SAR image formation via inversion of Radon transforms

This paper reviews how image formation or reconstruction in synthetic aperture radar (SAR) in two and three dimensions can be viewed as the inversion of the circular and spherical Radon transforms, respectively. The advantage of viewing image formation in this way is that it could be used in situations where more standard methods could fail, such as high squint and ultra-wideband SAR. The inversion formulae for the circular and spherical Radon transforms employ Hankel and Fourier transforms along with coordinate mappings. We show how the theory extends to include finite bandwidth signals and finite synthetic apertures.