Efficient stripmap SAR processing for the implementation of autofocus and missing pulse restoration

摘要

A moving radar generates a search mode synthetic aperture image of a patch from a sequence of periodic pulse returns having one or more missing pulses. An azimuth and range interpolation generates an interpolated sequence having samples oriented in range and azimuth frequency with uniform spacing. Range compression is performed using an IFFT. Azimuth deskew, an autofocus and pulse restore generates a focused and restored sequence. Azimuth reskew, and gain phase equalization generates an equalized sequence. A first linear phase is summed to the equalized sequence for applying a fractional sample shift in range frequency. A range FFT and Along Track IFFT is further applied to obtain a domain changed sequence. A second linear phase is summed to the domain changed sequence. A CT FFT of the result generates an image of the patch. The azimuth interpolation and range interpolation also include a Stolt interpolation after a matched filter function.