An improved wavenumber domain algorithm for circular SAR and cylindrical reconstruction areas

In this paper, an improved wavenumber domain imaging algorithm is proposed for circular synthetic aperture (CSAR) data taken in stripmap mode. The proposed algorithm allows to reconstruct an image on a cylindrical surface. The range trajectory is approximated with the fourth-order terms expansion and the echo signal is transformed to the wavenumber domain by using a principle of stationary phase. Based on the spectrum, the interpolation of the algorithm is deduced, and the residual phase is compensated. The valid aperture length of the proposed algorithm is greatly increased, comparing with the algorithm based on range expanded to quadratic terms. The simulation results validate the high-performance of the improved wavenumber domain imaging algorithm.