Development of a Meteorological Sensor Suite for Atmospheric Boundary Layer Measurement Using a Small Multirotor Unmanned Aerial System

Small unmanned aerial systems (sUAS) are increasingly being used to conduct atmospheric research. Because of the dynamic nature and inhomogeneity of the atmospheric boundary layer (ABL), the ability of instrumented sUAS to make on-demand 3-dimensional high-resolution spatial measurements of atmospheric parameters makes them particularly suited to ABL investigations. Both fixed-wing and multirotor unmanned aircraft (UA) have been used for ABL investigations. Most investigations to date have included in-situ measurement of scalar quantities such as temperature, pressure and humidity. When wind has been measured, a variety of strategies have been used. Two of the most popular techniques have been deducing wind from inertial measurement unit (IMU) and GPS calculations or measuring wind making use of multi-hole pressure probes. Derived calculations suffer from low refresh rates and multi-hole probes have a finite cone of acceptance for flow angles and are limited in accuracy below a minimum requisite velocity. Hence, a hovering multirotor UA, conducive to making measurements at a specific point or within an obstacle-laden environment, may not be able to accurately measure modest atmospheric winds using these strategies. This work details the development of an instrumentation suite for the measurement of scalar atmospheric parameters and atmospheric winds, along with the ability to telemeter data. The 3-dimensional wind measurement solution is accomplished using two compact and robust orthogonally mounted acoustic resonance anemometers for a 3-D wind measurement solution that enables the measurement of atmospheric winds while hovering