Improving the Quality of Dual Polarization Estimates Using Adaptive Pseudowhitening

Range oversampling processing techniques can be utilized to reduce the variance of estimates and/or reduce observation times. Adaptive pseudowhitening is a range oversampling processing technique that was implemented on the National Weather Radar Testbed phased array radar to reduce observation times. With the advent of the dual polarization upgrade of the NEXRAD (Next Generation Radar) network, it is natural to look at ways to apply range oversampling processing to dual polarization estimates. Obtaining accurate dual polarization estimates is a challenge with the current scanning strategies and processing on the WSR-88D (Weather Surveillance Radar – 1988 Doppler), but adaptive pseudowhitening can improve the standard deviation of estimates by over a fact of two in certain situations. To quantify the performance of this technique over a broad range of conditions, simulations were carried out and analyzed. Oversampled dual polarization data was also processed with the new dual polarization adaptive pseudowhitening algorithm to look at the performance qualitatively.