基于长基线干涉仪相位差的多站无源定位方法

针对常用多站无源定位技术存在时差(TDOA)/频差(FDOA)定位对超低旁瓣辐射源适应性差、测向(DOA)定位的造价成本和系统复杂度高等缺点，该文提出了一种基于相位差(PDOA)的多站无源定位新体制，利用每个观测站上至少两个接收天线和通道构成的长基线干涉仪(LBI)，通过测量辐射源信号到达长基线干涉仪天线的相位差实现定位。针对相位差的2π模糊引入的非线性和非连续性，提出了一种基于多假设迭代优化的定位方法，首先利用一组相位差确定多个可能的辐射源位置初始值，然后采用高斯-牛顿(GN)方法对每个位置初始值进行迭代优化并计算代价函数，最后选择具有最小代价函数的估计值作为最终的定位结果。该方法可获取稳健的迭代初始值，算法运算量适中。仿真结果表明该定位方法的均方根误差(RMSE)在高斯观测噪声条件下可达到克拉美罗下限(CRLB)。

Passive Localization by Multiple Observers Based on the Phase Difference of the Arrival of a Long Baseline Interferometer

The deficiencies in the commonly used passive localization technologies using multiple observers are the failure of the emitter with a very low sidelobe based on the Time Difference of Arrival (TDOA)/ Frequency Difference of Arrival (FDOA) and the high cost and system complexity based on the Direction of Arrival (DOA), a novel passive localization system based on the Phase Difference of Arrival (PDOA) is presented. Herein, a Long Baseline Interferometer (LBI) comprising at least two sets of the receiving antenna and channel on each observer is used to measure the PDOA and locate the emitter. Moreover,to solve the nonlinearity and discontinuity caused by the 2π ambiguity, an iterative optimization method based on multiple hypotheses is proposed. First, a pair of PDOA is selected to obtain multiple initial values; Second, the Gauss-Newton (GN) method is applied to update each initial value; Finally, the cost function corresponding to the updated estimate is calculated. The result with the minimum cost function is selected as the final estimate. The initial values of the emitter position can be robustly obtained with moderate computational complexity. Simulation results show that the Root Mean Square Error (RMSE) of the proposed method can reach the Cramer-Rao Lower Bound (CRLB) at moderate Gaussian measurement noise.