Modelling of air pollution around busy urban areas such as airports is a complex task. Ground stations for monitoring air quality and compliance reporting are usually limited in number, because of cost, to a few strategic locations. More recently given the advances in sensors, electronics and communication technologies it is now possible to design and build networked sensor nodes at a fraction of the cost of traditional systems. These breakthroughs in technology make it possible to implement large-scale sensor networks in city environments. A team led by Professor Rod Jones at the University of Cambridge, funded by NERC, is now doing just that for Heathrow Airport to better understand and develop sophisticated computer models for air quality in the vicinity of this busy international airport (Figure 1). Supporting the University of Cambridge are experts in sensors, electronics and computing at Imperial College, the Universities of Hertfordshire and Manchester, Cambridge Environmental Research Consultant and the National Physical Laboratory. An important collaborator in the project is the sensor manufacturer Alphasense Ltd.
The sensor nodes currently being installed around Heathrow include a wide array of sensors for measuring gases such as NO, NO2, CO, CO2, SO2, O3, VOCs and particle sizes of emissions. Sensor nodes in addition measure temperature, humidity and wind speed/direction and incorporate positioning (GPS) and communication electronics (GPRS) as shown in Figure 2. These networked sensor nodes are small enough form factor to enable them to be located easily on existing structures around the airport (Figure 3).
The network of nearly 50 sensor nodes will transmit environmental data in real-time via GPRS to a central database. Computer models will then combine on the ground sensor measurements with meteorological information as well as aircraft and road traffic data to predict air quality around the Heathrow Airport vicinity. A critical element of this proposal is the ability to detect the chemical signatures of individual aircraft movements.
The project is also supported by the British Airports Authority, who is assisting with the sensor network deployment and, in conjunction with British Airways, providing detailed information on aircraft movements.The specific objectives of the Heathrow project are:
Deployment of a pilot sensor network for a range of air quality metrics in and around Heathrow Airport using close-to-market, inexpensive field-based sensors and instruments, coupled to existing infrastructures such as GPS and GPRS.
Development of novel software tools for network calibration, analysis and data-mining, visualisation and interpretation.
Evaluation of the sensor network data against bottom-up emissions inventories and dispersion model results, leading to improvements in both.
Source attribution outputs for London Heathrow based on the sensor network system data and corresponding detailed data collection for emissions source activities during the measurement period.
Creation of a calibrated, high spatial and temporal resolution data set including NO, NO2, CO, CO2, SO2, O3, VOCs and size-speciated particle measurements for further scientific and policy studies.
Definition of best practice guidance in the design, configuration, deployment and operational management of networks of sensors for air quality studies and potentially in other environments.
At this time, approximately half of the sensor nodes have been installed at Heathrow and initial sensor data measurements are now being transmitted. By the end of 2012 the entire network of sensors should be fully operational.
The Heathrow project represents a new paradigm for making environmental science observations, as the high density of sensors enables a level of precision in modelling of air quality that has not been possible previously. It is anticipated that the outcomes from this work would have impact not only in terms of atmospheric science but also more broadly for operational aspects of the airport and potentially legislative implications when it comes to maintaining urban air quality standards.
If you would like to learn more about the Heathrow project please contact Professor Rod L. Jones, University of Cambridge at email@example.com or Tel: +44 (0) 1223 336466.
Figure 1: Location of Sensor Nodes Surrounding and Within the Heathrow Airport Complex
Figure 2: Close-Up View of Sensor Node Components
Figure 3: A Networked Sensor Node at Heathrow Airport (Inset shows close-up of module)