this post was submitted on 29 Aug 2026
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[–] Zedstrian@sopuli.xyz 74 points 12 hours ago (6 children)

The team achieved 10 times better performance than GNSS systems, with a one nautical mile of positioning accuracy.

Variation up to a full nautical mile doesn't seem very accurate?

[–] hasnep@lemmy.ml 26 points 8 hours ago (1 children)

If I were in the middle of the ocean I couldn't find my location within 100 nautical miles without GPS so I'm pretty impressed

[–] kbobabob@lemmy.dbzer0.com 3 points 4 hours ago (2 children)

Then you wouldn't be the ideal thing to compare this to. An experienced navigator with a couple basic tools could do similarly.

[–] hasnep@lemmy.ml 5 points 2 hours ago

Okay, so it's as good as an experienced navigator, that seems pretty good to me!

[–] echodot@feddit.uk 3 points 2 hours ago

Experience navigators with some basic tools often ended up hundreds and hundreds of miles off course because they had no reference points. If you're navigation system is landmarks plus a sextant then it's not going to be very accurate.

When you're trying to transit the ocean one nautical miles worth of accuracy isn't bad, especially if the alternative is to use a potentially compromised GPS or a 15th century navigation tool.

[–] Gsus4@mander.xyz 128 points 12 hours ago (4 children)

this article is better written:

https://science.report/discover/quantum-gravimeter-demonstrates-gps-free-navigation-in-coral-sea-trial-86654/

it maintained bounded position accuracy within 1 nautical mile over an 83-kilometer trajectory. This performance, achieved without access to satellite navigation, represents a more than tenfold improvement over standard navigation-grade inertial backup systems under similar conditions.

[–] stylusmobilus@aussie.zone 6 points 6 hours ago (1 children)

That’s better, thank you

As a holder of a spatial degree I found it difficult to directly compare it favourably to GNSS. Even a simple binary code calculating a position with GNSS gives sub 10-20 metre accuracy, generally closer to 2 or 3.

[–] Kushan@lemmy.world 11 points 5 hours ago (2 children)

I don't think it's meant to be better than GNSS in terms of accuracy, just better in terms of reliability because it works entirely standalone without a need for satellite

[–] UnityDevice@lemmy.zip 3 points 4 hours ago* (last edited 4 hours ago)

There have been lots of cases of GPS jamming lately, where this could be used as a backup. And even more crucial for certain situations, it could detect GPS spoofing attacks.

[–] stylusmobilus@aussie.zone 1 points 5 hours ago

Yeah nah I understood that, the quote made in the initial comment implies somewhat that it does.

[–] Dimand@aussie.zone 22 points 8 hours ago

Here is the real article without the compounding editorial errors.

https://doi.org/10.48550/arXiv.2608.25563

[–] SatanClaws@lemmy.world 11 points 8 hours ago (1 children)

Inertial navigation (INSS) and GNSS (Sat nav)is two completely different concepts. Too bad the article misses this. Perhaps AI hallucinations?

[–] Aqarius@lemmy.world 1 points 3 hours ago

No, it's saying it works better than INSS, without resorting to GNSS.

[–] Deebster@infosec.pub 50 points 12 hours ago

It also doesn't pretend the page failed to load when it detects an ad blocker.

[–] cmnybo@discuss.tchncs.de 31 points 11 hours ago (1 children)

That's comparable to what a skilled navigator can do with a sextant and chronometer. That's more than enough accuracy to cross the ocean and get close enough to the port that you can see it.

[–] schipelblorp@sh.itjust.works 16 points 12 hours ago* (last edited 11 hours ago)

Maybe GNSS stands for maGNetic compaSs and Sextant?

[–] Deebster@infosec.pub 5 points 12 hours ago (2 children)

The only thing I can think is that they're comparing with a single system (e.g. GPS or BeiDou), even though GNSS receivers will combine all four systems to get very high accuracy (a few metres).

[–] Dimand@aussie.zone 9 points 8 hours ago

They are comparing purely inertial navigation (I assume using the advanced nav boreas D90) and inertial nav combined with gravity map matching.

It is more of a demonstration than a comparison. Pure inertial nav has no way to re zero from an external reference so the error only grows.

Both of these systems are worse than any form of sat nav. But both of them keep working if the sat nav is jammed.

https://doi.org/10.48550/arXiv.2608.25563

[–] elmicha@feddit.org 9 points 12 hours ago (2 children)

20 years ago we had only GPS, and it already was accurate to 10 or 20 meters.

[–] zqps@sh.itjust.works 15 points 10 hours ago* (last edited 10 hours ago) (1 children)

GPS is actually far more accurate than that. There is deterministic jitter introduced to make civilian use cases precise to only a few meters, but military equipment has the algorithm to subtract that jitter and achieve precision measured in centimeters.

Anyway, that statement is highly misleading. They were comparing to previous inertial navigation systems, not GPS navigation.

[–] logi@lemmy.world 9 points 9 hours ago

Didn't they turn all that jitter off like 15 years ago?

[–] Deebster@infosec.pub 7 points 11 hours ago* (last edited 11 hours ago)

Is that true globally? I seem to remember that some ocean areas wouldn't have as many satellites visible as e.g. polar orbits don't visit all of the globe.

[–] Gsus4@mander.xyz 4 points 12 hours ago (1 children)

Yeah, I agree that I didnt understand that bit. I also didn't understand why you need a quantum sensor to follow a map of gravitational and magnetic anomalies for orientation.

[–] Dimand@aussie.zone 7 points 8 hours ago (1 children)

You don't. Any appropriately sensitive/accurate accelerometer or magnetometer is sufficient to do this.

The quantum part is 90% hype used to and attract funding. There are some advantages to the cold atom based sensors Q-CTRL makes, along with issues that need to be worked on, but they are other sensing technologies that could beat it in the long run.

[–] SmoothOperator@lemmy.world 6 points 6 hours ago (1 children)

You don't. Any appropriately sensitive/accurate accelerometer or magnetometer is sufficient to do this.

There are limits to sensitivity and accuracy that can only be overcome by quantum sensing though. So yes, you're right, but that's actually the point of the quantum part.

[–] Dimand@aussie.zone 2 points 6 hours ago

This is a rather common misconception about sensitivity, it is only true under the constraint where you are unable to increase the amplitude of your measurement.

You are always limited by shot noise (counting noise, quantisation noise, Poisson noise, whatever name you give it). And people love to say that you can only beat it by squeezing (increase noise in one quadrature to reduce it in another). But another option is to just increase N, turn up the laser power to have more photons or atoms in your sensor and watch your noise floor drop way faster than you will ever get using squeezing.

Now the cold atom sensors are an interesting case. No one has managed to laser cool atoms faster than an overall rate of around 10^9 atoms per second. And we have been stuck there since the mid 2000s. As a result, the fundamental noise limit from shot noise hampers these cold atom accelerometers significantly in short term sensitivity, as they just don't have enough N of atoms in free fall. In this case, you might look to squeeze to get a better signal, but that's a lot of complexity for not much gain.

There are only 2 examples I know of where squeezing has made a difference to a real world measurement. LIGO, can't increase photons without thermally heating the mirrors too much, and confocal microscopes looking at biological samples, cant turn up the laser power without burning the tissue. In 99% of cases, just increase N to make a better sensor.