Planetary Boundary Layer (PBL) Structure Influences on the Functionality of Airborne Sense and Avoid (ABSAA) and Ground Based Sense and Avoid (GBSAA) Systems for Small Unmanned Aircraft Systems (sUASs)

The Federal Aviation Administration (FAA) Center of Excellence (COE) Alliance for System Safety of Unmanned Aircraft Systems (UAS) through Research Excellence (ASSURE) is focused on safely integrating small Unmanned Aircraft Systems (sUASs) into the National Airspace System (NAS).  The University of North Dakota, through ASSURE, is evaluating Detect and Avoid (DAA) systems that would enable sUASs to operate within the NAS without the need for ground observers or chase planes.  However, atmospheric conditions can pose significant hazards for such systems.  Planetary Boundary Layer (PBL) structures, for instance, influence electromagnetic and acoustic propagation, which impacts both intruder location accuracy and detection likelihood.  To evaluate potential impacts of PBL structures on DAA systems, electromagnetic ray tracing is performed using refractive indices from High Resolution Rapid Refresh (HRRR) output provided through the Pennsylvania State University’s Bufkit dataset.  Additionally, to the extent possible, acoustic propagation is also being considered.  Results include both impacts and how such impacts can be mitigated.