Antennae data sorts out land-mines

A new, high-speed mine detector that can locate buried land-mines to within half a inch was unveiled last week. Based on a phased array ground-penetrating radar developed by engineering researchers at Bristol University, it is said to be 1,000 times quicker than conventional probes and handheld devices.

The aim is to mount the detector on a boom sticking out from the front of a vehicle, such as a Land-Rover, and about two feet above the ground to avoid setting off trip wires.

The detector has been developed over many years by Dr Ian Craddock and Professor Ralph Benjamin, with funding from the Defence Evaluation and Research Agency. It uses a horizontal array of small antennae, each of which in turn transmits signals into the ground while the remaining antennae pick up the reflected signals.

A synthetic focusing technique is used to process the data received by each antenna in the array to enable the system to distinguish between mines, large stones and other debris.

Mathematical routines specially developed by the Bristol researchers greatly reduce the amount of computing power required to analyse the radar signals.

The university is in talks with defence group Racal with a view to manufacturing the system.