System Design and Signal Processing in Spaceborne Squint Sliding Spotlight SAR with Sub-Aperture Block-Varying PRF

To tackle the problems of Doppler spectrum, aliasing caused by azimuth beam scanning and azimuthal serious non-uniform sampling in squint sliding spotlight synthetic aperture radar (SAR) with varying repetition frequency technology, method sub-aperture block-varying pulse (SBV-PRF) is proposed, where division judgement makes acquisition time each sub-block small enough so that bandwidth center change can be ignored. Based on echo signal characteristics a SBV-PRF transmission scheme, an pre-processing combining scheme proposed. Using this method, de-skewing first performed set data to eliminate additional introduced angle, then resampling ensure different have same rate. The technology reduces difficulty while ensuring complete mode. effectiveness system design processing verified point target simulation imaging results.