Image formation from spaceborne synthetic aperture radar signals

The digital signal processing problem posed by the transformation of satellite SAR phase history data into images has been addressed by the development of a processor that depends on a high speed computer and complex algorithms for efficient operation. These algorithms perform a two-dimensional convolution of the radar returns with a nonstationary matched filter. The image quality obtained depends on the accuracy maintained in reconstructing the complete radar signal phase history, and in compensating for such effects as beam squint, earth rotation, and range cell migration. Examples are given which demonstrate processor achievement of theoretical resolution limits.