The Pentagon's fringe science arm wants to keep track of potential enemies-of-the-state in every way imaginable: not just by sight, or by sound, or by their e-mail; but by their smell, as well.Darpa's "Unique Signature Detection Project (formerly known as the Odortype Detection program)" aims to sniff out genetic markers in "human emanations (urine, sweat, etc.)" that "can be used to identify and distinguish specific high-level-of-interest individuals within groups of enemy troops.""Recent experimental results" show that chemical compounds in a mouse's "urinary" scent produces an "odortype" that's unique to each individual rodent, Darpa observes in its original solicitation for the project. "Although experimental data for humans is far less quantitative," the agency is hoping that a similarly "genetically determined," "exploitable chemosignal" can be found in people, too.Once that marker is found, Darpa's proposed 2007 budget notes, the agency wants to know what "the impact of non-genetic factors (e.g., diet, stress, health, age) [have] on the signal." That could help figure out how to "robustly extract" the signal "from a complex and varied chemical background."The sniffing-out process has already begun in the lab, one professor told Business Week last year. A person's smell "is a cocktail of hundreds of molecules... The question is whether it's a gin and tonic or a margarita." Making those distinictions out in the odorifically-complex real world won't be easy, he added.Darpa's smell detector is part of a larger, $15 million-per-year effort to develop "novel sensors" for U.S. troop operating in "urban settings." The goal of the Urban Vision program is "to enable the warfighter to 'see' movers within a building using a variety of fused multi-spectral techniques." The "Enemy Dismount Intrusion Detection program," on the other hand, "will develop a chemical sensor that is capable of providing an advanced warning of the presence of enemy troops or combatants by detecting the chemical emissions... that are common to all humans."And this effort is, itself, only a small part of Darpa's ongoing push to "observe our adversaries and their environment 24 hours a day, seven days a week, week-in and week-out and that implies a multiplicity of platforms, sensors and sensor types on the ground, in the sea, in the air, and also in space," explained the agency's Dr. Ted Bially in a recent speech. Other components include the development of a giant blimp that can watch over an entire city at once, a network of minature sensors which spot adversaries using radar, and software programs that comb for potential terrorists in the web traffic and e-mails of ordinary people.UPDATE 04/18/06 8:01 AM: In the comments, Jutta posts a transcript of an old Voice of America broadcast, which notes that:
DURING THE COLD WAR, THE STASI [East German secret police] ALSO KEPT WHAT MR. LEGNER DESCRIBED AS "SMELL SAMPLES" OF PEOPLE -- CLOTH SAMPLES CONTAINING THE SCENT OF INDIVIDUALS THAT COULD BE USED FOR DOG TRACKING AND IDENTIFICATION PURPOSES. WE FOUND THESE SAMPLES IN SEALED GLASS BOTTLES.