Fourier-based ISAR imaging using 2D polynomials

Inverse synthetic aperture radar (ISAR) image formation is a problem that has been studied for many decades. Despite the effort made by many researchers and practitioners, it is still an open problem as it involves non-trivial aspects both in terms of geometry and scattering mechanisms. In this study, the authors introduce a new interpretation of classical ISAR signal modelling, based on two-dimensional polynomials, providing an alternative perspective that permits the in-depth investigation of the problem of ISAR image formation when using a Fourier transform-based approach. The interpretation of target motion compensation and image autofocus are connected through a mathematical formulation that explains in depth what can and should be compensated in the received signal prior to applying the Fourier transform and therefore forming the ISAR image.