Participatory Urban Monitoring from your Car

Detailed on-line measurements of city air quality are necessary to support compliance with air quality standards and emission strategy developments and to inform both policy makers and the general public in a timely manner. Current approaches to pollution monitoring, however, rely on very small numbers of stationary nodes. Providing detailed air quality information is a particularly hard challenge given the explosive and mostly uncontrolled growth of urban populations and the high cost of typically employed monitoring solutions. We present C3R, an alternative, participatory approach to urban air quality monitoring. C3R takes advantage of recent advances in vehicular ad-hoc networks and sensing technology. Vehicular networks provide an ideal platform for urban monitoring, with hundreds or thousands of potential nodes, freed from space and energy constraints, and reaching nearly every corner of modern metropolitan areas. C3R nodes, each equipped with low-cost pollution sensors and more standard location and communication devices, collect and disseminate pollution level information to other vehicles through a basic gossiping protocol. Each node maintains a real-time detailed air quality map that is shared with the driver, other vehicles and public agencies. We describe our current implementation of C3R and discuss some of the challenges we have addressed, including the adaption of solid-state pollution sensors to provide accurate measurements under dynamic vehicular conditions.