Blind polarimetric equalization of UWB SAR imagery

Polarimetric synthetic aperture radar (SAR) imagery is susceptible to degradation due to non-ideal responses in antennas and other hardware. While a number of polarimetric calibration procedures have been developed to compensate for these effects, most are limited to narrowband SAR systems. The few that are applicable to ultrawideband (UWB) SAR suffer from a dependence on high-quality antenna measurements or detailed electromagnetic scattering models of test targets. Here a blind polarimetric equalization (BPE) technique is developed that uses second-order statistics from clutter or targets of opportunity to estimate the SAR system response. These estimates are then used to remove crosstalk contamination and imbalances between polarimetric images. The novel frequency domain implementation makes BPE suitable for ultrawideband SAR systems. BPE is an image post-processing procedure that does not require changes to radar hardware, antenna measurements, or target predictions