THERMOGRAPHIC CHARACTERIZATION OF A LANDFILL TROUGH AN UNMANNED AERIAL VEHICLE

The use of the thermal imaging camera for Unmanned Aerial Vehicle (UAV) survey is to date very common for environmental analysis, especially if high spatial resolution images are required. Some analyses require images to be acquired close to sunrise, to avoid the influence of the incident solar radiation on the surface temperature, as in the case of a landfill survey. Indeed, thermal anomalies due to generated landfill biogas can be characterized once other heat sources are excluded. In this framework, thermal images need to be processed similarly to optical images by typical photogrammetric workflows producing both a Digital Surface Model (DSM) and an ortho-image. The low spatial resolution of thermal cameras, optical distortion and low and homogeneous spatial distribution of radiant exitance at sunrise require, however, an adapted workflow. In this work, some first tests were carried out at a landfill in Palermo (Italy) to evaluate the feasibility of using thermal images to determine the DSM and the thermal orthoimage of the area, aiming to identify thermal anomalies related to landfill heat sources such as biogases.