Target depth information extraction method and system based on modal wave number spectrum transformation

The invention relates to the ocean field and the sonar signal processing field, and especially relates to a target depth information extraction method and system based on modal wave number spectrum transformation. The method comprises the following steps: performing phase difference compensation and accumulation processing on data received by each array element of a horizontal towed line array by using a modal domain beam forming method so as to obtain modal wave number spectrum data of a target radiation signal; performing transformation processing on the modal wave number spectrum data of the target radiation signal to obtain modal wave number spectrum transformation data containing a target depth information value; and carrying out peak value judgment on the modal wave number spectrum transformation data, and extracting target depth information to obtain the target depth. According to the method, the depth values of the horizontal towed line array and the target sound source are visually displayed through