This article was taken from the September 2014 issue of Wired magazine. Be the first to read Wired's articles in print before they're posted online, and get your hands on loads of additional content by <span class="s1">subscribing online.
We're not just being monitored by drones and cameras: networks of spies are now hiding in fake rocks. The Self-Powered Ad-hoc Network (SPAN), built by US aerospace and technology company Lockheed Martin, is a sensor net that can guard borders and other sensitive military locations 24/7. "We've seen how this technology can be used in overseas operations," says Lockheed Martin's business development manager Alex Moore. "You can cover an area without having people in there at all."
Each SPAN sensor is hidden in a 3D-printed "rock" and contains a solar cell that can generate enough electricity to power the device indefinitely. Moore says it can estimate the number of people in a group on foot, distinguish humans from animals and even recognise vehicle types. The system only sends summary information, so power requirements are tiny. The plug-and-play design also means that other types of sensors, such as magnetic, chemical-sensing or olfactory "sniffers" can be incorporated as needed. "The sensors keep getting smaller and cheaper," says Moore. "Eventually we'll be able to scatter them like breadcrumbs." Leave no stone unturned... \1. VIBRATION
Passing vehicles and people produce ground vibrations and sound waves through the air \2. DETECTION
Palm-sized sensor nodes hidden in fake rocks detect and log the waves and vibrations \3. CONNECTION
Up to 20 nodes automatically connect and pass on data in a mesh network \4. TRANSMISSION
A gateway node sends data back to a base operator via satellite link, Wi-Fi or UHF radio \5. COMMUNICATION
Operators receive data as messages: "moving pickup truck at these GPS co-ordinates..."
This article was originally published by WIRED UK
