Pollution radar

Leicester University has teamed up with Surrey Satellite Technology and EADS Astrium to create an air-quality measuring device that can be used as a ‘pollution radar’ over cities.

The Compact Air Quality Spectrometer (CompAQS) is one of the projects currently being developed at the UK's Centre for Earth Observation Instrumentation (CEOI). The device operates in the ultra violet and visible (UV/VIS) part of the spectrum to provide details of gases in the atmosphere.

Leading the project, Prof Paul Monks from Leicester University said: ‘The instrument has been developed for potential deployment as a small satellite payload and provides the performance of current, comparable instruments, which are significantly larger in size. Its compact size, achieved through the use of a novel optical design, means that the costs of manufacture, platform development and launch can be minimised.’

The team is currently working on two CompAQS instruments that will be constructed and configured for use as a ground-based Differential Optical Absorption Spectroscopy (DOAS) system at Leicester University.

The CityScan devices will operate in the VIS wavelength region to allow virtually real-time, 3D maps of atmospheric gases such as nitrogen dioxide to be constructed with five-minute time resolution.

According to the researchers, this can be achieved by the simultaneous analysis of scattered solar UV/VIS radiation from a range of instruments and multi-viewing geometries to give detailed information on the dynamics and composition of gases in the environment.

Each system is expected to provide coverage of areas of some 25km² and to undertake real-time monitoring of nitrogen dioxide and aerosol at a spatial resolution of 50m.

Monks said: ‘There is now overwhelming consensus that poor air quality has an impact on human health. The World Health Organization has estimated that 2.4 million people die each year from causes directly attributable to air pollution, with 1.5 million of these attributable to indoor air pollution. Population exposure to increased levels of gases and particulates requires action by public authorities at the national, regional and international levels.

‘Measurements of atmospheric composition and quality are important to both the long-term monitoring and control of human and naturally occurring emissions and the shorter-term effects on human health. There is an increasing need for data to be collected on a long-term basis, in more detail, over larger areas and with higher levels of consistency, with the CEOI playing a key role in meeting this challenge,’ he added.