A Wavenumber-Domain imaging algorithm for Spaceborne/Airborne Hybrid Bistatic SAR

This paper focuses on the azimuth variant bistatic synthetic aperture radar (SAR) data processing in a spaceborne/airborne hybrid bistatic configuration. Due to the extreme differences in platform velocities and slant ranges, Spaceborne/Airborne Hybrid Bistatic SAR (SAH-BiSAR) data are more challenging to process than the translational invariant Bistatic counterparts because serious two-dimensional (2-D) spatial variations exist in SAH-BiSAR. To overcome this problem, a Wavenumber-Domain imaging algorithm (WDIA) for SAH-BiSAR based on linearization theory is proposed in this paper. Compared with the traditional WDIA for monostatic SAR and translational invariant bistatic SAR, the proposed algorithm uses a 2-D Stolt transformation to realize the 2-D frequency linearization. In this process, the 2-D spatial variations of the Doppler parameters and range cell migrations in SAH-BiSAR can be solved. Numerical simulations verify the effectiveness of the proposed method.