ERA Technology's surface penetrating radar has been used to assist police forces in the course of criminal investigations, notably at 25 Cromwell Street. This work developed from a research project carried out in the mid 1980s on behalf of the UK Home Office Police Scientific Development Branch and various tests were used to establish the capability of the technique. In 1994 Gloucestershire Police used specialist Surface Penetrating Radar equipment, provided by ERA Technology, of Leatherhead, Surrey (UK), to help identify the possible locations of buried human remains, at the West family home in Cromwell Street, Gloucester.

ERA Technology first produced this equipment following work it undertook for the UK's Ministry of Defence, to evaluate the different means available of detecting plastic mines left buried in the ground after the Falklands conflict. ERA concluded that Surface Penetrating Radar was the most effective method. The company subsequently received a contract from the MOD to build a Surface Penetrating Radar unit and operate the equipment on the Ministry's behalf in the Falklands.

The equipment has also shown itself to be ideal for other non-destructive testing applications. These include: archaeology, for detecting possible locations of ancient burials and artefacts; civil engineering, for searching for voids in certain types of reinforced concrete or for locating pipes and cables underground; and for searching for avalanche victims. Because of its success in these broadly similar applications, the police decided to call in ERA Technology's Surface Penetrating Radar, to help with the investigation in Gloucestershire.

A major advantage of the radar over other non-destructive testing methods such as ultrasound is that it is possible to use an antenna (transducer) that is not in physical contact with the material being tested. Thus it is technically feasible to scan areas of interest extremely quickly (up to 30 km/h).

The equipment works on standard radar principles i.e. by detecting back-scattered energy from a target; anomalies within a material give rise to reflections, which are detected by the receiving antenna. Conventional radar can be considered to be stationary and its target mobile, whereas the surface penetrating radar moves and its targets are stationary.

The SPR's transmitting antenna, housed with the receiving antenna in a container, is pulled over the surface in question. At the same time it sends into the substance under investigation a very low power pulse of energy, in the microwave frequency region. The equipment is compliant with European CE standards.

For further information contact: david.daniels@era.co.uk