Effects of Phased-Array Broadside Beamwidth Shapes on Velocity Signatures of Modeled Vortices: Simulation Study

A planar face phased-array radar (PAR) emulator was used to investigate the effects of beam broadening on Doppler velocity signatures of various-sized modeled vortices at various ranges from the PAR. The ellipsoidal beam shape varied as a function of azimuthal as well as elevation directions for a broadside circular beam. A basic characteristic of the PAR antenna is that the beamwidth increases as the radar beam electronically scans away from the horizontal as well as vertical broadside direction perpendicular to the face. Simulated PAR velocity data were recorded on constant elevation surfaces at grid points with constant radial spacing and varying azimuthal and elevation spacings. At a given grid point, a mean Doppler velocity value was computed as an integrand in a triple integral within the ellipsoidal beamwidth.

To investigate the influence of beamwidth on vortex detection, we scanned a virtual radar having a phased-array and WSR-88D antennas through the center of various-sized analytical vortices representing tornadoes and mesocyclones. Simulated PAR velocity data were then compared to those produced by a simulated WSR-88D. At the Symposium, we will assess detection and estimates of simulated Doppler velocity signatures produced by two different radars.