Satellite data for the air pollution mapping over a city – The use of virtual stations

International audienceAtmospheric pollution becomes a critical factor of anticipated deaths, which concerns ambient air quality as well as air quality in houses and places of work. For the well being of human and for the population information, we need to evaluate the actual exposure of persons to ambient pollution. One way to perform it is to evaluate the space time budget of air pollution exposition. Hence an information on the spatial distribution of pollutant concentrations is required. Several tools exist; most of them provide maps of pollutant concentrations but over a regional scale with a grid of 1 km, which is insufficient. Measuring stations, scarcely distributed in the city, provide a complete surveillance but their costs limit the knowledge of pollutant concentration to specific points of the city. To overcome this problem, several notions are defined: “identity card of a measuring station”, “pseudostation” and “virtual station”. Based on a multi-sources approach, this paper presents a methodology using remotely sensed data for the mapping of pollutant concentrations over a city