The Polarimetric Doppler Weather Radar POLDIRAD is operated for research since 1986 jointly with the DLR Institute of High Frequency Technology. The main characteristics of the C-band system comprise the polarisation agility for transmitting, the dual-channel receiving, the Doppler capability and the real time processing and display. A selection of two parameters out of the following are available for real time display: reflectivity factor for each polarisation of choice; the differential reflectivity; and the depolarisation ratio for a selected polarisation, especially the linear depolarisation ratio; or the circular depolarisation ratio; the Doppler velocities; and the Doppler spectral widths for both receiving channels. Time series products as the differential propagation phase will be available in real time soon.
The radar has been used to estimate the dynamical and the connected microphysical cloud structures and their developments with their lifetimes. We can distinguish snow, graupel, hail and rain. Numerous deep convective cloud systems as different types of thunderstorms, frontal systems and squall lines have been investigated, described and documented in great detail.
The quantitative estimation of precipitation, lightning as depending on the microphysical developments and NOx production in thunderstorms are topics of actual interest.
By the results gained with POLDIRAD and the experience with this system, we contribute to the European Action COST 75 on Advanced Weather Radar Systems.