Air pollution mapping by portable sensors and DGPS positioning

In 1994 we applied the satellite positioning method to environmental monitoring (Camus et al., 1994, Cefalo P.,1996). A Carbon Monoxide electrochemical sensor was mounted on a car together with a GPS positioning sensor. The car was driven along the streets of Trieste center and the concentration of this gas was measured every two seconds. By properly choosing the urban route with crossing streets, the data were processed in the form of contour levels, so allowing a mapping of the CO concentration. The data were also processed as street pollution profil es. The sensor has a delayed response of about 9 seconds. Moreover, the CO concentration as measured outside a vehicle suffers a lot of transient peaks due to the exhaustion of any car or motorbyke close to the sensor. Nevertheless immediatly repeated passages on the same street displayed the same concentration within 20%, which is quite a significant result if the measurement campaign is devoted to alert authorities and people of the dangerous pollution.