A comparison of tropospheric VHF Doppler beam steering and full correlation analysis measurements of aspect sensitivity

Abstract

Tropospheric VHF radar data collected using both spaced antenna (SA) and Doppler beam steering (DBS) methods are presented. The SA data are analyzed using full correlation analysis (FCA) on vertical beam data, while DBS analysis is applied to vertical beam data and off-zenith beam data at 3.6°, 7.2°, and 10.8°. A comparison of meridional velocities using SA FCA and DBS analysis is presented. These results indicate good agreement between the DBS and FCA velocities on all off-zenith beams, particularly at 10.8°. The main aim of the study is to compare the aspect sensitivity parameter θs ,using the spatial correlation method for the FCA data [e.g., Lesicar and Hocking, 1992] and the power method of Hocking et al. [1986] for the DBS data. This comparison reveals good general agreement between isotropic values of θs with both methods, and aspect sensitive values of θs values with both methods, although there are times when one method produces isotropic values and the other produces aspect sensitive values and visa versa. During aspect sensitive periods the FCA values agree best with the DBS method using the 0.0°–3.6° beam combination.