Airborne emissivity data to map the urban materials to be checked for maintenance: The asphalt paving and asbestos cement roofing case studies

This paper describes the suitability of airborne emissivity data to locate those materials noteworthy in an urban context. Among them, the test cases of asphalt roads and asbestos cement roofs were analyzed to individuate those where a maintenance intervention is required. To this aim, we first identify and select using a segmentation procedure the roads´ asphalt pavements and the asbestos cement roofs of an urban area in Italy covered by Multispectral Infrared Visible Imaging Spectrometer (MIVIS) imagery. Next, since both the asphalt pavement and the asbestos cement surface defects are strictly related to the decrease of their matrix, which causes an increase of the abundance of surfacing minerals showing diagnostic absorption emissivity peaks, these peculiar features were used for retrieving from MIVIS emissivities the sectors exhibiting defects on the material surfaces. The results showed that MIVIS data allow establishing a threshold that points out those asphalt road and asbestos cement roof sites that requires a maintenance intervention. Therefore, the proposed method can supply local government authorities an efficient, rapid and repeatable mapping procedure providing the location of the paving and roofing materials to be checked.