The next generation of atomic clocks might one day help drive your car.

Remotely operated vehicles remain a futuristic idea, but researchers led by a team at the National Institute of Standards and Technology and the University of Colorado have created prototypes of a pair of atomic clocks that could improve the precision of such technologies as a Global Positioning System.

"Right now, GPS is good enough for a few tenths of a meter," project leader Andrew Ludlow said. "But obviously that's not good enough to keep two cars from colliding."

Atomic clocks are critical elements of every GPS satellite. Satellites interact via radio signals with local receivers, like smartphones or navigation devices.

"The satellite sends a signal down that says exactly what time it is. It takes time for the signal to travel to the local receiver," Ludlow said. "You can do some math and figure out where a local receiver is located."

The researchers have found a way to speed the time an atomic clock needs to achieve what is considered precision timekeeping, opening doors for applications such as GPS to run more accurately in real time.

The research findings were published Thursday in the journal Science Express.

Although they are considered the most accurate timekeeping devices on the planet, atomic clocks do not produce "ticks" of exactly the same length. To improve performance, their measurements are averaged over time to produce stable ticks. The new-model atomic clocks can achieve the stability in one second that an older model needed five days to achieve.


The new clocks achieve the time saving by using about 10,000 atoms of the rare-earth element ytterbium, cooled to 10 millionths of a degree above absolute zero, instead of cesium, which is used by many of the last generation of atomic clocks.

Although the ytterbium-clock ticks are 10 times more stable than the best published results of other atomic clocks, Ludlow insists that his new clock should not be described as more accurate.

"We are just adding one ingredient, which is stability," he said.

Whether the greater stability can be reproduced under differing circumstances will prove whether the clocks are a superior method of measuring time, he said.

Katharina Buchholz: 303-954-1753, kbuchholz@