The observations from meteorological stations (DWD, Meteorological and Geographical Institutes, research organizations, etc.) provide continuous information on the atmospheric state. In particular we will use data from  DWD observatories (Hohenpeissenberg, Lindenberg); especially at Lindenberg a wealth of remote sensing (radiation, microwave radiometer, ceilometer, Raman lidar, cloud radar, wind profiler, GPS etc.) and in situ instrumentation is available as well as 4 radiosoundings per day. The observations will allow the characterization of the atmospheric state (in particular the boundary layer and clouds) as complete as possible.

• Further observatories of diverse operators can provide information from interesting locations (UFS Schneefernerhaus; Schwarzwald Observatories Hartheim and Tuttlingen).

• Observatories of foreign weather services including for example the Cloudnet sites Cabauw, Chilbolton and Palaiseau which provide information on the vertical cloud distribution.

• Meteorological and also geographical institutes operate a rather complete set of instrumentation; as an example the available instruments at the Meteorological Institute Bonn consists of lidar ceilometer, microwave radiometer MICCY, infrared radiometer, micro rain Radar, X-Band Radar, Scintillometer, rain gauges, weather station. This also includes foreign institutes like the IAP Bern.