Target motion compensation by spectrum shifting in synthetic aperture radar

Target motion can severely distort the image in a conventional synthetic aperture radar (SAR) by causing targets having even small components of radial velocity to be lost or to appear with enormous along-track errors. The presence of moving targets in the image can be detected from the spectral characteristics of the data samples contained in the synthetic aperture sequences being processed. By isolating the spectra of the moving targets and translating them to a point near the origin before carrying out conventional SAR processing, the moving targets can be made to appear as their correct locations in the final image. The theoretical basis for the correction procedure is developed and simulation results for a typical system are presented