March 30, 2018 - 2:00 pm
March 30, 2018 - 3:00 pm
Address120 David L. Boren Blvd., Room 5600, Norman, OK 73072 View map
Boundary Layer Profiling Using Rotary-Wing Unmanned Aircraft Systems: Filling the Atmospheric Data Gap
The planetary boundary layer (PBL) is comprised of energy exchanges with the Earth’s surface, and as such plays a large factor in the evolution of weather conditions. However, traditional methods of observing the atmosphere, such as radiosondes and surface weather stations, drastically underrepresent processes occurring in the PBL. More recently, surface-based remote sensing capabilities have advanced, but these instruments are often expensive and difficult to implement across large scales operationally.
The capabilities of small unmanned aircraft systems (sUAS) to make atmospheric observations is rapidly being realized as a means to collect previously unobtainable observations in the lowest part of Earth’s atmosphere. However, in order for these systems to provide meaningful kinematic and thermodynamic data, it is imperative to establish an understanding of the strengths and limitations of the sensors and retrieval algorithms implemented, as well as how they perform under various configurations and flight conditions. This initial objective is comprised of two experimental stages, the first of which is calibration of thermodynamic sensors against reference measurements from the Oklahoma Mesonet and the National Center for Atmospheric Research in order to understand response characteristics in quasi-ideal environments. Furthermore, efforts have been made to calculate horizontal wind fields using Euler angles derived from the rotary-wing’s autopilot. The second stage is validation of these sensor performances once mounted onto a rotary-wing sUAS by comparing measurements with instrumented towers, radiosondes, and other sUAS. It appears that these measurements are robust provided that instrument packages are properly mounted in locations that provide adequate air flow and proper solar shielding.
Once a platform’s atmospheric sensing capabilities are optimized, its utility has been proven in applications from the diurnal boundary layer transition and turbulence to providing forecasters with quasi-real time profiles in convective environments deemed by the Storm Prediction Center (SPC) to be of highest risk for severe thunderstorms and tornadoes. After addressing the development of platforms by the Center for Autonomous Sensing and Sampling (CASS) at the University of Oklahoma (OU), results from the recent field campaign Environmental Profiling and Initiation of Convection (EPIC) will be discussed. This campaign demonstrated the potential for sUAS to improve forecasting abilities and our understanding of the atmosphere, in addition to gaining national media attention. This is only just the beginning of tapping into the serviceability of rotary-wing sUAS for atmospheric sciences, and this presentation will conclude with an outlook for future possibilities.