Spatially sampled measurements of atmospheric turbulence using unmanned aerial vehicles

This paper provides an overview of recently conducted experiments in which atmospheric boundary layer turbulence was measured by unmanned aerial vehicles. These experiments were conducted as part of the large-scale “Lower Atmospheric Process Studies at Elevation - a Remotely-piloted Aircraft Team Experiment (LAPSE-RATE)” measurement campaign held in Colorado’s San Luis Valley. Two types of measurements are examined, the first type is focused on measuring profiles of thermodynamic properties for atmospheric boundary layer investigations. Profiles of temperature, wind velocity, and turbulent kinetic energy measured during a morning transition from stable to convective conditions were examined for altitudes up to 900 m above ground level. The second measurement type utilizes long transect flights over nearly homogeneous terrain to spatially measure turbulence statistics. Energy spectra and velocity structure functions up to 10th order were examined and the scaling of the structure function exponents compared to those measured from prior studies.