Near-field-to-far-field transformation using wavenumber migration technique for a 3D spotlight SAR

In this paper, we present the method to obtain the far-field radar cross section (RCS) for a 3D spotlight synthetic aperture radar raw data. The far-field RCS is closely related to the Fourier transform of the reflectivity. We estimate this Fourier transform data using wavenumber migration with some amplitude compensation. This estimated Fourier transform data eventually yields the far-field RCS. The simulation results for some point targets show that the far-field RCS using the presented method is similar to the analytical values.