Azimuth Spatially-Varying Phase Compensation for ISAR Based on Non-Uniform Fast Fourier Transform

Traditional Inverse Synthetic Aperture Radar (ISAR) imaging algorithms overlook the impact of higher-order rotational phase of target echoes, resulting in poor azimuth focusing and challenges in imaging maneuvering targets. To address this issue, this paper proposes a method for compensating azimuth spatially-varying phase errors based on Non-Uniform Fast Fourier Transform (NUFFT). This method establishes a model for the spatially-varying phase errors of maneuvering targets and utilizes the NUFFT technique to accelerate the rapid compensation of azimuth spatially-varying errors (AVSE) in two-dimensional ISAR images, effectively reducing computational complexity and achieving fast focusing of the images. Experimental results demonstrate that this method is effective and robust for ISAR imaging of maneuvering targets.