Azimuth multichannel SAR signal adaptive reconstruction method

Abstract

The invention belongs to the field of radar technology, and discloses an azimuth multichannel SAR signal adaptive reconstruction method. The method comprises the steps of acquiring a two-dimensional spectrum of echo data which are received by each channel; obtaining a corresponding multichannel data matrix by means of the two-dimensional spectrum and obtaining a corresponding covariance matrix for each base band frequency in a base band frequency range; constructing a corresponding first guiding vector at each Doppler frequency in a Doppler frequency range, and furthermore calculating N Doppler spectrums at the Doppler frequency by means of the first guiding vector and a covariance matrix which corresponds with each base band frequency, determining a base band Doppler center and an effective Doppler bandwidth by means of N Doppler spectrums at each Doppler frequency, obtaining a fuzzy component number according to the base band Doppler center and the effective Doppler bandwidth at each base band frequency, and a signal matrix at the base band frequency is reconstructed by means of the fuzzy component number. The azimuth multichannel SAR signal adaptive reconstruction method can keep integrity of the Doppler spectrum and improves signal-to-noise ratio of the reconstructed signal.

Description

technical field [0001] The invention relates to the technical field of radar, in particular to an azimuth multi-channel SAR signal adaptive reconstruction method. Background technique [0002] The azimuth multi-channel Synthetic Aperture Radar (SAR) system has more degrees of freedom than the traditional single-channel SAR system. It uses spatial sampling to compensate for time sampling, which breaks through the minimum antenna area limit. It has excellent performance in resolution imaging. [0003] Since the Pulse Recurrence Frequency (PRF) of the azimuth multi-channel SAR system is smaller than the real Doppler bandwidth, the echo received by each channel of the azimuth multi-channel SAR system has Doppler ambiguity. Therefore, how to restore the unambiguous Doppler spectrum from the aliased Doppler spectrum is an important problem in the wide-range high-resolution imaging of the azimuth multi-channel SAR system. In recent years, people have done a lot of research and pr...

AI Technical Summary

Problems solved by technology

[0005] In view of the deficiencies in the above existing technologies, the embodiments of the present invention provide a signal adaptive reconstruction method for azimuth multi-channel SAR, which can effectively solve the problem that the traditional azimuth multi-channel SAR signal reconstruction method does not consider the change of the ambiguity component with the baseband frequency. and the problem of changing the number and position of fuzzy components caused by the known steering vector, not only can maintain the integrity of the Doppler spectrum, improve the signal-to-noise ratio of the reconstructed signal, but also estimate the Doppler spectrum during the reconstruction process. Le center, antenna pattern and other parameters

Images