Correlation between remote sensing data and ground based measurements for solar reflectance retrieving

• Remote sensing is a very useful tool to study UHI and characterize urban surfaces.
• We used remote sensing data to identify urban surfaces and to retrieve solar reflectance.
• A correlation between satellite remote sensing data and ground based measurements has been investigated.
• Measurements have been carried out on human-made urban surfaces.
• A good correlation between these measurements has been found (performing also a bootstrap analysis).

Surface and atmospheric modifications due to urbanization generally lead to the urban heat island effect (UHI). This phenomenon is an issue of growing interest and has long been studied by ground based observation. With the advent of remote sensing technologies, observation of UHIs became possible with airborne and spaceborne sensors. Remote sensing data allow urban surfaces characterization to study UHI mitigation methodologies such as the application of cool roofs and cool colors.In this study remote sensing data have been used first to identify urban surfaces and then to retrieve the solar reflectance value of these surfaces.The first area of interest is the city of Modena in the Emilia Romagna region (Italy). On this area orthorectified images by an airborne sensor are used. Available images do not allow to directly obtain the solar reflectance value. Therefore it has been investigated a correlation between satellite remote sensing data and ground based measurements.The solar reflectance was obtained for all urban surfaces of interest such as roofs and pavements. In this way it was possible to assess the real situation and to hypothesize achievable improvements in the solar reflectance of several urban surfaces aimed at improving thermal comfort and energy efficiency of buildings.