The polarimetric properties of the radio channel, with particular reference to the Dense Multipath Components (DMC), are analyzed in the present work for different types of outdoor and indoor environments, with the aid of measurements and Ray Tracing (RT) simulations. A heuristic Diffuse Scattering model, suitable to be embedded in RT tools, is properly tuned and parameterized to reproduce the cross-polar discrimination (XPD) characteristics of the DMC extracted from measurement data in the above mentioned scenarios.