Using omega‐ K algorithm for bistatic synthetic aperture radar image formation based on modified extended Loffeld's bistatic formula

Bistatic synthetic aperture radar (BSAR) as a way of Earth remote sensing has been developed considerably in recent years, both theoretically and practically due to its unsubstitutable services. BSAR frequency‐domain processing algorithms are efficient ways of image formation in comparison to ideal two‐dimensional matched filtering and to relatively accurate and time‐consuming time‐domain algorithms. Among these frequency‐domain algorithms, omega‐ K is the most precise. The starting and key step of frequency‐domain algorithms is the derivation of bistatic spectrum. Recently, a new bistatic spectrum is reported, which is probably the latest and the most modified version of Loffeld's bistaic formula (LBF), maintaining its accuracy even in azimuth‐variant configurations with high squint angles. So far, this spectrum has only been used within range‐Doppler algorithm to process BSAR data. The authors investigate the possibility and results of applying this modified version of LBF as a basis for omega‐ K algorithm. Two approaches, based on Stolt interpolation and inverse scaled Fourier transform, are examined and their effectiveness in general azimuth‐variant geometry is validated through several simulations. The proposed implementations show higher performance in terms of image quality measurements as compared to extended LBF‐based implementations.