The detectability of tornadic signatures with Doppler radar: A radar emulator study

A radar emulator has been developed to simulate the returns from a scanning radar on a pulse to pulse basis. This emulator uses high resolution numerical simulations as input, and samples the numerical grid based on the user's configuration, producing simulated radar reflectivity, Doppler velocity, and Doppler spectrum width. The emulator is capable of simulating azimuthal over- and under-sampling, gate spacing, velocity aliasing, range aliasing, antenna beamwidth and sidelobes, and frequency-dependant attenuation.

The ability of Doppler radars to detect a tornadic signature has been tested using this emulator. The input consisted of a numerical simulation of a tornadic supercell. Detectability was examined as a function of range from the storm, elevation angle, azimuthal sampling interval, beamwidth, and pulse repetition frequency. Simulated radar returns from a non-tornadic time were also examined to determine whether the radar could distinguish between non-tornadic and tornadic circulations.