Portable Aircraft-Derived Weather Observation System

A low-cost technology can increase the number and quality of wind and temperature atmospheric observations made by aircraft to improve forecasts.
A weather sensor is setup on a tripod in a field.
The PADWOS instrument, like the one pictured, is installed at various National Weather Service, airport, and university host sites. The instrument collects atmospheric data recorded by aircraft transponders within 60 nautical miles. Photo: Glen Cooper

Atmospheric observations collected from aircraft, such as temperature and wind, provide the highest-value inputs to weather forecasting models. However, these data collections are sparse and delayed, currently obtained through specialized systems installed on select aircraft.

The Portable Aircraft-Derived Weather Observation System (PADWOS) provides a novel, low-cost, standalone technology for significantly increasing the number and quality of wind and temperature atmospheric observations that can be made by existing and future aircraft.

The technology leverages Mode S Enhanced Surveillance (EHS) transponders, which are already installed on more than 95% of commercial aircraft and the majority of general aviation aircraft. From the ground, PADWOS interrogates Mode S EHS–equipped aircraft, collecting in milliseconds aircraft state data reported by the transponder to make wind and temperature estimates. The system holds promise for improving forecasts, monitoring climate, and supporting other weather applications.