Monitoring Exhaust Emissions by Remote Sensing

NEMO includes the development of an autonomous remote sensing system to measure exhaust emission from road and rail vehicles under real driving conditions. Current remote sensing systems for air pollution monitoring use mainly infrared or ultraviolet light to detect pollutants. A laser technology for measuring exhaust emissions from traffic will be developed to monitor exhaust emissions ensuring better accuracy, sensitivity, stability, and cost effectiveness of measurements for long-term relevance of the technology as cars get cleaner. Finally, infrastructural integration will be in focus, enabling large scale dissemination of the technology into different urban environments.

The full remote sensing system will consist of a set of modules to provide a comprehensive emission profile from each passing vehicle. The main module is devoted to identifying the presence of certain tailpipe pollutants and their concentrations. Complementary modules are incorporated to record the vehicles’ speed and acceleration, to capture and identify the vehicle’s plate number, and a weather station to link the measurements to niche environmental conditions. Finally, an embedded computer will analyze the data in terms of pollutant concentrations and share it with a database.
Each pollutant absorbs light at different wavelengths. Therefore, measuring pollutants with laser technology works by analyzing and comparing the loss of light before and right after a vehicle has crossed a laser beam. Measuring pollutants with remote sensing technology is nothing new. However, current technologies cannot measure, with sufficient accuracy, the cleaner vehicles of the future, due to limited interaction between the laser and the gases or matter of interest and due to the inherent noise  of the system. The technology developed in NEMO will improve measuring methods in several ways. First, with lasers you can narrow down the spectra of which light is emitted and thus more accurately target specific gasses. Second, NEMO works to minimize the system noise, and hence create a measuring system, capable of detecting pollutants with an accuracy suited for the future. Finally, the laser technology is less vulnerable to external disturbances such as temperature and can therefor be calibration free, enabling autonomous and continuous monitoring, making the system much more cost effective, than existing ones.

Laser technologies developed and deployed builds on previous research performed by Opus Remote Sensing Europe, a European leader in the sector of the real time emissions monitoring and road traffic characterization. Laboratory validation of the technology has already been performed.  NEMO will take the technology to new levels through further testing of improved sensing devices. Validation will take place in the test site of the Joint Research Center in Austria, and then demonstrated in a real life urban environment. The laser technologies will be tested in Florence and Madrid for road vehicles, and in Valencia for trains.