When it comes to precision sensing, secure battlefield communications, and global positioning systems, DARPA knows what time it is. However, a lack of coordinated clocks is a hindrance on the battlefield and elsewhere. That's why DARPA has put its feelers out for technology that could lead to portable atomic clocks that are miniature, ruggedized versions of the massive devices that keep standardized time in laboratories around the world.
DARPA's Quantum Assisted Sensing and Readout (QuASAR) program aims to take high-performance atomic clocks like the National Institute of Standards and Technology's NIST-F1, the massive room-sized clock housed in a lab in Boulder, Colo. Doing so won't be any easier than many other challenges DARPA brings to the table, but the agency thinks advances in nanoelectromechanical systems (NEMS) resonators and nitrogen-vacancy (NV) centers in diamonds that exhibit single-atom-like properties could create a close analog to an atomic clock in a miniature, portable package.
Atomic clocks don't lose seconds or even fractions of seconds over time (well, that's not entirely true, but time lost is negligible; NIST-F1 will neither gain nor lose a second in 60 million years), and that opens up major possibilities for syncronisity. Such portable clocks would allow for communications systems that are far more secure less susceptible to jamming and GPS positioning that is unrivaled. DARPA also thinks they might lead to precision sensors unrivaled in resolution and sensitivity.
Could Also make GPS controlled cars with this I think.
The NIST clock is available through WWV, at least it has been. I think that there is pretty much worldwide coverage, but I could be wrong.
I would think that most of these issues could be solved using time sync'd to WWV. Yes, it's an RF timestamp, but one that probably isn't normally blocked.
GPS sats also supply super accurate time, although GPS does seen to be a target for electronic attacks.
If I'm not mistaken, minor distance lag and time dilation takes place between satellites and surface based systems. They work fine for getting your car to a Starbucks, but not so much for precision instruments.
Probably someone could be working on a "prototype" model as we speak because this atomic watch/clock would be an important app to add to a smart phone. I believe many people if not most people look up time on their mobile phones. (may be Android apps developers could be working on it, so they could coordinate with the designers).