Microwave imaging

Microwaves could provide a safe new way of finding hidden weapons and buried mines, thanks to UK research.

Scientists in the UK are developing a microwave-based technique that can generate high-quality images of hidden objects. The research may lead to the use of microwaves as an alternative to X-rays in airport security checks, building searches, landmine detection and other applications.

The work is being carried out by a team of engineers and physicists at Northumbria University, with funding from the Engineering and Physical Sciences Research Council (EPSRC). Although technically viable, microwave imaging systems will only see widespread deployment if they can produce results quickly and cheaply. To tackle this key barrier, the technique being developed by the new EPSRC-funded project will comprise a two-stage process.

The first involves the use of conventional detectors to measure the 2-dimensional pattern made by the scattering of microwaves when they come into contact with a hidden object. At the moment, the researchers are using a power meter to detect the microwave energy, which is less than 5mW, but later they hope to use basic microwave detector diodes.

The second stage of the process takes the data and uses computer software to construct a 3-dimensional image from it. At the present, the researchers are using their own home-brewed software, but as the research progresses they hope to work with commercial image processing software vendors to develop the software further.

The new technique aims to avoid the need to use complex one-stage equipment that produces images slowly and at considerable expense. Dr. David Smith, from the University’s School of Engineering and Technology, is leading the project. He says: ‘The technology could be very versatile and suited to use in security, medical and industrial applications. Although we are just at the beginning of this research, our ultimate aim is to offer an alternative, fast 3D microwave imaging technique which can be used across a wide range of disciplines.’