Global Position Without Satellites

The prototype timing and inertial measurement unit chip has the capabilities of GPS without using global positioning satellites. The chip is about a third the width of a penny and said to be the thickness of six human hairs.

There are fears, particularly in the military, of an over-reliance on global positioning satellites. Those concerns were manifested recently when North Korea scrambled GPS signals in South Korea.

To address the vulnerabilities of GPS, researchers at the Defense Advanced Research Projects Agency (DARPA) and the University of Michigan have created a new position, time and direction system in the form of an eight-cubic-millimeter chip. The tiny chip, called a "timing and inertial measurement unit" (TIMU), houses three gyroscopes, three accelerometers and an atomic clock that work together as an autonomous navigation system.