Outer circular synthetic apeture radar imaging based on Maxwell's equations

A general synthetic aperture radar (SAR) signal model based on the Maxwell's equations is derived, and three approximations are discussed for engineering applications. Based on this signal model, a novel operation of SAR, called outer circular synthetic aperture radar (Outer-CSAR), is investigated for wide observation. The Outer-CSAR works similarly to the general circular SAR, but the beam of the SAR antenna points at the outer of the circle instead of the inner. The signal model and imaging algorithm are presented for the Outer-CSAR, and furthermore, simulation is given to validate the signal model and imaging algorithm.