficiently. An efficient method of position estimation with DIRECT (Dividing rectangles) algorithm is employed to solve this problem. Firstly, the received signal model of passive radar with opportunistic illuminator is built, and the object function of DPD is derived with maximum likelihood criterion. Then the DIRECT algorithm is employed to estimate the target position effectively in order to solve the problem that the object function is non-convex and difficult to obtain the global optimal solution, and the computational complexity is analyzed theoretically. Simulation results show that the proposed algorithm can estimate the target position efficiently with high accuracy, and its computation cost is less by two orders of magnitude than the grid search method, and less by one order of magnitude than genetic algorithms.