Upstream Wind Sensing for Small Unmanned Aerial Vehicles

The potential for measuring wind, both in the atmosphere and in wind tunnels, was investigated using differential pressure probes mounted forward of small fixed wing and rotary unmanned aircraft. Stability augmentation on the fixed wing craft demonstrated improved steadiness when the upstream pitch angles from the turbulent wind were used as a control input in association with a standard inertial unit. Velocity spectra in the atmosphere and those from flights in turbulent wind tunnels were similar to the generally accepted von Karman spectra. The problems and possibilities of using small unmanned aircraft for outdoor measurements are discussed including in swarms which could replace anemometers mounted on masts.