High-Resolution In Situ Measurements of Three-Dimensional Kinematic Properties of an Urban Boundary Layer Using an Instrumented Unmanned Aerial System

Atmospheric flow in an urban environment is complex and characterized by shear, acceleration and deceleration of flow, separation, and turbulence. Most investigations of flow in the urban boundary layer to date have been undertaken by either wind tunnel or numerical investigations of simplistic and isolated geometries. When field experiments have been undertaken, they have either been accomplished with a coarse network of in-situ sensors or slow response sensors based on timing or Doppler shifts, resulting in low resolution and decreasing performance with height. Multirotor small unmanned aerial systems (sUAS) are compact, have the ability to take-off and land vertically, hover for long periods of time, and maneuver easily in all three spatial dimensions. Hence, an instrumented sUAS provides not only a novel but also an effective platform that can be utilized to measure various properties in complex urban environments conveniently, cost effectively, and with high spatial resolution. This talk details observed three-dimensional kinematic properties of an urban boundary layer from a field campaign undertaken during the summer of 2019, and discusses the challenges associated with such an undertaking. In addition to providing new insight into the urban boundary layer, a better characterization of this environment is required for burgeoning sUAS urban operations such as urban air mobility and package delivery, amongst others.