Contrast Optimized PGA Algorithm for P-band UWB SAR

The phase gradient autofocus (PGA) technique has been proved to be a superior method for higher order autofocus. However, given the different nature of P-band ultra-wideband synthetic aperture radar (UWB SAR) imagery and very low signal-to-clutter ratio in the data, conventional PGA algorithm usually fail to yield robust focusing result on raw data without distortion. We proposed the modified PGA algorithm that combines the traditional PGA with contrast optimization principle and reference scatterer coregistration. Our method is successfully applied on raw P-band UWB SAR image and excellent results are attained