Precise estimation of propagation parameters in
precipitation media is of interest to improve the performance
of communications systems and in remote sensing applications.
In this paper, we present maximum-likelihood estimators of
specific attenuation and specific differential phase in rain. The
model used for obtaining the cited estimators assumes coherent
propagation, reflection symmetry of the medium, and Gaussian
statistics of the scattering matrix measurements. No assumptions
about the microphysical properties of the medium are needed.
The performance of the estimators is evaluated through simulated
data. Results show negligible estimators bias and variances close
to Cramer–Rao bounds
