Darpa Wants to Sniff Your City’s Distinct Chemical Scent
(WIRED) Don’t panic. But there’s a nontrivial chance terrorists will launch a chemical-weapon attack on U.S. soil. So the far-out researchers at Darpa are thinking about an unorthodox detection method: breathing in your city’s chemical bouquet. You’ve heard of racial and ethnic profiling? Here’s chemical profiling. Just imagine the privacy concerns.
In theory, chemical attacks can be detected before they happen. Even trace amounts of chemicals give off specific signatures that tools like sorbent tube samplers can register. But in order to figure out if dangerous chemicals are stockpiled somewhere or are floating through the air, the government’s going to have to know the baseline level for those chemicals wafting near your trash receptacle.
Darpa’s big idea, according to a new solicitation, is to collect trace elements of chemicals at different places in a city and then derive a model for determining that city’s chemical smell. It’ll have to vary with place, as high levels of petroleum-based chemicals are going to be more suspicious near a florist’s than at, say, a gas station.
Then Darpa wants researchers to represent the results in a “high-fidelity, three-dimensional chemical-composition map.” So-called “chemical cartography” is the first step in “identifying ‘dual-use’ substances with legal and illegal/illicit uses.”
For now, Darpa isn’t calling for any tools to actually track down anomalous amounts of chemicals. It just wants researchers to build models for chem maps, in order to prevent detection from becoming “prohibitively expensive” — that is, so guys with chemical-sampling canisters aren’t walking around each and every city block.
The data Darpa wants collected will include “chemical, meteorological and topographical data” from at least 10 “local urban sources,” including “residences, gasoline stations, restaurants and dry cleaning stores that have particular patterns of emissions throughout the day.”
Researchers will spend less than 30 minutes at each station taking chemical readings over a 48-hour period. Then they’ll adjust for atmospheric and environmental variables like wind speed, humidity and time of day — when, say, the dry cleaners’ is open to spew perchloroethylene vapor into the air — to account for the impact on chemical potency.
They’ll use that data to “predict concentrations down to trace gas concentrations of 10 parts per trillion” across a whole city. That’s where the maps get built.
They’ll have to include “labeled three-dimensional shape files for each focus area, as well as information about the types of infrastructure and activities present during data collection,” listing the “types of chemicals associated with various landmarks and activities.” And they’ll map fluctuations in chemical signatures across different times of year.
Of course, all this raises questions privacy concerns. Businesses and residents may not appreciate having Department of Defense-funded researchers taking chemical samplings on our near their property, especially for a project that will eventually go toward identifying would-be chem-terrorists.
The solicitation doesn’t have much interest in mapping areas of potential concern with much specificity. On the chemical maps, “labels may include ‘residential,’ ‘restaurant,’ etc.,” it reads.
“Useful metadata also may include imagery, databases of urban features (infrastructure, traffic patterns, etc.), and other sources of information.” But Darpa doesn’t say anything about who would own the maps or how they’d be used by the military, law enforcement or even regulatory agencies.
The Chemical Cartography project’s just in the beginning stages, so there’s no cash to hand out just yet. Darpa’s just seeking proposals for how researchers might build their models for the maps. They’ve got until Jan. 6 before Darpa decides who it wants to send sniffing around.