Array beamforming method by quickly expanding and dragging broadband frequency domain

Abstract

The invention provides an array beamforming method by quickly expanding and dragging a broadband frequency domain. The method combines ETAM passive synthetic aperture technology and a broadband frequency domain beamforming method, and comprises the following steps of: 1) receiving space signals with a linear array to acquire time domain signals of M array elements; and taking number of overlappedarray elements as N; 2) carrying out fast Fourier transform on k snapshot and k+1 snapshot data in a time domain; 3) determining frequency band range of target radiation signals, and calculating phase shift parameters according to the overlapped array elements of any two adjacent snapshots; 4) carrying out phase compensation on different frequency components respectively to acquire virtual synthesized array elements; 5) repeating the steps, and carrying out K times of aperture synthesis; 6) carrying out FFT transform on zero filling of the synthesized array element signals in a spatial domain, and then transferring zero frequency components of the acquired data to a spectrum center; 7) calibrating each frequency point to acquire beam output of different frequency points; and 8) synthesizing beamforming results of different frequencies so as to realize accurate positioning of targets.

Description

technical field [0001] The invention belongs to the field of sonar digital signal processing, and in particular relates to a fast broadband frequency domain extended towed array beamforming method. Background technique [0002] Passive Synthetic Aperture (PASA) is a technology that passively receives target noise and artificially increases the length of a small aperture array through array motion and signal processing methods, allowing people to rely on short array maneuvers to obtain various benefits of long arrays. Today, passive sonar has been widely used in many naval systems, such as towed arrays, broadside arrays, fish sonars, and submarine line arrays, etc., mainly used to locate, detect, classify, or track targets. In recent years, with the increasing attention paid to passive synthetic aperture, its performance has been continuously enhanced. [0003] Existing positioning is mainly realized by beamforming, which utilizes the time difference between target signals a...

AI Technical Summary

Problems solved by technology

[0010] Overall, the ETAM algorithm has incomparable performance advantages over the FFTASA algorithm, but the calculation speed is slow and the feasibility is not high

Images