Applicazioni del telerilevamento termico da piattaforma satellitare ed aerea per aree urbane

The work deals with the employment of tools and techniques of thermal remote sensing from satellite and aerial platforms in urban areas. Thermography at city scale from satellite platforms is firstly discussed, with particular emphasis on the assessment of the Urban Heat Island phenomenon: different methods for the atmospheric corrections, the estimation of emissivity and the calculation of the Land Surface Temperature are dealt with. Afterwards an experimentation performed over the urban area of Bologna using ASTER images is described: the results show the presence of an Urban Heat Island in the study area, although its magnitude is difficult to estimate. The Central Europe Energycity Project - aimed at developing a GeoWeb Spatial Decision Support System as regards the reduction of energy consumption and greenhouse gas production in seven cities of Central Europe - is later introduced, describing the procedures for aerial and ground surveys and the processing workflow of digital datasets to create maps of roof surface temperature. Finally the experimentation performed on the city of Treviso using thermal aerial imagery acquired in winter 2010 is described, with the creation of a georeferenced mosaic of brightness temperature by means of both geometric and radiometric corrections. The results show that accurate surface temperature measurements may be obtained only by the implementation of different processing stages and after the exact assessment of emissivity values; moreover, knowing the spectral band of acquisition of the thermal sensor proved to be essential.