A Fast Time-Domain Imaging Algorithm for High-Squint Diving Maneuvering Platform SAR Based on Modified Hybrid Coordinate System

The multi-stage sub-image merging is a key method to accelerate to synthetic aperture radar (SAR) imaging in the time domain. However, the high-squint acquisition in the maneuvering platform enhances the irregularity of the support region of the spectrum, which degrades the performance of image merging in efficiency and accuracy. Because of these issues, in this paper, a modified hybrid coordinate system is designed, based on which a fast time domain imaging algorithm is developed for high-squint diving maneuvering platform SAR. Benefiting from the equivalent slant range model in the modified hybrid coordinate system, the sensitivity of the spectrum to the squinted angle is reduced, and the space variation phenomenon of the spectrum is eliminated. Hence, the spectral preprocessing function can be easily designed to effectively compress and merge the spectrum, which improves the performance of the image merging in efficiency and accuracy. Both simulated and raw data are processed to validate the performance superiority of the proposed algorithm. © 2024 Chinese Institute of Electronics. All rights reserved.