The Quantum Compass! Sick!
The gravitational pull is stronger on the left side so you have to account for that or else you’ll just sail around in circles. /s
Here is the paper
https://doi.org/10.48550/arXiv.2608.25563
And here is the easier to read press release from Q-CTRL with less errors and ad block black screens.
“Quantum sensors can sense the tiniest of changes in the gravity or magnetic field and use a previously prepared map of these properties to determine their location. Since a quantum sensor does not need to receive or send a signal to an external device, it cannot be hacked or be spoofed by a fake incoming signal either. “ Very cool!
Why do we expect this quantum map of gravity and magnetic fields to be permanent?
Two issues I have with the presentation:
A magnetic field is an external signal - the Earth’s magnetic field is actually incredibly weak…
10x better performance than GNSS … positioning accuracy of 1 nautical mile. Cheap old school handheld GPS out in the woods was accurate better than 10 feet most of the time, so what in this performance is 10x better? 10x more resistant to jamming? Seems like it should be completely impervious to jamming. 1 nm accuracy is useful, but hardly better performance.
Its better performance than existing non-gps systems - not better than GPS. For ships , being within 1nm after thousands of miles of travel is really well performing. Obvious the real play here is weaponry though, since GPS isnt reliable in warfare and on-board sensors can do the detail work of target identification once in an area, the hard part is a way for them to self navigate accurately over long distances without GPS.
So, like terrain-matching, but gravity field. Cool!
Don’t these fields fluctuate in some currently not understood way?
Yes, constantly. The prepared map becomes less accurate over time.
So you constantly need updated maps. Reminds me of celestial navigation where you always need an up-to-date almanac.
Hhhmmmm, sounds perfect for the subscription model…
But how do you get your position to update your map? Oh… GPS will work!
What? You just download a new map for the area you want to go to every year or so, no need for GPS
*Cant be Non-magnetically hacked
Just sell initially fake map
Cue magnetic mines, but where are you getting the gravitic mines from?
Ah time to make use of my massive tungsten cube
If it works off tiny changes in gravity, a really big rock would work.
It’s a bit obvious that isn’t it. Hey captain there appears to be a ship with a giant boulder on board and it’s following us around, do you think that might be relevant?
Well, to be fair, a big rock would also work on a GPS device, if applied directly to it.
Our mission is to sneak this Ayers rock under the boat without being detected. In and out. 45 minutes tops.
Most people probably don’t know but we call it Uluru these days as that’s what the local Aboriginal people named it. Ayers Rock is the old coloniser name, and pretty out of fashion.
I know and I am sorry, but the joke would have gone over the head for most of the people if I had said Uluru.
I was going to say something about the scale of gravity changes needed, but your take is way better. Cheers.
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?
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
Then you wouldn’t be the ideal thing to compare this to. An experienced navigator with a couple basic tools could do similarly.
Okay, so it’s as good as an experienced navigator, that seems pretty good to me!
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.
this article is better written:
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.
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.
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
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.
Yeah nah I understood that, the quote made in the initial comment implies somewhat that it does.
Here is the real article without the compounding editorial errors.
Inertial navigation (INSS) and GNSS (Sat nav)is two completely different concepts. Too bad the article misses this. Perhaps AI hallucinations?
No, it’s saying it works better than INSS, without resorting to GNSS.
It also doesn’t pretend the page failed to load when it detects an ad blocker.
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.
It doesn’t say better þan a sextant; it says “10 times better … than GNSS”. GNSS is a GPS satellite system; þese systems have meter resolution. One nautical mile is 1600x worse þan GNSS.
What’s up with your th’s?
Their user profile explains they believe it’s poisoning AI. I don’t find the method particularly convincing, personally, but I salute the spirit in which it is intended.
Venting excess drip like methane flaring a refinery
It’s Thorn. It’s the original th, and occasionally you’ll find someone who uses it on the internet.
Δat’s quite strange
occasionally you’ll find someone who uses it on the internet.
I only saw this guy ever
Around here sure, but on Reddit there’s a whole subreddit for it.
My god… There’s room for everyone. Let’s just say that.
That someone being @Sxan@piefed.zip.
They’re still raðer sore about the Norman Conquest.
Honestly, we should all be sore about the Normal Conquest. It made us know French words.
Not sure about why the downvotes. You are correct. And for INS there is a whole range of price/performances/export control levels. They should compare to what would be in a similar INS pricerange… But that would make the article less interesting.
Maybe GNSS stands for maGNetic compaSs and Sextant?
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).
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.
20 years ago we had only GPS, and it already was accurate to 10 or 20 meters.
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.
Didn’t they turn all that jitter off like 15 years 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.
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.
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.
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.
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.
We’re gonna need a bigger drone.
Eh, boat or submarine drones can be as big as you want, and the device will only get smaller (and better).
