Array element domain fused large-aperture sonar array DEMON spectrum estimation method

The invention relates to a large-aperture sonar array DEMON spectrum estimation method based on array element domain fusion. The method comprises the following steps: firstly, analyzing a DEMON spectrum of data received by each array element of a sonar array; then, a correlation coefficient matrix is calculated based on an array element domain DEMON spectrum analysis result, the maximum correlation subarray length is estimated, an estimated value of the array element domain DEMON spectrum analysis result at each frequency point is obtained through a histogram statistical algorithm, and a continuous spectrum in the DEMON spectrum estimated value serves as an array element domain DEMON spectrum detection threshold; and finally, screening signal components in each array element domain DEMON spectrum analysis result by using an array element domain DEMON spectrum detection threshold, counting the number of array elements of each frequency point passing through the detection threshold, and comparing the maximum co