Doppler Velocity Recovery and Dealiasing Algorithm for Multi-PRT Scans in Weather Radars

Pulsed Doppler radars are susceptible to range-velocity ambiguities inherent from using a uniform train of electromagnetic pulses to sample the atmosphere. Ambiguities arise due to the well-known Doppler dilemma, where increasing the pulse repetition time (PRT) increases the maximum unambiguous range but decreases the maximum unambiguous velocity and vice versa. Demands on any of the techniques to simultaneously mitigate these range-and-velocity ambiguities increase to a point of breakdown when they are needed most, that is, in the presence of widespread outbreaks of severe weather with convective storm over large areas. In this article, we present an algorithm to increase the region of valid Doppler velocities recovered when multi-PRT scans are used. The velocity recovery and dealiasing (VRAD) algorithm blends data from different scans and uses simple dealiasing techniques to mitigate regions with obscured velocity estimates. Data from the operational WSR-88D network are used to demonstrate the algorithm. On average, the algorithm is able to increase valid velocity estimates by 25.67% in conventional scans (i.e., nonphase coded) and 12.42% in phase-coded scans.