Bistatic ground-based SAR fast imaging algorithm based on subblock division

Bistatic ground-based synthetic aperture radar (GBSAR) can acquire images of targets from different directions, which exhibits distinct imaging characteristics compared to monostatic system and has potentially important applications in multidimensional mountain deformation measurement. However, bistatic GBSAR imaging algorithm still faces problems including complicated bistatic Doppler history, high computational cost and unsuitability for near scenes. In this paper, a novel imaging algorithm for processing bistatic GBSAR data is proposed. After the range cell migration correction based on Keystone transform, the focusing is realized by subblock focusing in range-Doppler domain. The algorithm can adapt to complicated Doppler history of bistatic GBSAR and focus targets in near scenes with relatively high computing efficiency, which is suitable for mountain deformation monitoring. Finally, the validity and reliability of the algorithm are verified by simulated data and measured data.