Wavefront Curvature Compensation Polar Format Algorithm Based on Digital Spotlighting Preprocessing.

In this paper, a new wavefront curvature compensation method based on digital spotlighting preprocessing is proposed. First, digital spotlighting preprocessing, filtering and downsampling in 2-dimensional space domain, is performed on echo data. This generates multiple full-resolution phase histories of smaller image patches, each corresponding to a narrow-beam phase history data where the wavefront curvature effect can be ignored. Due to the inherent non-planar motion compensation capability, PFA is used to produce focused fine resolution image for each small patch. Finally, all focused image patches are seamed together to get a full image. Simulation experiments show that the new algorithm has improved focused scene size when applying to phase history generated by non-ideal radar flight path. [ABSTRACT FROM AUTHOR]