Processing of Mosaic SAR Using Time Frequency Analysis and Azimuth NCS Algorithm

Mosaic synthetic aperture radar (SAR) can achieve high resolution and wide swath (HRWS) imaging by steering its antenna beam elaborately. However, its unique time-frequency diagram and radiometric variation challenge the imaging. The conventional methods cannot be applied to mosaic SAR imaging directly. To address these problems, this article takes the imaging geometry into consideration, utilizing time frequency transform to suppress the spectrum ambiguity. Then, the azimuth nonlinear chirp scaling (NCS) algorithm is performed to compensate the variant modulation and the pattern weighting approach is used to correct the radiometric variance. Simulation results verify the effectiveness of the spectrum analysis and the proposed imaging algorithm.