A methodology for acquisition and processing of thermal data acquired by UAVs: a test about subfluvial springs’ investigations

An accurate description of watercourses helps to easily understand their behaviour both for routine hydrological investigations and in disasters cases. Knowing the position and the dimension of the supply sources of the river is crucial, since they have a direct influence on its behaviour; however, they are not often easily identified, and almost always completely unknown. Aerial thermal data can be critical in order to rapidly reveal and map the river supply source points for extensive areas. Using unmanned aerial vehicles (UAVs) to collect very easily and quickly high-resolution information is thus very interesting. UAVs can house many sensors for performing investigations in different bands of the spectrum, including thermal data. This work explains how UAVs can be used to collect this kind of data (through RGB and thermal devices) and presents a strategy to easily integrate the information from these different sensors. Integration procedures, also applicable in emergency situations, were developed. These methods do not require points on the ground and can be performed using commercial devices.