A complete volume scan at 18 different elevation angles from 0.5 to
37° is conducted every 15 min (Bartels, 2005). The scan consists of two
different measuring modes: The intensity mode with a range of 230 km,
covering the lowest 4.5°, and the Doppler mode with a range of 120 km,
covering the elevation angles above. The precipitation scan, which is
used to estimate surface rain intensity via a Z–R-relation (Sauvageot,
1992), is carried out between the volume scans every 5 min between
0.5 and 1.8°, depending on the orography. Unfortunately, raw data
from the volume scans are stored only since 2010. For this reason, we
had to use specific DWD radar products with a limited accuracy