三元阵被动定位中时延差估计算法研究

为了提高三元阵被动定位精度，该文对互谱法时延差估计进行了研究改进。改进算法解决了单独采用互谱法进行时延差估计存在的相位模糊问题，增强了互谱法在实际应用的鲁棒性。该算法所得时延差由周期值和修正值构成；时延差周期值是通过对阵元间互谱信号进行时延补偿所得，时延差修正值是采用最小二乘法对补偿后互谱信号拟合所得。理论分析和实验结果表明:采样率为103 Hz时的时延差估计精度可以达到10-6 s，该方法具有很强的实用性。能有效提高三元阵被动定位精度。

Investigation on Time Delay Difference Estimation for Three-element Array Passive Positioning

In order to improve the passive positioning accuracy of three-element array, a modified cross- spectral algorithm is proposed for time delay difference estimation. The improved method solves phase ambiguity issue in conventional the cross-spectral method, and enhances the robustness of cross-spectral method in practical application. The time delay difference obtained with the proposed method contains cycle value and correction value. The cycle value is obtained by compensating the phase of cross-spectrum signal, and the correction value is obtained by applying least-squares to cross-spectrum signal after compensation. Theoretical analysis and experiment results show that this method can achieves the evaluation accuracy of10-6 s for sampling rate of 103 Hz, and has a strong practicability. Therefore it can effectively improve the positioning accuracy of three-element array passive positioning.