4r.5 Demonstration of Range Oversampling Techniques on the Wsr-88d

Among the planned upgrades for the NEXRAD network of weather surveillance radars are superresolution (1/4 km reflectivity and 0.5 deg radials) and polarimetric capabilities. In either case, keeping current update times (i.e., same antenna rotation rates) results in meteorological variable estimators with unacceptable large errors. A family of methods to reduce errors in estimates of spectral moments and polarimetric variables beyond those achievable with standard estimators has been proposed (Torres and Zrnić 2003a, 2003b, Torres et al. 2004) and is scheduled for inclusion in future upgrades of the WSR-88D Open Radar Data Acquisition (ORDA) subsystem. These techniques consist of oversampling echo signals in range, applying linear transformations to the samples, processing the sequences in time at fixed range locations to obtain covariance estimates, averaging these covariances in range, and finally combining them to compute the variables. This paper demonstrates the enhanced performance of estimators based on range oversampling techniques.