Perturbation Decay Constant Effects of Power-Law Errors on Refraction Autofocus

Recent investigations have yielded techniques for estimating and compensating for the deleterious atmospheric refraction effects in synthetic aperture radar (SAR) image data. The defocused imagery are due to the bending and delay of the each radar pulse as it is refracted by the intervening atmosphere. One advantage of these recent methods is that they are robust to the bending and delay effects that can be different for each individual radar pulse along the synthetic aperture, since local atmospheric parameters can vary along the trajectory of the radar. Robust analysis of the performance of this refraction-based autofocus can be performed by using radar pulse bending and delay that are modeled as power-law spectra. The present analysis considers the effects of varying the value of the decay constants of the power-law spectra upon the overall focus quality of the imagery. These refraction autofocus techniques give well-focused imagery when applied to measured K-band data wherein power-law bending and delay errors have be inserted into the radar data.