UAV-Based Monitoring of the Thermal Structure of Heterogeneous Landscapes

This paper presents a technique for measuring the temperature of an inhomogeneous underlying surface using unmanned aerial vehicles (UAVs). To test the proposed technique, measurements over various landscapes are presented: dunes in an arid zone, a temperate swamp, a subarctic city, and a combination of natural and anthropogenic landscapes in the Arctic. A measuring complex based on a DJI Mavic 2 Zoom quadrocopter with a Flir TAU 2R thermal camera is used. Methods for correcting emerging hardware errors and artefacts have been developed. To obtain detailed data on the spatial distribution of the surface brightness temperature, the orthomosaic construction method is used. Thermal maps of surfaces with surface height inhomogeneities (dunes), moisture inhomogeneity (swamps), and urban areas in polar and subpolar conditions are obtained at different times of the day. It is shown that thermal contrasts can reach the first tens of degrees Celsius within an area of 10–20 ha, both under the background of daytime heating and nighttime cooling of the surface, and could have a significant effect on the spatial distribution of the heat transfer characteristics of the atmosphere and the underlying surface. These methods are recommended for constructing surface thermal maps using thermal imaging technology.