Aircraft Meteorological Data Relay
The Aircraft Meteorological Data Relay (AMDAR) is a project for the acquisition of meteorological data that has been used in operational operations by the World Meteorological Organization (WMO) since 1991.
In the AMDAR project, the on-board temperature, pressure and, in some cases, humidity sensors of modern, commercially used airliners are used to obtain information about the vertical distribution of temperature and humidity in the atmosphere . In Germany, Lufthansa aircraft in particular are equipped with the appropriate technology. The data collected in this way are preprocessed in the aircraft and then transmitted directly to a receiving station on the ground via VHF communication via ACARS (Aircraft Communications Addressing and Reporting System) or via satellite link via ASDAR (Aircraft to Satellite Data Relay). Once the data has been received, it is collected centrally and undergoes intensive quality control and post-processing before it is distributed to the airlines , weather services and other users.
With the help of these additional vertical soundings to the existing radiosondes , a significantly better temporal and spatial resolution of vertical soundings of the atmosphere is available, particularly in areas with increased air traffic. In addition to this, there are also soundings in areas where no radiosonde ascents take place, but a commercial airport is nearby. An example of this is Hamburg , because although there is a commercial airport here with around 16 AMDAR vertical soundings per day, the nearest radiosonde stations of the German Weather Service are around 120 kilometers north in Schleswig and around 80 kilometers south in Bergen .