Sonar moving target imaging method based on target echo Doppler characteristics

Abstract

The invention provides a sonar moving target imaging method based on target echo Doppler characteristics, which comprises the following steps of: performing band-pass filtering on echo data of each basic element in a receiving basic array; performing band-pass filtering on each frequency point signal to acquire band-pass data of each frequency point; performing quadrature demodulation on the datasubjected to band-pass filtering of each frequency point to acquire an analytic signal form of a real signal; performing Chebyshev weighting and focusing operation on the echo data subjected to quadrature demodulation of each frequency point; acquiring image data of each frequency point in a polar coordinate system by fast Fourier transform (FFT) beam forming; and performing interpolation mergingon the image data subjected to FFT beam forming of each frequency point, and converting an image in the polar coordinate system into an image which accords with the visual habit of people in a rectangular coordinate system by sector conversion. By the FFT beam forming, the method can be implemented by an FFT algorithm in digital signal processing, and the requirement of system real-time imaging is met.

Description

technical field [0001] The invention relates to a sonar imaging method, in particular to a sonar imaging method based on echo Doppler characteristics. Background technique [0002] The traditional two-dimensional sonar imaging method is time-delay beamforming. This method cannot define the beam in any direction. If you want to define the beam in a certain direction, the required ADC (that is, the analog signal to the digital signal Converter) has a high sampling frequency, requires a large amount of storage, and is difficult to implement in hardware. For the above shortcomings of delay beamforming, interpolation beamforming can be used to avoid high sampling rates. If you want to obtain ideal interpolation effects, the requirements for interpolation filters are relatively high, and the amount of calculation will be large. Contents of the invention [0003] The purpose of the present invention is to provide a sonar moving target imaging method based on target echo Doppler ...

AI Technical Summary

Problems solved by technology

[0002] The traditional two-dimensional sonar imaging method is time-delay beamforming. This method cannot define the beam in any direction. If you want to define the beam in a certain direction, the required ADC (that is, the analog signal to the digital signal Converter) has a high sampling frequency, requires a large amount of storage, and is difficult to implement in hardware

For the above shortcomings of delay beamforming, high sampling rate can be avoided by interpolation beamforming. If you want to obtain ideal interpolation effect, the requirements for interpolation filter are higher, and the amount of calculation will be huge.

Images