Microwave Doppler-polarimetric technique for study of turbulence in precipitation

Describes some results of a joint research project of the International Research Centre for Telecommunications-transmission and Radar (IRCTR) at the Delft University of Technology (The Netherlands) and the Kiev International University of Civil Aviation (Ukraine). A complex of mathematical models is developed to describe features of manifestations of rain microstructure and turbulence in rain during their interaction with the radar signal. Computer simulation of Doppler-polarimetric spectra of the radar signal from rain is done on the basis of these models. The general model uses rain microstructure and turbulence parameters as initial data. The model gives Doppler spectra at different combinations of linear polarization of transmitting and receiving waves. Specific differential reflectivity Zdr(v) and linear depolarization ratio Ldr(v) are calculated as functions of Doppler velocity v. The model establishes the relationships between microstructure of and turbulence in rain and Doppler-polarization parameters of the radar signal. Verification of the model is done using Delft Atmospheric Research Radar DARR, which is able to measure Zdr(v) and Ldr(v) as radar observables. The results obtained show qualitative and quantitative relationships between measured Doppler polarimetric parameters and turbulence intensity using both physical and statistical considerations