多子阵子空间拟合波达方向估计

提出了考虑阵元互耦的子空间拟合波达方向估计方法。用一带状、对称Toeplitz矩阵对均匀线阵的互耦矩阵建模。根据互耦矩阵自由度,去除部分两边阵元,研究了子空间拟合算法中ESPRIT算法的理论性能。在大快拍的情况下,均匀线阵的MCLS-ESPRIT算法的角度估计误差是一个零均值的联合高斯分布,同时给出了分布的协方差表达式。由方差的数值计算可知,在阵元数和信源数确定的情况下,存在估计标准差最小的子阵;与不存在互耦的理想情况相比,除了估计标准差少许增加外,性能接近。本文的方法已应用于高分辨率测深侧扫声呐,获得了好结果。在声呐阵阵元数增加的条件下,用本文的方法,能抑制均匀线阵的互耦的影响。

Estimating the directions of arrival based on multi-subarray subspace fitting

A multi-subarray subspace fitting method, which considers mutual coupling among array elements, to estimate the directions of arrival is presented. The mutual coupling matrix of uniform linear arrays is modeled with a banded symmetric Toeplitz matrix. According to the freedom of mutual coupling matrix, part of the array elements at the two sides is neglected. The theoretical characteristics of ESPRIT algorithm, one of the subspace.fitting algorithm, are studied. For large N and uniform linear array, the MCLS-ESPRIT estimation error is asymptotically jointly Gaussian distributed with zero means, and its covariances is obtained. It is known from the simulation that there exists a subarray with lowest estimation error for certain number of the array elements and the signal sources, and its performance of estimating the directions of arrival is close to the ideal situation when mutual coupling does not exist while its variance has some increase. The method presented in this paper has been applied in high resolution bathymetry sidescan sonar and good results are obtained. At the cost of increasing the number of the array elements, the method presented in this paper can reduce the affection of the mutual coupling among array elements.