The German Weather Service (DWD) maintains ground based network of different instruments. One of these is the operational C-band Radar network. SAMD provides the data of the high level product RADOLAN, reflectivity and precipitation data on a regular grid, with 1x1km² horizontal and 5 minutes temporal resolution. Furthermore DWD provides cloud bottom heights from the ceilometer. Find more at: DWD.
The GFZ German Research Centre for Geosciences in Potsdam operates a German wide ground-based GNSS atmosphere sounding network. GNSS stands for Global Navigation Satellite Systems. One of the products is the path of integrated water vapor, provided in SAMD. For further information please have a look at: GFZ.