DARPA has announced the Robust Optical Clock Network (ROCkN) program, which aims to create optical atomic clocks with low size, weight, and power (SWaP) that yield timing accuracy and holdover better than GPS atomic clocks and can be used outside a laboratory. This will mean planes, ships, missiles and other military hardware will carry devices for ultraprecise time which gives ultraprecise position that cannot be jammed.

If successful, these optical clocks would provide a 100x increase in precision, or decrease in timing error, over existing microwave atomic clocks, and demonstrate improved holdover of nanosecond timing precision from a few hours to a month. This program could create many of the critical technologies, components, and demonstrations leading to a potential future networked clock architecture.

In the first round the goal is to design a portable optical atomic clock that could fit on a fighter jet or satellite providing picosecond (trillionth of a second) accuracy for 100 seconds. The clock will need to withstand temperature, acceleration, and vibrational noise for use on board aircraft, vehicles, or satellites.

The second technical area calls for performers to develop an optical atomic clock in a transportable package that could fit on a Navy ship or in a field tent to provide GPS-equivalent, nanosecond precision for 30 days in the absence of GPS.