In order to acquire the data for the development of climatological models and forecasts, meteorology needs to access RF spectrum. In France, Météo France is the entity using radio frequencies for these purposes.
A number of satellite sensors currently collect meteorological and climatological data, for which sustainable spectrum availability must be provided. This applies to frequency ranges suited to the observation of natural phenomena as well as to frequency bands carrying the collected data back to Earth. For space applications, current usage and developments depend on projects led by EUMETSAT for Europe and by other meteorological satellite operators at global level (e.g. NOAA in the United States or CMA in China). Projects managed by other space agencies present on the international scene (CNES, ESA, NASA, JAXA) are also vital for subjects more specifically related to Earth observation.
Apart from satellite systems, acquisition of meteorological data uses three other types of RF devices:
- drifting balloon-borne radiosondes collecting data using frequencies in the 403 MHz range to transmit the data back to ground;
- 2.8 GHz, 5.6 GHz and 9.4 GHz meteorological radars, used to detect the movement of weather disturbances; in future, higher frequency bands — 24 GHz, 35 GHz, 95 GHz — will enable radars to be deployed for measurements related to hydrometeors or clouds;
- 45 MHz and 1280 MHz wind profiler radars. Among the developments in radio applications servicing meteorology are land-based passive radiometers for the measurement of certain characteristics connected to the gaseous composition of Earth’s atmosphere (for example in the 20/30 GHz, 50/60 GHz, 90 GHz, 150 GHz and 183 GHz frequency ranges).