为解决现有算法在计算效率、成像质量和方位幅宽之间的矛盾,本文提出一种基于Chirp变标的自适应高效滑动聚束合成孔径雷达（synthetic aperture radar,SAR）成像方法。滑动聚束SAR作为一种重要的成像模式,兼顾了高分辨率与宽方位幅宽的优势,但现有方法在处理大方位幅宽时存在计算复杂度高的问题,尤其是在大斜视角度下,还存在距离方位耦合严重的问题。为此,本文在传统两步成像算法的基础上引入Chirp变标处理机制,结合距离走动校正技术,有效解决了斜视滑动聚束模式下距离方位耦合严重的问题,并显著提升了成像效率。实验结果表明,该方法在正侧视和斜视滑动聚束模式下均能实现良好的成像效果,且在大幅宽条件下表现出更高的计算效率。此外,通过对比斜视条件下不同幅宽的成像性能,验证了该方法在大幅宽条件下的适应性,为大斜视角度下的高分辨率宽幅成像提供了一种有效的解决方案。
张允聚
,
商明样
,
吕旖旎
,
仇晓兰
. 基于Chirp变标的星载斜视滑动聚束SAR自适应高效成像方法*[J]. 中国科学院大学学报, 0
: 2025019
-2025019
.
DOI: 10.7523/j.ucas.2025.022
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.
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