ACTA AERONAUTICAET ASTRONAUTICA SINICA >
Received date: 2024-04-22
Revised date: 2024-04-22
Accepted date: 2024-05-09
Online published: 2024-06-03
A refocusing algorithm for post-processing defocused images is proposed to address the problem of defocusing in Synthetic Aperture Radar （SAR） imaging results caused by translational motion of the target. Firstly， in response to the problem that the spatial variation of the Taylor expansion coefficient of the target’s slant range spatially with the target’s azimuth will result in the loss of azimuth invariance， an equivalent slant range model with non spatially varying coefficients is proposed. This slant range model can weaken the phase error caused by time domain range walk correction in squint imaging. Secondly， to address the mismatch of frequency domain compensation function caused by Doppler ambiguity and the different residual phase forms in different SAR algorithm results， the frequency domain truncation and inverse matching methods are used to obtain the equivalent echo data after Doppler center correction. Finally， the residual phase is estimated and compensated using the minimum entropy autofocus method， resulting in a focused image. The effectiveness of the proposed algorithm is verified through simulation experiments.
Li YAN , Jie ZHANG , Jiadong WANG . [J]. ACTA AERONAUTICAET ASTRONAUTICA SINICA, 2024 , 45(S1) : 730559 -730559 . DOI: 10.7527/S1000-6893.2024.30559
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