Scientists conduct first test of a wireless cosmic ray navigation system

It does address clock distribution, though the distribution method is sneakernet, in other words "synchronise clocks at one location, then walk away and come back with it".

Yes, it's the same muon leaving a signal in the reference detector as in the mobile platform. Their example applications of guiding robots underground all allow for instrumenting the surface. It's not for navigating in the open ocean, but it could be an upgrade over radio based methods of guiding directional drilling heads and things like that.

The trick is, it's all the same muon!

https://en.m.wikipedia.org/wiki/One-electron_universe

Having not read the article, nor really the Ars piece either, let me hand wave by saying that cosmic muons are produced as secondary particles emitted from a high energy collision of a primary extraterrestrial particle that collides with particles in the stratosphere (around 30km up). This shower of muons is “boosted” by kinetic energy of the primary particle. That means they have a lifetime that is longer than at rest when observed from Earth, but relevant to this method, they are also temporally correlated in such a way that by determining the time of arrival at multiple stations, the origin of the primary interaction can be determined - and more importantly, the timings between the stations can be deduced. Having fixed stations, and an unfixed one, means you can infer the latter’s position through geometric analysis.

Yeah, for some reason the Ars write-up is honouring the very poor explanations in the papers they reference...

Late update: I'm now convinced it's a single-muon thing, because of the paper's discussion about the distance between, and *solid angle* subtended by, the two detectors (eq. 2). If they go too far apart, the rate of individual muons that coincidentally hit both detectors drops to unusably low levels (eq. 3, the 1/D² dependence). If it were instead a "they're detecting secondary particles from the same cosmic shower" like someone proposed, this part would be totally different.

Looks like they're different. OP is using muons (Cosmic rays) and the Royal Navy one is using some quantic properties to track movements more precisely (fancier dead reckoning)

The Royal Navy’s system uses a Bose Einstein condensate as a part of an IMU. This system is referencing muons passing through.

No

Not at all. This solves a somewhat different problem: determining your position relative to a number of nearby reference stations (on the order of tens of meters away).

The limiting factor is that you have to wait for enough muons to pass through both your mobile detector and your reference stations. The farther apart they are, the lower the odds of this happening by random chance, so the longer you have to wait, with the fix time increasing proportional to distance^2. You also need a very accurate shared time reference between the reference detectors and the receiver; for this experiment, that was provided by piggybacking on GPS time.

The detector also needs to be fairly physically large. The Ars Technica article talks about the potential for miniaturization, but I believe this is a distortion or misunderstanding of the research. It's true that the researchers anticipate being able to miniaturize and improve some of the electronics of the detector, primarily through the use of chip-scale atomic clocks rather than OCXOs. But as the paper discusses (pg. 13), you can't really miniaturize the muon detector itself; it needs to be physically large because the muon detection rate is directly proportional to its area. For this experiment, 100x100x2 cm plastic scintillators were used.

As far as I can tell, this technique relies on post-processing of data from the separated detectors, so it isn’t a realtime system.