Bomb sight

Suicide bombers could be spotted in a crowd before they carry out their deadly mission, thanks to a combination of ultrawideband radio technology and an obscure law of physics, according to a UK project team.

Researchers at Birmingham University and the UK R&D division of Thales hope to develop portable sensors based on UWB to detect hidden weapons and explosives in an open area without having to channel people though security gates — which is a major logistical headache.

Tests have already identified a grenade-shaped object hidden in a pocket, and the system could eventually even be able to distinguish between different types of weapons, according to researchers evaluating the technology.

The system uses one-nanosecond radio pulses from a UWB sensor that occupy the 1GHz band.

UWB sensors are not new in themselves, but the research team, based in Birmingham’s engineering department, plans to use a littleknown principle of physics known as Late-time Response (LTR) to analyse the signals.