Wednesday

I will describe a joint project involving the University of Exeter and the Met Office that aims to acquire real-time, low-cost, high-volume measurements of atmospheric humidity to inform numerical weather forecasts. Commercial air traffic broadcast radio signals that encode their GPS-determined position, speed, and heading, along with data physical data such as in situ pressure and temperature. Angle-of-arrival interferometry of these signals can also yield a measure of humidity, as the deviation of observed elevation angle from predicted elevation angle is due to refraction, which in turn is affected by humidity (at the level of a few tens of percent of the normal stratification-induced refraction). I will describe a prototype system deployed currently at the University of Exeter, and look forward to a planned network of interferometers deployed on the Met Office radar towers across the UK.