Detection and imaging of arbitrarily moving targets with single-channel SAR

In synthetic aperture radar (SAR) images, moving targets cause imaging errors such as defocusing and/or displacement, depending on the direction of their motion. To obtain a correct and focused image of the moving targets, knowledge of the target parameters, position and velocity, is necessary. An algorithm for detection, parameter estimation, and imaging of ground-based targets, moving in arbitrary directions, is presented. The algorithm is based on evaluation of a sequence of single-look SAR images which is generated from conventional, single-channel SAR raw data. The position and velocity of the moving targets are estimated by applying two observation models, whereby aliasing due to a motion induced Doppler shift is considered. In this way, the moving targets can be detected almost independently of their moving direction. The estimated parameters are used to compensate for the imaging errors in the SAR images. Finally, the real motion of the targets in the scene is visualised in a compensated image sequence.