Azimuth and Range Optimization of the Velocity Azimuth Display (VAD) algorithm in the WSR-88D

The Velocity Azimuth Display (VAD) algorithm occasionally produces inaccurate wind estimates for the VAD Wind Profile (VWP) product of the Weather Surveillance Radar 1988 Doppler (WSR-88D) System. Weather forecasters have observed differences between the radar's wind profiles and wind profiles produced by rawinsondes and vertical wind profilers, when radiation and subsidence inversions in the atmosphere caused the radar beam to super refract. This thesis sought to improve the operational use of the VWP product for the WSR-88D near Denver, CO, by finding the optimal VAD algorithm Azimuth and Range parameter settings to overcome data contamination by hills located at the default range used by the algorithm. The WSR-88D Algorithm Testing and Display System (WATADS) processed 24 weeks of archived (level II) VAD wind data, which was verified by rawinsonde and vertical wind profiler data. Azimuth optimization was unsuccessful. However, reducing the range not only provided an average improvement in the accuracy of winds obtained under super refractive conditions, but also in the accuracy of those winds obtained when the atmosphere was not super refractive. In the overall average, the range which produced the most improvement over default range (30 km) accuracy was 28 km. The 26 km range also performed well.Air Force Inst of Tech Wright-Patterson AFB OH is the author of 'Azimuth and Range Optimization of the Velocity Azimuth Display (VAD) algorithm in the WSR-88D', published 1998 under ISBN 9781423562801 and ISBN 1423562801.