Tag Archives: acoustic fingerprints

Biometrics Run Amok: Your Heartbeat ID, please

Before pulling the trigger, a sniper planning to assassinate an enemy operative must be sure the right person is in the cross-hairs. Western forces commonly use software that compares a suspect’s facial features or gait with those recorded in libraries of biometric data compiled by police and intelligence agencies. Such technology can, however, be foiled by a disguise, head-covering or even an affected limp. For this reason America’s Special Operations Command (SOC), which oversees the units responsible for such operations in the various arms of America’s forces, has long wanted extra ways to confirm a potential target’s identity. Responding to a request from soc, the Combating Terrorism Technical Support Office (CTTSO), an agency of the defence department, has now developed a new tool for the job.

This system, dubbed Jetson, is able to measure, from up to 200 metres away, the minute vibrations induced in clothing by someone’s heartbeat. Since hearts differ in both shape and contraction pattern, the details of heartbeats differ, too. The effect of this on the fabric of garments produces what Ideal Innovations, a firm involved in the Jetson project, calls a “heartprint”—a pattern reckoned sufficiently distinctive to confirm someone’s identity.

To measure heartprints remotely Jetson employs gadgets called laser vibrometers. These work by detecting minute variations in a laser beam that has been reflected off an object of interest. They have been used for decades to study things like bridges, aircraft bodies, warship cannons and wind turbines—searching for otherwise-invisible cracks, air pockets and other dangerous defects in materials. However, only in the past five years or so has laser vibrometry become good enough to distinguish the vibrations induced in fabric by heartprints….

Candice Tresch, a spokeswoman for the cttso…. cannot discuss the process by which heartprint libraries might be built up in the first place. One starting point, presumably, would be to catalogue the heartbeats of detainees in the way that fingerprints and dna samples are now taken routinely.

Excerpts from Personal identificationPeople can now be identified at a distance by their heartbeat, Economist, Jan 23, 2020

Fiber Optic Cables and Surveillance

[T]he technology known as distributed acoustic sensing (DAS)… allows underground fibre-optic cables, like those used by telecoms companies, to be turned into a giant string of microphones. They can then be used to monitor all sorts of sensitive locations, from oil and gas pipelines to railway tracks, military bases and international borders. In its latest guise, DAS is even being used to help make hydraulic fracturing, or “fracking” as it is known, more efficient at releasing natural gas and oil trapped in rocks.

There are some limitations to the technology. Its powers of hearing are not sufficiently acute to pick up a conversation, for example. And since the cables inside buildings are typically a tangle of short lengths interrupted by junction-boxes, it is unlikely to work there. However, a long cable buried outdoors can provide the equivalent of a microphone every ten metres.  Algorithms are used to establish acoustic “fingerprints” for the sounds that are detected; and depending where and when they occur, each is assigned a level of risk, says Magnus McEwen-King, OptaSense’s managing director. Footsteps around a guarded facility at midday may not be unusual, but at 2am they would be.

OptaSense is also using the system to monitor sounds coming from below ground, in particular those produced by the water, sand and chemicals pumped under high pressure to fracture rock during fracking. There is concern about exactly what is going on underground, and in particular if the process might contaminate aquifers. Various seismic sensors can be used to monitor the fracking process, sometimes from test bores drilled nearby. But it is a costly and tricky process.

Shell and other oil companies are using a DAS system, which OptaSense calls vertical seismic profiling, to monitor their fracking. It uses a fibre-optic cable inserted into a well bore to build up an acoustic picture of the fracking fluid going into the rock at multiple levels. This means that potential problems, such as blockages, or leaks from one layer of rock to another, can be spotted before they become serious. And by having a clearer idea of how much fluid is going where, the fracking process can be constantly adjusted so that it runs in the most efficient way.

Listening for intruders and monitoring the efficiency of fracking are just two of the potentially lucrative applications of DAS technology. No doubt there will be others in the pipeline.

Acoustic sensing: The ear underground, Economist,  January 4, 2014, at 62