Abstract:

In the ultra-wideband synthetic aperture radar(UWB-SAR)imaging algorithms the back-projeetion algorithm(BPA)and the extended Omega-K algorithm(EOKA)have high imaging accuracy. But the complex interpolation operation in the imaging process brings about heavy computational load. The nonlinear chirp scaling algorithm(NCSA)does not need a complex interpolation process and has a higher imaging efficiency. Due to the approximation in the series expansion process, SAR images contain certain range and azimuth coupling sidelobe. This paper presents a new UWB-SAR imaging algorithm. The proposed algorithm does non-uniform FFT on the range-time domain data after range compression to cancel the range and azimuth coupling. The images delete the range and azimuth coupling sidelobe and have high quality. As the data number increases the proposed algorithm imaging efficiency is closer to NCSA imaging efficiency. Simulation results verify the correctness of the proposed algorithm.