CityScan - The Pollution Radar

During 2011 two new CompAQS spectrometers are being constructed and configured for use as a ground-based Differential Optical Absorption Spectroscopy (DOAS) system by the University of Leicester, in collaboration with partners at Surrey Satellite Technology Ltd. These CityScan instruments will operate in the visible wavelength region to enable virtually real-time, 3D maps of atmospheric gases such as nitrogen dioxide to be constructed with five-minute time resolution.

The CityScan Instrument

This is achieved by the simultaneous analysis of scattered solar radiation from multiple instruments and multi viewing geometries, giving an unprecedented level of information on the dynamics and composition of the urban environment.   The CityScan instrument will have significant advantages over currently available air quality monitors, providing a continuous monitoring technique for an entire urban area. Each system is envisaged to provide coverage of areas of some 25 square kilometers and to undertake real-time monitoring of nitrogen dioxide and aerosol at a spatial resolution of 50 meters.

CityScan footprint using 2 instruments

These instruments effectively act as a pollution radar.

CityScan will enable the collection of unique air quality monitoring datasets with the potential to open up new areas in emission monitoring, pollution measurement and air quality control. Such measurements need high performance spectrometer and detector systems, sharing a number of key development demands with satellite instrumentation.

Some links to recent press-releases and articles.

A good starter for information - A 2011 poster presented by Rosie Graves on the CityScan instrument

Please contact Roland Leigh ( or Paul Monks ( for more information

Some background information on the techniques used in this new technology can be found in the following pages.

Roland Leigh's University of Leicester website

The University of Leicester's Air Quality group website

The Centre for Earth Observation Instrumentat website- CompAQS spectrometer page

Locations of visitors to this page

last updated: 13th June 2011.