Friday, November 20, 2015

This Tool Could Sniff Out a Paris Bomb More Than a Football Field Away


Parisi­an po­lice moved in to ap­pre­hend people sus­pec­ted of launch­ing last week’s ter­ror at­tacks, a wo­man det­on­ated a sui­cide-bomb vest. The re­cent ap­pear­ance of such weapons in West­ern cit­ies has alarmed many in law en­force­ment. One pos­it­ive out­come of the mil­it­ary’s ex­tens­ive ex­per­i­ence with such devices is a new sys­tem that can help guards de­tect a bomb vest from up to 100 meters away.
The new ex­per­i­ment­al set of sensors is dubbed the Stan­doff Sui­cide Bomber De­tec­tion Sys­tem, or SS­BDS. De­veloped by the Joint Im­pro­vised-Threat De­feat Agency, or JIDA, it has already seen ac­tion; in 2012, the De­fense De­part­ment took an early ver­sion to Afgh­anistan.
The SS­BDS is not a single ma­gic lens, but an en­semble of sensors that meas­ure ra­di­ation at the mid­wave and long­wave in­frared as well as the tera­hertz wavelengths. There’s also a vis­ible-light cam­era. Tera­hertz ra­di­ation may sound like something to avoid—but be­cause it uses low en­ergy and isn’t ion­iz­ing, it’s less dan­ger­ous to hu­man tis­sue than x-rays. It has been used as part of se­cur­ity ap­plic­a­tions since 2004.
On Tues­day, JIDA of­fi­cials demon­strated the sys­tem to re­port­ers at Vir­gin­ia’s Fort Bel­voir. When dir­ec­ted at a per­son, the SS­BDS of­fers three views: a grainy black-and-white, which is the in­frared; a bright or­ange glow, which is the tera­hertz; and a reg­u­lar pic­ture from the cam­era.
The pres­ence of a sui­cide belt won’t set off alarms but a trained—or simply at­tent­ive—eye can use the mul­tiple sensors to see dark shapes or spots—areas of neg­at­ive space that in­dic­ate an ab­nor­mal­ity, which should prompt a closer in­vest­ig­a­tion. In es­sence, you’re look­ing not for ex­plos­ives but for holes in the pic­ture where there should be sol­id white or or­ange.
The SS­BDS is not a small sys­tem. Each bank of sensors stands at per­haps three feet tall, and a hand­held ver­sion would be prac­tic­ally im­possible. “You’re lim­ited by phys­ics,” said an­oth­er one of the De­fense De­part­ment sci­ent­ists on the team. But it could be in­cor­por­ated in­to the ar­chi­tec­ture of a train sta­tion, foot­ball sta­di­um, or con­cert ven­ue.
In JIDA’s demon­stra­tion, which was modeled on a real-world test­ing scen­ario, a base in Afgh­anistan, a sub­ject, dressed in a thawb, or white dress­ing gown, stood in a booth. The booth shiel­ded him from sun­light, which can in­ter­fere with the tera­hertz sensor—which points out just one of the dif­fi­culties in turn­ing the SS­BDS in­to a use­ful, de­ploy­able sys­tem.
The next step for SS­BDS, if its re­ques­ted re­search-and-de­vel­op­ment money comes through, is the in­teg­ra­tion of a new, cut­ting-edge sensor for hy­per­spec­tral ima­ging. Take a thermal im­age of the sort you would see with a heat cam­era and then slice it up in­to dif­fer­ent wavelengths, al­low­ing op­er­at­ors to identi­fy not just dark spots but also, po­ten­tially, the pres­ence of ex­plos­ives. That would cut down on false pos­it­ives and in­crease the range of the device.
“We can take dif­fer­ent ma­ter­i­als, such as your jack­et, my jack­et, her shirt. Al­though they’re very sim­il­ar in ma­ter­i­al makeup, they ac­tu­ally have their own unique sig­na­tures, so every piece of ma­ter­i­al has its own sig­na­ture, just like a fin­ger­print,” said a third sci­ent­ist.
The cost of a pro­duc­tion sys­tem could run past a mil­lion dol­lars, but those num­bers could come down as man­u­fac­tur­ing comes up since all of the sensors are com­mer­cial off-the-shelf.
SS­BDS wasn’t in­ten­ded for use in a ci­vil­ian set­ting or a West­ern city but to pro­tect troops on for­ward op­er­at­ing bases. But the need for sys­tems like it has evolved tre­mend­ously—and rap­idly.
On Fri­day even­ing, just 15 minutes in­to a soc­cer match between France and Ger­many, a man wear­ing a vest laced with ex­plos­ives ap­proached one of the en­trances to the St­ade de France, a sta­di­um filled with 80,000 spec­tat­ors in­clud­ing French Pres­id­ent François Hol­lande. When guards frisked him, he backed away and det­on­ated the vest.
New York City Po­lice Com­mis­sion­er Wil­li­am Brat­ton seized on this as an omin­ous sign of the fu­ture: “All of them, were equipped with these sui­cide vests, which are a great con­cern if you’re ask­ing your of­ficers to rush in, which is the tac­tic here in Amer­ica now, [when] re­spond­ing to the act­ive-shoot­er scen­ario,” he said on the pop­u­lar Morn­ing Joe news pro­gram.
No sensor sys­tem can re­place the judg­ment of an in­tel­li­gent and ob­ser­v­ant hu­man be­ing, a be­ing, hope­fully, armed with the best equip­ment. The events last week and this week in Par­is are test­a­ment to that.

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