The Navy is testing a GPS-like device that doesn’t require satellites | Hacker News Reader

The Navy is testing a GPS-like device that doesn’t require satellites

taskandpurpose.com

29 pointsdocdeek11 comments

Even if you build a 100% efficient muon detector, how does that give you location? The article hints at timing information as a source of location, but cosmic rays are random, and the best they are going to do is give you an idea of where UP is, which is already easy to determine.

If you have land based detectors, and try to triangulate timings based on bursts, you have to precisely time those bursts, and somehow communicate that information to the submarines.

Otherwise, you're suggesting sending out muon streams from beacons in a manner similar to VOR beacons for air navigation. (I could make that work!)

The paper referenced in the article explains the positioning and reference mechanics. In short, it’s very similar to precise positioning using GNSS (with fixed base reference stations broadcasting corrections to field receivers), but using celestial signal sources along with GNSS averaged positioning data. It’s a really clever use of a natural phenomenon for precise positioning, and somewhat exciting between this for underwater use and pulsars for space positioning.

Riffing, I’d be curious if the surface reference detectors/stations could use pulsars alone for positioning, slowly removing the need for human infra in the positioning network. It seems we’re awash in signal sources, and the work is in intelligent use of them.

https://www.nature.com/articles/s41598-020-75843-7

https://www.nature.com/articles/s41598-020-75843-7/figures/1

Thanks for the reference. I don't see a way this without buoys and detectors spread all over the ocean, somehow transmitting timing information for observed bursts to the submarines. This would make the buoys the first target to "accidentally" destroy (or somehow spoof) prior the beginning of hostilities in a war.

Communication buoys are a well known technology and very cheap ($1k-$2k) in the grand scheme of defense spending. I’d imagine they’d be considered disposable and deployable from air, sea, and underwater. GNSS chipsets can get a lock in under a minute (sub 5-15 seconds with a recent almanac as soon as the sky is visible), so the constraint is how fast they can parse the muon field and how long corrections need to be provided for (perhaps only long enough to provide an INS update [1]?).

[1] https://newsreleases.sandia.gov/quantum_navigation/

If anyone else was intrigued by the passing mention of 'quantum navigation' at the end, here is an article;

https://www.defenseone.com/technology/2021/11/quantum-sensor...

It sounds like this system still needs a conventional communication channel between the receiver and a set of reference stations, right? So it'd be of limited use on a submerged submarine (though you could reconstruct your path post-facto after surfacing I guess ... actually, thinking about it, that alone is probably super useful for mapping and intelligence.)

My memory is fading on this, but I recall that early cruise missiles used some kind of on-board terrain navigation system.

Tomahwaks. They still do. During the Irak war, they had to send them to Baghdad thru a longer path because the desert is so flat and the missile could get lost.

We already had a system that didn't need satellites, it was deemed redundant and shut down.

The headline is deceiving. They are building a system that works where gps is weak; underwater, underground, and at the poles.

The lack of satélites is kind of irrelevant. They are designing a system that doesn’t use radio waves, which IS totally different to older systems.

yep. pretty sure a vectornav gives decent resolution using magnetic model of the earth, although not gps rez.

https://www.vectornav.com

Reply on news.ycombinator.com