Usefulness of UAV-mounted multi-sensor system for in situ atmospheric measurement: a case study from Wrocław, Poland

Air pollution, especially particulate matter (PMx), is one of the most serious environmental threats worldwide. It is challenging in terms of both public health, impact on climate, and the reduction of visibility. The assessment of spatial variability of PMx allows us to understand better the processes causing the smog episodes, and may also be an additional element for the validation of the results of dispersion models. The study presents the results of measurements of basic meteorological parameters and air pollution, involving the multi-sensor system and conducted in a vertical profile. A Matrice 600 hexacopter with installed environmental head was used as the measurement platform. This system is a prototype solution, developed in cooperation between the University of Wrocław and the Optimum Tymiński company. This system enables us to measure the concentrations of PM2.5, PM10, air temperature and humidity. Additionally, all flight parameters are recorded. All data are registered with 1 second time resolution. The measuring head is placed at the top of the device, above the rotors plane. Measurements were carried out in Wrocław (Poland), both in the warm and cold season in 2019-2020, in areas with different land use and emission structure. The main objective of the research was to analyze the variability of the concentration of particulate matter and temperature gradients in the vertical profile up to a height of 350 m above the ground. The mobile data were supplemented by information obtained at the Meteorological Observatory of the University of Wrocław (e.g. sodar echos from acoustic sounding system). In-situ measurements involving UAVs as a mobile platform and high-resolution sensors indicate the usefulness of this method in atmospheric research, providing reliable information on temporal and spatial variability of air quality and temperature. These data can complement both traditional and remote sensing measurements.