Computational efficient high resolution algorithm for Sliding Spotlight SAR

Abstract:
High resolution sliding spotlight SAR poses the problems of high spectral bandwidth and high data volume, which impacts the needed processing power and system design. De-chirping has been proposed for reducing the spectral bandwidth and worked into the well-known algorithms. An additional preprocessing step is introduced in this paper, which globally reduces the range walk of the image targets to reduce the data and spectral coupling of azimuth and range direction. An efficient focusing algorithm is presented, which is able to handle the introduced “Global walk correction” step and de-chirping in azimuth. The algorithm only uses FFTs and phase multiplications to correct the total range walk and the Doppler phase for all targets simultaneously. Mathematical and performance analysis of the algorithm and numerical simulations are presented to validate the algorithm.