So far as I can tell, it's this accelerometer: https://www.imperial.ac.uk/news/188973/quantum-compass-could...
(2018, I'm unclear what's changed since then?)
London Underground hosts tests for 'quantum compass' that could replace GPS
11–20 of 146 posts
Re: London Underground hosts tests for 'quantum compass' that could replace GPS
#12Journalists get it wrong, again. Sigh. It will never replace GNSS. It's quantum inertial navigation (QIN) that double-integrates acceleration like another method, requiring external position, heading, and velocity (re)calibration and drifts without them. It has absolutely no idea where it is from only itself.
From the article: "This information, combined with the starting point of that object, allows its future positions to be calculated."
It doesn’t go into the details of recalibration, I’ll give you that.
Re: London Underground hosts tests for 'quantum compass' that could replace GPS
#13Related: South-pointing chariot, 5th century BC
Re: London Underground hosts tests for 'quantum compass' that could replace GPS
#14Journalists get it wrong, again. Sigh. It will never replace GNSS. It's quantum inertial navigation (QIN) that double-integrates acceleration like another method, requiring external position, heading, and velocity (re)calibration and drifts without them. It has absolutely no idea where it is from only itself.
From the article: "This information, combined with the starting point of that object, allows its future positions to be calculated." It doesn’t go into the details of recalibration, I’ll give you that.
Because it can't. There are always cumulative errors in INS. There is no way around this without external references, but then it's no longer inertial navigation and it's inertial-assisted navigation.
An underground navigation system based on triangulation of UWB cells would be a better solution than some nonstarter project the size of a refrigerator that requires liquid nitrogen.
Re: London Underground hosts tests for 'quantum compass' that could replace GPS
#15Journalists get it wrong, again. Sigh. It will never replace GNSS. It's quantum inertial navigation (QIN) that double-integrates acceleration like another method, requiring external position, heading, and velocity (re)calibration and drifts without them. It has absolutely no idea where it is from only itself.
>>> It will never replace GNSS.
It will have to. That is the point. This isn't about better in-car navigation. The big money behind quantum gyroscopes is the potential to guide submarines/aircraft/missiles in times of war when the GNSS systems are down or otherwise unreliable, just like the best of traditional gyroscopes. Dead reckoning is a legitimate means of navigation, but there are also some aspects where actual replacement of GNSS might happen. An extremely sensitive gyroscope could probably determine latitude based on the earth's rotation (Foucault Pendulum). Then layer on a detailed map of variations in the earth's gravity and/or magnetic fields and one might be able to pinpoint a location absent external signals.
https://en.wikipedia.org/wiki/Advanced_Inertial_Reference_Sp...
Re: London Underground hosts tests for 'quantum compass' that could replace GPS
#16Journalists get it wrong, again. Sigh. It will never replace GNSS. It's quantum inertial navigation (QIN) that double-integrates acceleration like another method, requiring external position, heading, and velocity (re)calibration and drifts without them. It has absolutely no idea where it is from only itself.
>>> It will never replace GNSS. It will have to. That is the point. This isn't about better in-car navigation. The big money behind quantum gyroscopes is the potential to guide submarines/aircraft/missiles in times of war when the GNSS systems are down or otherwise unreliable, just like the best of traditional gyroscopes. Dead reckoning is a legitimate means of navigation, but there are also some aspects where actual…
That's an extremely niche application unlikely to be scaled down to anything smaller than a backpack like laser ring gyros. As such, this type of positioning gear isn't for consumer use and is targeted mostly for underground surveying.
(I worked for Trimble.)
Re: London Underground hosts tests for 'quantum compass' that could replace GPS
#17Earlier quoted context omitted.
From the article: "This information, combined with the starting point of that object, allows its future positions to be calculated." It doesn’t go into the details of recalibration, I’ll give you that.
Because it can't. There are always cumulative errors in INS. There is no way around this without external references, but then it's no longer inertial navigation and it's inertial-assisted navigation. An underground navigation system based on triangulation of UWB cells would be a better solution than some nonstarter project the size of a refrigerator that requires liquid nitrogen.
> There are always cumulative errors in INS.
Is that necessarily true of this quantum thing? I know nothing about it except this article, theoretically if it kept track of exact Plank lengths or something, then there would be no errors to accumulate, right? Lots of the things that seem intuitively true break down in weird ways when dealing with quantum effects.
Re: London Underground hosts tests for 'quantum compass' that could replace GPS
#18Earlier quoted context omitted.
>>> It will never replace GNSS. It will have to. That is the point. This isn't about better in-car navigation. The big money behind quantum gyroscopes is the potential to guide submarines/aircraft/missiles in times of war when the GNSS systems are down or otherwise unreliable, just like the best of traditional gyroscopes. Dead reckoning is a legitimate means of navigation, but there are also some aspects where actual…
That's an extremely niche application unlikely to be scaled down to anything smaller than a backpack like laser ring gyros. As such, this type of positioning gear isn't for consumer use and is targeted mostly for underground surveying. (I worked for Trimble.)
...yeah? I don't think anyone has claimed they're developing this for consumer use.
Re: London Underground hosts tests for 'quantum compass' that could replace GPS
#19Journalists get it wrong, again. Sigh. It will never replace GNSS. It's quantum inertial navigation (QIN) that double-integrates acceleration like another method, requiring external position, heading, and velocity (re)calibration and drifts without them. It has absolutely no idea where it is from only itself.
>>> It will never replace GNSS. It will have to. That is the point. This isn't about better in-car navigation. The big money behind quantum gyroscopes is the potential to guide submarines/aircraft/missiles in times of war when the GNSS systems are down or otherwise unreliable, just like the best of traditional gyroscopes. Dead reckoning is a legitimate means of navigation, but there are also some aspects where actual…
Fair point, this would fit quite snugly on a ship or a sub.
the real ones will probably smaller.
I wonder will having more than one improve accuracy.
Re: London Underground hosts tests for 'quantum compass' that could replace GPS
#20So far as I can tell, it's this accelerometer: https://www.imperial.ac.uk/news/188973/quantum-compass-could... (2018, I'm unclear what's changed since then?)
Russia launched a satellite capable of destroying GPS satellites and suddenly funding became available?