The global positioning system can locate you within 5 to 10 meters anywhere on Earth—as long as your receiver is in the line of sight of multiple satellites.
The navigation system, installed in a very hefty prototype boot, could help rescue workers navigate inside buildings, and show firefighters where their team members are.
The Utah group’s navigation system is built on an inertial measurement unit or IMU—a little black box containing a gyroscope, magnetometer, and accelerometer.
High-end systems of this kind help airplane pilots navigate.
Darrin Young, an electrical engineer at the University of Utah, wanted to make it possible to use an IMU in portable electronics.
But readings from cheap versions of these sensors drift over time, and errors can accumulate rapidly.