A modified vad technique for analysing wind fields with doppler radar

Abstract The Velocity Azimuth Display (VAD) technique is often used to estimate the windfield with a Doppler radar. Different techniques have been used to identify a sinusoidal signature in the data, such as the Fourier transformation, and least square fitting of a sinusoid over data. Difficulties in these techniques occur when the data is noisy and when there is a restricted azimuth range in which there is data. A modified VAD method is presented which uses a different technique to get information about the windfield and can succeed in some cases where standard methods fail. Instead of a full sinusoidal fit, partial fits are done to get characteristics about the wind field. The method also has applications when the windfield is not homogeneous. Comparisons with other techniques are presented. Quality control is done by comparison of results from data from two radar with overlapping coverage.