If you were heading into a burning, smoke-filled building, you'd probably want someone else to know your location within it at all times. German scientists have developed a system that's claimed to serve that very purpose, for use by firefighters and other rescue workers.
The technology is being developed at the Karlsruhe Institute of Technology, by a team led by Nikolai Kronenwett and retired professor Gert Trommer. It incorporates a wearable device measuring just a few centimeters in size, that's mounted on the user's boot.
As that person is about to enter a building, the system notes their location via GPS. Unfortunately GPS doesn't work reliably indoors, however, which is where the wearable comes in. It takes over once the user goes into the structure, tracking the direction and distance that they travel from their last-known GPS coordinates.
The device does so utilizing an accelerometer and gyroscope that measure the wearer's speed and orientation. That said, its accuracy is boosted by its ability to break down each of the user's strides into the point at which their rear foot rolls off the ground, its subsequent swing forward, and then its re-contact with the ground in front.
All of that data is wirelessly transmitted in real time to a computer located at a command station outside the building. If one of the workers fails to come out of the structure on time, or if it's noted that they've remained immobile for too long, other rescue personnel will thus know where to find them.
The scientists are also working on a separate wrist-worn device, to be used along with the boot-mounted unit. It utilizes an infrared camera to create 3D models of the user's surroundings, providing supervisors with a better idea of what's going on inside the building.