The 17 operational German weather radars regularly point vertical for calibration. We proof that this data also contains valuable scientific information. To demonstrate this, we use it to detect the melting level in clouds and strong snowflake riming. Riming is the collision of a snowflake with liquid droplets, which can create precipitation. We analyze the frequency and temperature dependence of riming for all German weather radar sites and relate it to the local precipitation climatology.

A solid state transmitter was integrated into an existing C-band magnetron weather radar. This unique setup allows for an easy comparison of the data quality of both transmitters. Reflectivity, Doppler and Dual Pol moments are compared. The SSPA shows better data quality in areas with low signal strength. The gap between short and long pulse is treated well, range sidelobes around strong targets are an issue. SSPA is considered as a possible replacement for the ageing magnetron transmitters.

Wind turbine clutter (WTC) reduces the accuracy of weather radar measurements, as turbines may now be built closer to radar sites. A dynamic algorithm reliably detects WTC when wind turbine rotor speeds exceed 5 rpm. Beamblockage due to WT in the 5 km range is significant. A wind turbine-free 5 km radius is recommended.

The study examines the use of the spheroidal shape approximation for calculating cloud radar observables in rain and identifies some limitations. To address these, it introduces the empirical scattering model (ESM) based on high-quality Doppler spectra from a 94 GHz radar. The ESM offers improved accuracy and directly incorporates natural rain's microphysical effects. This new model can enhance retrieval and calibration methods, benefiting cloud radar polarimetry experts and scattering modelers.

Weather radars should use lightning protection to be safe from damage, but the rods can reduce the quality of the radar measurements. This study presents three new solutions for lightning protection for weather radars and evaluates their influence on data quality. The results are compared to the current system. All tested ones have very little effect on data, and a new lightning protection system with four rods is recommended for the German Meteorological Service.