An adaptive and efficient imaging method for spaceborne squint sliding-spotlight SAR based on chirp scaling

doi:10.7523/j.ucas.2025.022

Abstract

Abstract: To address the contradiction between computational efficiency, imaging quality, and azimuth bandwidth in existing algorithms, this paper proposes an adaptive and efficient sliding-spotlight SAR imaging method based on chirp scaling. Sliding-spotlight SAR, as an important imaging mode, combines the advantages of high resolution and wide azimuth bandwidth. However, current methods face the problem of high computational complexity when dealing with wide azimuth bandwidths, and severe range-azimuth coupling issues under large squint angles. Therefore, this paper introduces a chirp scaling processing mechanism based on the traditional two-step imaging algorithm and combines range walk correction techniques to effectively solve the severe range-azimuth coupling problem in squint sliding-spotlight mode, significantly improving imaging efficiency. Experimental results show that the proposed method achieves good imaging results in both side-looking and squint sliding-spotlight modes and demonstrates higher computational efficiency under wide bandwidth conditions. Additionally, by comparing the imaging performance under different azimuth bandwidths in squint conditions, the adaptability of the proposed method under wide bandwidth conditions is verified, providing an effective solution for wide-swath imaging at large squint angles.

Key words: sliding-spotlight SAR, large squint angle, chirp scaling, adaptive and efficient algorithm

CLC Number:

TN959.73

ZHANG Yunju, SHANG Mingyang, LV Yini, QIU Xiaolan. An adaptive and efficient imaging method for spaceborne squint sliding-spotlight SAR based on chirp scaling[J]. Journal of University of Chinese Academy of Sciences, DOI: 10.7523/j.ucas.2025.022.

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