Evidence of tilted layers in angle of arrival and Doppler beam steering power measurements

The results of an experiment combining Doppler beam steering (DBS) and angle of arrival (AOA) measurements are presented. Nonzero vertical beam AOAs and off zenith DBS power measurements have been attributed by various authors to the tilting of horizontal layers in the atmosphere. This study aims to directly compare vertical beam AOAs and off zenith beam power data to determine whether the relationship between the two sets of measurements is consistent with tilted layers. The results indicate that the power differences in beams at 3.6° off zenith are related to the vertical beam AOAs and that the variation of the two quantities is consistent with tilted layers being observed in all of these beams. In contrast, the power differences at 10.8° off zenith do not appear to have the same relationship to the vertical beam AOAs.