The testing was part of DARPA’s SIGMA+ program, which calls for the development of new sensors and networks that would alert authorities to chemical, biological, and explosives threats. During the recent test, the agency collected more than 250 hours of daily life background atmospheric data across five neighborhoods that helped train algorithms to more accurately detect chemical and biological threats.
The testing, says the agency, marked the first time in the program the advanced laboratory grade instruments for chemical and biological sensing were successfully deployed as mobile sensors, increasing their versatility on the SIGMA+ network.
"Spending a week gathering real-world background data from a major Midwestern metropolitan region was extremely valuable as we further develop our SIGMA+ sensors and networks to provide city and regional-scale coverage for chem and bio threat detection," says Mark Wrobel, program manager in DARPA's Defense Sciences Office. "Collecting chemical and biological environment data provided an enhanced understanding of the urban environment and is helping us make refinements of the threat-detection algorithms to minimize false positives and false negatives."
In addition to collecting more than 250 hours of chemical and biological background environment data, DARPA researchers also evaluated the sensors’ performance in detecting benign controlled chemical releases that could be representative of threat agent production processes. Five safe chemicals were released and tracked by the sensor platforms during the week.
One such chemical, says the agency, is acetone, which has benign industrial and business uses but can also be used for nefarious purposes.
"We tested the ability of the sensors to distinguish between normal background chemical environment and small traces of specific chemicals such as acetone," says Wrobel. "If a chemical sensor makes an acetone hit near a nail salon, the SIGMA+ data analytics can help authorities make a determination that it's probably a benign use of the chemical. But if an anomalous concentration of acetone is picked up at a location with no logical connection