Determination of propagation parameters from fully polarimetric radar data

The polarization characteristics of the electromagnetics waves, as related to its interaction with targets, is an important aspect in remote sensing applications. This polarization information is usually contained in either the scattering matrix or the covariance matrix depending on the target under consideration. Often, propagation effects are normally not considered in obtaining them. In clear-air conditions this a reasonable assumption, but when rain, or any other type of precipitation, exists in the ray-path, depolarization of the waves may not be negligible anymore. The anisotropy that precipitation media present causes this depolarization and that could greatly affect the scattering or covariance matrix measurements. Consequently, the real target information may be hidden in those measured matrices and it could be necessary to apply different algorithms to correct for depolarization effects prior to target information extraction. Depolarization effects can be determined and accounted for if the characteristic polarizations of the medium and their respective propagation constants are known. It is found that for precipitation media that generally present reflection symmetry these polarizations are linear and orthogonal. Then it is shown that differential attenuation can be obtained from copolar power measurements and differential phase shift from copolar correlation measurements. Considering the statistics of these covariance matrix elements and temporal correlation between successive pulses from the target, statistics of propagation parameters are analyzed