Urban Impacts on UAS Dynamics-based Wind Observations

With the increase in the use of uncrewed aircraft systems (UAS) for real-time weather forecasting, there is a need to better understand the impact of urban terrain to improve the safety of low altitude aircraft operations within urban areas. This requires integration of measurements with autonomous systems since current available sampling lack sufficient resolution within the atmospheric boundary layer (ABL) in general and within the urban boundary layer (UBL) specifically. In particular, the urban roughness sub-layer is an important region requiring better observations to understand atmospheric turbulence depth and their impact on coupling of the surface to the UBL. Of emerging importance is the ability to observe coupled anthropogenic effects to quantify undesirable positive feedbacks within urban regions. Targeted observations include humidity within the UBL and variations in suburban and high-rise urban canopies. The current work combines laboratory and fielding testing to assess the ability to measure variations in wind speeds within the UBL with UAS along with ground stations for kinematic and thermodynamic, as well as flux measurements. When combined with measurements of boundary layer depth and structure, flux measurements provide the potential for comprehensive assessment of the impact of the surface energy balance on UBL dynamics. Field testing shows that the mean and fluctuating wind speed statistics obtained from a UAS-based sensors were within measurement uncertainty of a similar measurement simultaneous acquired from ground sensors in rural and urban locations in preparation for urban field campaigns in 2023 and 2024.