Comparison of horizontal winds and turbulent eddy dissipation rates obtained by two different multi-receiver techniques - Spaced Antenna and Postset Beam Steering

The horizontal winds and eddy dissipation rates (ε) obtained by two multi-receiver techniques, Spaced Antenna (SA) and Postset Beam Steering (PBS), are compared and contrasted, using Middle and Upper atmospheric radar measurements. Comparison of mean horizontal winds obtained by both methods indicates a good agreement in zonal and meridional winds. On the other hand, the agreement in ε derived by SA and PBS is good in the lower troposphere (below ~9 km), but the profiles of ε show some discrepancy in the upper troposphere. While the discrepancy is relatively more in layers of depleted turbulence, it is small in layers of enhanced turbulence. Comparison of signal-to-noise ratio and turbulence variations reveal that these variations are not due to specular echoes, rather due to anisotropic turbulence. The study suggests that these techniques and correction formulae for spectral width work well in the regions of enhanced turbulence but yield relatively less accurate values in regions of depleted turbulence.