The patented TAMDAR sensor makes AirDat's superior weather forecasts possible. The sensor consists of an airfoil-shaped probe that extends through the aircraft skin into the airflow, and a small microprocessor-based signal processing unit inside the aircraft.

TAMDAR sensors are installed on commercial airliners, and transmit atmospheric observations continuously as the aircraft climbs, cruises and descends, providing a stream of atmospheric data via a low-latency global satellite network. TAMDAR observations are typically received, processed and available for distribution or assimilation into AirDat's models or other applications in less than 60 seconds from the time of the observation. The sensor requires no crew involvement; it operates automatically and sampling rates and calibration constants can be adjusted by remote command from AirDat's operations center.

With a continuous stream of observations, TAMDAR provides much higher resolution spatial and temporal distribution of observations than the weather balloon network, and a more complete data set than ACARS (MDCRS). It delivers thousands of daily observations from locations and at times not available from any other observing system. TAMDAR observations include not only temperature, pressure, and winds aloft measurements, but also humidity, icing, and turbulence. Each data point includes a GPS time/date/position/attitude stamp.

The accuracy of TAMDAR observations has been verified against weather balloons and aircraft test instrumentation. Documented case studies and statistical analyses show that the inclusion of TAMDAR data yields dramatic improvements in the accuracy of forecast models, particularly in dynamic atmospheric conditions.

AirDat's TAMDAR system has been in continuous operation on regional airliners since December 2004. AirDat has over 400 aircraft under contract for TAMDAR, providing coverage of the continental United States and Alaska. Agreements for an additional 500+ aircraft are under discussion.