SZ-2 Algorithm Updates for the NEXRAD Network

Range (out-of-trip echoes) and velocity (aliasing) ambiguities arise in Doppler weather radars due to the large spatial extent and intense velocities associated with some weather conditions. For years, the SZ-2 algorithm has been used in the WSR-88D radar network to mitigate these ambiguities. The current SZ-2 algorithm uses a dwell of uniformly, non-phase-coded, long-PRT samples to recover estimates of reflectivity and polarimetric estimates and a dwell of uniformly, phase-coded, short-PRT samples to recover Doppler velocity and spectrum width estimates. Future improvements to the SZ-2 algorithm will integrate new ground clutter mitigation techniques (i.e.: Clutter Environment Analysis using Adaptive Processing, CLEAN-AP, and Weather Environmental Thresholding, WET) and extract high-quality polarimetric estimates from the phase-coded short-PRT samples. In this work, we present the performance of the proposed SZ-2 algorithm upgrades using simulations and archived WSR-88D data. These results confirm the suitability of these techniques for future SZ-2 upgrades of the WSR-88D radar network.