中文摘要：

为了提高分布式阵列在低信噪比（signal-to-noise ratio，SNR）条件下的波达方向（direction-of-arri-val，DOA）估计性能，同时放宽阵列物理孔径扩展程度的限制，提出了一种基于旋转不变子空间（estimation of signal parameters via rotational invariance techniques，ESPRIT）的多基线分布式阵列 DOA 估计方法。该方法通过优化分布式阵列结构，在子阵间使用多基线结构布阵，结合 ESPRIT 算法和多步解模糊方法得到多基线分布式阵列的高精度无模糊 DOA 估计。此外，利用最大后验概率准则近似法分析分布式阵列 DOA 估计的门限效应，给出了 SNR 门限和基线长度门限的近似计算方法。计算机仿真结果验证了所提方法的有效性。

英文摘要：

In order to improve the accuracy of direction-of-arrival （DOA）estimation with distributed arrays in a low signal-to-noise ratio （SNR）scenario,and to loosen the restrictions on array aperture extension,a DOA estimation method based on estimation of signal parameters via rotational invariance techniques （ESPRIT）is proposed for multi-baseline distributed arrays.The configuration of the distributed array is firstly optimized to obtain multi-baseline subarrays.Then high accuracy and unambiguous DOA estimates are obtained by the com-bination of ESPRIT algorithm and the multi-step disambiguation method.Moreover,the threshold effect on the DOA estimation method is analyzed via the maximum a posteriori criterion.Furthermore,approximate methods for SNR threshold and baseline threshold calculations are presented.Finally,simulation results are given to verify the effectiveness of the proposed method.