Distortion in ISAR Imaging and Restoration of Distorted ISAR Images

摘要

A physics based numerical model has been developed to describe the gross distortion on ISAR images due to small perturbed target motion. Quantitative results obtained under controlled experimental conditions on the target's motion have confirmed that large distortion in the ISAR image of the target can occur. The experimental data give excellent agreement with the model results. The distortion is a consequence of the phase modulation effect in the radar return signal, as a result of small fluctuating perturbed motion of the target. This gives rise to distortion of the image in the cross-range direction. The distortion can be corrected by applying time-frequency analysis. The Short- Time Fourier transform is used in this paper to examine some of the issues in refocusing distorted ISAR images.