Quantum alternative to GPS navigation will be tested on US military spaceplane
The experimental sensor could be groundbreaking.
cross-posted from: https://programming.dev/post/35701350
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This sounds pretty fancy.
Commercial aircraft get their location from multiple places including GPS, ground based facilities (VOR's), IRS, etc. IRS is what I'm used to calling it, but it's the same as INS, which is what this article is talking about.
It determines location by keeping track of rotation, acceleration, etc. It's often called "dead reckoning" because it just gives the best guess, and you don't know how accurate it is. There are multiple of these devices on each aircraft, and they compare their locations to the other sources and if one is drifting way further than the rest, it gets ignored. That's a very basic explanation because how it really works is way above my knowledge level.
It's very cool how these devices find their location, though. When you first boot the system up, it spends about 5 minutes measuring the rotation of the Earth. For this reason, you can't reset it when in motion. Based on what it feels it can determine your exact location on the surface of the earth.
To be clear, what you're describing is only true of INS. Other methods do not have these limitations, like GPS constantly receives the satellite signal to place your position.
The article is about a highly accurate (orders of magnitude) INS system.
When you first boot the system up, it spends about 5 minutes measuring the rotation of the Earth. For this reason, you can't reset it when in motion.
That's very interesting. I've heard a lot about IRS/INS, but I didn't know what it was doing during initialization.
It must be an extremely sensitive instrument if it can measure the rotation of the Earth. I'm wondering, does anyone in the cockpit have to sit still when it boots up? Because I can imagine walking around in the plane alone, or even just a powerful sneeze would already introduce some movement, not to talk about the ground handlers loading the cargo.
It's recommended to not begin boarding until it's finished, but one person moving around, gusts of wind, etc. don't bother it.
So it figures out where you are based on vibes?
It's very cool how these devices find their location, though. When you first boot the system up, it spends about 5 minutes measuring the rotation of the Earth. For this reason, you can't reset it when in motion. Based on what it feels it can determine your exact location on the surface of the earth.
That gets you longitude but not latitude, right?
I've been trying to think through how it would determine longitude based on rotation of the earth and I agree, that's not really possible. I wonder what other tricks it uses to find the initial location.
I don’t know how it does it but earth rotation speed will be different at different latitudes and elevations. Theoretically, a device sensitive enough might be able to determine precise location from just rotation speed and a very accurate geoid.
Hmmm so in the future we will have AI best guessing planes locations? Ye haw.
I doubt it'll ever be used on commercial aircraft, since they do have GPS and all the other things there isn't really any point adding a yet another system. Especially because it requires cooling, if it gets too warm it stops working, and buy too warm I mean the temperature of interplanetary space is too warm. Basically has to be absolute zero or bust.
Who knows.
Special relativity was a niche branch of interest until we needed to correct for time signal differences between moving satellites. Quantum mechanical understanding of electrons was a weird quirk of math until they used electron buckets to make SSDs.
Publically funded general research leads to unexpected uses.
