Aspect sensitivity of VHF scatterers in the troposphere and stratosphere from comparisons of powers in off-vertical beams

The aspect sensitivity of the radar backscatter power at 46.5 MHz has been examined for the troposphere and lower stratosphere. Use is made of the width of the effective backscatter polar diagram, assumed to be Gaussian, derived from the ratios of signal strength for different pairs of beam directions in order to distinguish between anisotropic and isotropic scattering. The results are used to examine the relative contributions of isotropic scatter, anisotropic scatter, and Fresnel reflection or scatter to the signal backscattered in the vertical direction. Furthermore, the change in the scattering characteristics during the passage of a warm front is examined.