An Autofocus Imaging Method of One-Stationary Bistatic Synthetic Aperture Radar

Since the trajectory deviations of the platform cause serious phase errors that degrade the focusing quality of synthetic aperture radar (SAR) imagery, an autofocus method is important for airborne SAR imaging. When it comes to one-stationary bistatic SAR (OS-BiSAR), autofocus problems become more complicated. Traditional autofocus methods make the assumption that a Fourier transforms relationship exists between the image domain and the range-compressed phase history domain, which is invalid in OS-BiSAR imaging. Based on maximum image sharpness criterion, an autofocus backprojection method is proposed. Its performance has been demonstrated by using the P-band airborne BiSAR experimental data.