Target direction-finding method based on acoustic vector two-dimensional nested array

The invention discloses a target direction-finding method based on an acoustic vector two-dimensional nested array, and is used for direction and pitching measurement of an underwater target. The method includes building a new acoustic vector two-dimensional nested array which is formed by two two-dimensional acoustic vector subarrays nested in geometric position, array elements of the subarray 1 are distributed in sparse grids, array elements of the subarray 2 are distributed in dense grids, two grids can be selected arbitrarily, that a matrix that associate the grids is an integer matrix is required only, the integer matrix can also be selected freely, then an autocorrelation matrix of signals output by the array are utilized to build a difference synthesis acoustic vector two-dimensional array, and finally a three-dimensional smooth DOA algorithm is utilized to obtain second-order statistics of received signals of the difference synthesis acoustic vector array.