No matter how well a terrorist covers their tracks, or how cool they are under pressure, the Pentagon wants to be able to detect, track, and even positively identify them from a distance. And they want to do it using nothing more than the heat and sweat that emanate from a person's pores.

The military's been after scent-based detection systems for years now. In 2007, Pentagon research agency Darpa solicited proposals for sensors to sniff out terrorists using unique genetic markers found in human emanations. The idea was based on research showing that mice each carried a unique "odortype" that was consistent despite variables like stress, hydration or diet. And odortypes are so powerful, they stick around for around a month after their host body has fled the premises.

But the most state-of-the-art tech, known as E-Nose, has only succeeded in distinguishing between two different people, and relies on "detecting human odor from the armpit region." Now, the Army is launching Identification Based on Individual Scent (IBIS), and wantsproposals for a more sophisticated detection system, that could "uniquely identify an individual based on scent," at a geographical distance or after several hours or even days.

That's no easy task – in 2005, one professor described human odor as "a cocktail of hundreds of molecules," – but the Army envisions myriad civilian applications for the tech, including "identifying and tracking persons from the scenes of various crimes."

The Army's also launching "Human Signature Collection and Exploitation via Stand-Off Non-Cooperative Sensing," to refine technology that can detect hostile intent based on thermal imaging – an analysis of the heat radiating off a body. And since research has shown that different faces radiate heat in unique patterns, they're hoping to create sensors that can positively identify people, much like iris scans or fingerprinting.

The idea would be particularly useful in urban war-zones, where troops are often forced to pick threats out of a crowd, recognize dangerous groups or clue into the nefarious intent behind seemingly benign behavior. The Army's project would allow troops to simultaneously ID potential threats and detect "aggression or hostile intent" – all at a safe distance from any insurgent armpits.

[Photo: chowchow52 / webshots]