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Royal Navy says quantum navigation test a success

thequantuminsider.com

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Re: Royal Navy says quantum navigation test a success

#211

Post by stealthcorp »

jchallis wrote: post #13

This is the most obvious practical application of my PhD topic. A Bose Einstein Condensate is an extremely sensitive detector of gravity- a nuclear submarine could use it to make an ultra-accurate map of the world based on variations in the gravitational constant g. This would remove one of the primary reasons subs need to surface , in order to GPS lock. It’s a naval chart that would not require surfacing. A French p…

Very interesting! What year did you complete your PhD? Care to share a link to your thesis?

Re: Royal Navy says quantum navigation test a success

#212

Post by earthscienceman »

djyaz1200 wrote: post #200
rtkwe wrote: post #189

Earlier quoted context omitted.

It'd be interesting to see if they're sensitive enough to do the opposite detect the gravity anomaly that is the sub. There's a couple near future submarine warfare books where that's one of the devices used to attempt to find subs.

I suspect that may be what these satellites are doing... https://en.wikipedia.org/wiki/GRACE_and_GRACE-FO#:~:text=As%... .

I love when HN commenters get out of water on topics. The GRACE retreivals to reconstruct mass changes for "mascons" that are several hundred kilometers in width\height take a month of static overpasses and incredible mathematics and signal processing. There is absolutely no way that their data could be used to locate a submarines, ever.

Re: Royal Navy says quantum navigation test a success

#213

Post by gitfan86 »

djyaz1200 wrote: post #200
rtkwe wrote: post #189

Earlier quoted context omitted.

It'd be interesting to see if they're sensitive enough to do the opposite detect the gravity anomaly that is the sub. There's a couple near future submarine warfare books where that's one of the devices used to attempt to find subs.

I suspect that may be what these satellites are doing... https://en.wikipedia.org/wiki/GRACE_and_GRACE-FO#:~:text=As%... .

Interesting, seems hard to zero out the clouds and air density, and bodies of water

Re: Royal Navy says quantum navigation test a success

#214

Post by rogers18445 »

jchallis wrote: post #60
rogers18445 wrote: post #29

Earlier quoted context omitted.

What would you do with the g measurement to get your location? Can g deltas be matched to sea floor contour maps? Otherwise it seems like subs would have to be following g-mapped routes.

A typical sub drifts by only a few tens of meters per day - obviously this builds up . The point of the BEC gravity map is to reduce this inaccuracy an order of magnitude, thereby extending the subsurface range of the subs.

But how would you do this? Sensor fusion with inertial sensors is well understood, how do you fuse g into the equation to improve things?

Re: Royal Navy says quantum navigation test a success

#215

Post by rtkwe »

RationPhantoms wrote: post #203
rtkwe wrote: post #190

Earlier quoted context omitted.

Yes it does but we also have satellites mapping those shifts so it could be accounted for. The big question is are those fine grained enough to resolve the errors in modern INSs.

Wouldn't that then require communication with those satellites to receive the shift/drift info? Doesn't that eradicate the point of a navigational system without reliance on GPS/satellites? Or is the drift is so minor that this quantum navigation system can operate for up to 6 months without sufficient core drift alignment calculation?

No idea but there are low bitrate coms available to submarines that could update that data maybe. The changes should be pretty slow at the bulk scale.

Re: Royal Navy says quantum navigation test a success

#216

Post by _Microft »

westurner wrote: post #208
samus wrote: post #137

Earlier quoted context omitted.

Not a formal definition, but noise is simply the undesirable parts of the output of any information processing device, be it a sensor, an amplifier, or a transmission medium. But on Earth it's simply not practical as such. Gravitational waves observatories are used to detect events such as neutron star or black hole mergers that are otherwise unobservable, but they require an insane level of precision to be detected.

Are there yet any instruments better than LIGO at a lagrangian point outside Earth's atmosphere and the Van Allen radiation belt?

No, there’s nothing yet. I think you‘re thinking about (e)LISA btw.

Re: Royal Navy says quantum navigation test a success

#217

Post by WastingMyTime89 »

wslh wrote: post #181
yodon wrote: post #164

Earlier quoted context omitted.

> Is it difficult to build this thing? Yes. > What would a startup need to make this work as a business? Extensive contacts in the submarine navigation ecosystem and several decades of deep knowledge of highly complex, highly classified, related navigation systems that this product would need to interoperate with. This tech is not a magic locator machine on its own, it's a component that improves one small but import…

Thank you, two more questions: do we expect that other governments in the world will build a similar system soon? and/or how many years of advantage does the Royal Navy have?

Nobody knows what the Royal Navy actually has. Nobody knows what other governments have. You are in the realm of what are the actual capabilities of nuclear weapons carrying subs. You can safely assume than anything remotely interesting is classified.

Re: Royal Navy says quantum navigation test a success

#218

Post by mpnordland »

politician wrote: post #178

"The XV Patrick Blackett, the Navy’s new experimental vessel, provided the setting for the experiment. Sky News said the ship makes a perfect host for the futuristic experiment — it boasts a sleek design, featuring tinted windows and a glossy black hull." Aesthetics are key for quantum navigation /s

What's the point of knowing where you are if you don't look cool while you're there? /s On the other hand, I do appreciate the efficiency of serving the PR mission and the testing mission with the same boat.

Re: Royal Navy says quantum navigation test a success

#220

Post by jedc »

jchallis wrote: post #13

This is the most obvious practical application of my PhD topic. A Bose Einstein Condensate is an extremely sensitive detector of gravity- a nuclear submarine could use it to make an ultra-accurate map of the world based on variations in the gravitational constant g. This would remove one of the primary reasons subs need to surface , in order to GPS lock. It’s a naval chart that would not require surfacing. A French p…

Former submariner here with a quibble on this:

> one of the primary reasons subs need to surface , in order to GPS lock

While getting a GPS position is helpful, the primary reason a submarine goes to periscope depth regularly is for communications. The Navy needs to send information to submarines and know that they'll get it and take action within a certain timeframe. That's by far the primary driver.

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