Techniques, tools and workflow for remote sensed roof temperature mapping in some cities across Central Europe

For the application of the energetic building models planned in the Central Europe EnergyCity project, an accurate mapping of surface temperature of roofs is necessary; by means of aerial and ground surveys, and after several processing phases, it is possible to obtain temperature values that will be implemented in the model for energy efficiency evaluation. Aerial thermal imagery must be firstly converted in at-sensor radiance; then the strips must be orthorectified and mosaicked in order to obtain a single overall image for each city involved, that, after radiometric corrections, emissivity assessment and the inversion of Planck’s Law, can be transformed in orthorectified maps of surface temperature. For each of these phases some parameters not obtainable by remote sensing techniques are required: the level of approximation and the quality of outputs depend much on the characteristics of additional datasets available.