Beyond Fixed Instruments: Harnessing UAS Technology for Enhanced Wind Measurements in Meteorology and Wind-Energy Science

Abstract

The accurate measurement of wind patterns and profiles in the atmospheric boundary layer (ABL) is of great importance for a number of meteorological applica- tions, including weather forecasting, climate studies and environmental monitoring. Conventional techniques frequently encounter diffculties, including the necessity to rely on fxed instruments and the assumption of homogeneity in diverse topo- graphical settings. In light of these challenges, this research project investigates the potential applications of the emerging technology of uncrewed aircraft system (UAS) to atmospheric measurements and meteorology. UAS systems are known to be versatile instruments with flexible automatic mission planning capabilities, allowing rapid deployment to collect data in remote locations or in close proximity to sensitive structures. This study focuses on the measurement of the atmospheric wind vector through the use of both fixed- and rotary-wing UAS, addressing several aspects of these two inherently different flight systems. A low-cost technique for using any rotary-wing UAS as a sensor capable of measuring the horizontal wind vector is presented and analysed from several as- pects. The experimental results are presented and demonstrate the practicality and effectiveness of this method. This procedure, which is independent of the specifc rotary-wing system, has been applied to numerous UASs subsequently used for different research purposes. At the same time, the capabilities of the small fixed-wing UAS, the Multi- purpose Airborne Sensor Carrier-3 (MASC-3), for the validation of remote sensing instruments are analysed in detail using data from three different experimental campaigns. Both mean wind and turbulent component vectors are analysed to highlight the strengths and weaknesses of this approach for the validation of other stationary instruments. On a 10-minute time average, the UAS proved to be a good reference for stationary sensors even when flying over long horizontal distances, while the accuracy of turbulence measurements was found to be influenced by the heterogeneity of the terrain around the test site, with optimal results obtained where the terrain is flat and homogeneous and greater discrepancies where it is covered by forest patches. This finding emphasises the challenges and limitations associated with the use of UAS for atmospheric turbulence studies in heterogeneous landscapes. Overall, this thesis illustrates the potential of UAS technology as a versatile tool for atmospheric wind measurement, offering enhanced mobility and precision in various environmental contexts.