Evaluation and Comparison of Meteorological Measurements by a UAS with High-Resolution Numerical Weather Prediction Simulations

The performance of the meteorological measurements of an Unmanned Aircraft System (UAS) is studied in this paper by comparison with the simultaneous data collected by a wind mast, a radiosonde sensing package and ground-based, remote-sensing meteorological instruments at the radiosonde station of King’s Park, Hong Kong. They are found to meet the “breakthrough” level requirement of the World Meteorological Organization. The UAS is then used to collect meteorological data for the first time at a sandbox project location in Hong Kong for low altitude economy (LAE), namely, an area of complex terrain at an isolated island called Peng Chau. Some interesting features are identified in the vertical profiling flight of wind speed and turbulent kinetic energy (TKE), which forms the basis for developing meteorological support for LAE at this site in the future. High-resolution numerical weather prediction (NWP) simulation is then performed and evaluated statistically by comparison with UAS measurements at these two locations. The simulation of wind direction and TKE appears to be rather challenging as demonstrated in this comparison exercise. The root-mean-square-error of the simulated TKE is found to be of a similar order of magnitude as the absolute value itself, and the wind direction from the outer domain is found to have limited “correction” with the use of high-resolution terrain data in the NWP simulation with the mesoscale model. Further research directions for the simulation are discussed, with the objective of providing weather forecasting services for supporting LAE developments in Hong Kong.