New air traffic control surveillance technologies present great opportunities to obtain or derive large quantities of wind direction, wind speed and temperature observations in numbers unprecedented in the European region.

These observations in itself can be useful to aviation stakeholders and for the overall meteorological community. Furthermore, assimilating these additional observations in numerical weather prediction models enables rapidly updated short-range weather forecasts.

Modern aircraft carry sensors to measure the Mach number (using a pitot static probe) and air temperature (T). An enhanced surveillance (EHS) air traffic control (ATC) radar interrogates all aircraft in sight in a selective mode (Mode-S), on which the aircraft replies with a message containing, for example, magnetic heading, airspeed and Mach number. These messages can be collected by Air Traffic Control or by a network of local receivers. 

EMADDC has developed algorithms to derive calibrated and quality controlled meteorological observations. The process consists of quality control of Mode-S EHS data, conversion of magnetic to true heading, and aircraft specific corrections for heading and temperature. For the latter a dynamic database, updated daily, of individual aircraft heading and temperature corrections is used.