Effect of the spatial variability of precipitation on the differential propagation phase shift

The interaction between the electromagnetic waves emitted by a polarimetric radar and precipitation is in general complex because of propagation through a non-homogeneous medium. The incoming signal then receives contributions from both propagation and backscattering effects. In this work, we determine and characterize the effects of cross and down range variability of precipitation on the differential propagation phase shift.

We examine first the propagation of a plane wave through a non-homogeneous slab of dielectric spheres and obtain the equation for the far-field scattered wave. Secondly, we consider the propagation of a plane wave through a non-homogeneous dielectric slab and use the perturbation method to derive an analytical solution for the far-field scattered wave. Finally, we compare the two solutions, define an effective propagation constant and establish the variability of the refractive index on the precipitation rate. This in turn helps us to assess the effect of spatial variability of precipitation on the differential propagation phase shift.

We will show all the details and preliminary results.