Reading the article, it seems the real use case (unmentioned) is on ballistic missile nuclear subs.

You want them to be well below the surface of the water, where the GPS signal does not penetrate so well. Thus having a way for them to know precisely where they are without relying on GPS would be very helpful.

So now they can run Red Route One at high speed. All they need now is to "Engadge je shilent drife"

Neat. Geopositioning in general is a "hard problem" especially with additional variables/complexities that are introduced for specific use cases (military or not). There's tons of room for cutting edge research here still, and it's exciting to see companies invest in that.

Very interesting, and amazing technology. But… How is it unjammable? Couldn’t you just generate a big magnetic field?

Magnetic field drops off by an inverse-cubed law (as opposed to inverse-squared for RF). So it would be a lot more impractical to cover large volumes.

Thanks. I would still be curious to know how the strength of an artificial magnetic field at a range of say 10 km compares to the order of magnitude of local variations they are talking about in the earth’s magnetic field.

Make some assumptions, find the relevant equations, and plug in the numbers.

https://en.wikipedia.org/wiki/Magnetic_field

IIRC I think there was a telephone system with giant magnetic coils that went a quarter mile, but maybe I read a blog wrong or something.

In any case it wouldn't be as portable and would make you rather easy to detect I would imagine, if you wanted to cover a large area.

This looks like it might be in a similar vein to the navigation system discussed in a previous post about a new Royal navy test system. There are many good links in the comments https://news.ycombinator.com/item?id=36222625

They also have made a very large and high tech scraping knife, to remove any jam.

/Jk

Raspberry!

Oh yes https://movie-sounds.org/sci-fi-movie-samples/quotes-with-so...

(2019)