New atomic clock accurately calibrates time for ships with a daily error of less than 300 trillionths of a second

Vector Atomic, a US manufacturer of navigation and communications equipment, has developed a new ultra-precise and rugged atomic clock. In the latest issue of Nature, the team reports on the development and sea testing of the atomic clock, which has performance comparable to the best commercial atomic clocks, but in a much smaller package.

Schematic diagram of the performance of a single clock at sea.
Image source: Nature magazine

As ship instruments become more complex, the technology behind them increasingly relies on precise timing, such as radio positioning systems used for navigation. Such systems measure the propagation of signals between satellites, and very small errors in timing can result in positioning errors of hundreds of meters. When used on warships, this can have serious consequences.

Currently, atomic clocks used on ships are stable enough to cope with the wobbling of ships, but they are not nearly as accurate as those used in research labs. Now, a research team has developed a clock that could bridge that gap.

The clock, based on oscillating iodine molecules, weighs just 26 kilograms, about the size of three shoe boxes, and can be used on almost any ship. The research team says it is about 1,000 times more accurate than the clocks currently used on most ships.

The development team tested the clock on a warship in the Pacific Ocean, using it for three weeks of normal shipping operations. Test data showed that the clock was almost as accurate as when tested in the laboratory, with the time error remaining within 300 trillionths of a second each day.

The demonstration marks a major technological advance that could herald the arrival of future optical timing networks. The development team noted that they are continuing their research and hope to make the clock smaller so that it can be carried by navigation satellites.