3 ms·

Yes, but how will it determine its position without a reference, I read the article and missed that concept.

saboot 5y ago
I'm also confused by this, does it get set a reference point once? If so what is the accuracy degradation, is it fixed over time or acceleration? If it's updated periodically what does that system look like? Is the advantage that it can manage on its own "offline" for a usable period, unlike GPS which needs an active connection?
- mynegation 5y ago
  All great questions, but I suspect the answers are classified.
- saboot 5y ago
  Here's the press release from Sandia https://www.sandia.gov/labnews/2021/10/22/this-device-could-usher-in-gps-free-navigation/ https://www.sandia.gov/labnews/2021/10/22/this-device-could-... And the published paper it refers to https://avs.scitation.org/doi/10.1116/5.0053885 https://avs.scitation.org/doi/10.1116/5.0053885 And I agree that the answers to my questions are probably not public, this is likely going to be very useful for things that go boom, in addition to a lot of other civilian applications.
throwawaylinux 5y ago
The reference is your previous position. This is known as dead reckoning.
Snoozus 5y ago
Just like dead reckoning works today, you start from a known point at known attitude and integrate up accelerations and rotations to keep an up to date position. Whenever you can get a GPS signal you use that to reduce the drift. Cheap systems can do this for seconds, 10k$ buys you 15minutes (MEMS), 100k an hour (laser gyro), everything above is under export restrictions and NDAs so noone will tell you what the state of the art is. Looks like with these frozen gasses one can build even better sensors, which will make no difference for civilian use because it will be even more expensive than existing systems and also because we wouldn't be allowed to use it.
- jonplackett 5y ago
  The whole premise that this might be something in everyday use one day seems completely flawed. Even at the 1cm cube of physics it’s huge compared to GPS and it uses incredibly expensive materials. If you’re a nuclear submarine or stealth bomber it makes loads of sense. For anything else I don’t really get the point.
  - dogma1138 5y ago
    I recon that’s what said about solid state gyros and accelerometers, vibrating structure gyros were initially developed for the military now they are like a $1 a pop… If this works I can’t see a reason why in 10-15 year you won’t be able to fit it on a single chip.
  - kadoban 5y ago
    If you're anything to do with military, I bet you _really_ badly want this over GPS. GPS can be spoofed or blocked over an area. So every drone, every group of soldiers, every truck, every boat really needs one. Even just as a person, having a nav system that doesn't need to sync before it can be used would be nice, and no possible issues with buildings, trees, hills, etc.
  - soneil 5y ago
    There's a fairly obvious application in pretty much any military theatre. GPS is vulnerable to spoofing, having a second source of truth lets you know you're even being attacked. Comparing an IDS to a GPS at least gives you a canary.
pdonis 5y ago
> how will it determine its position without a reference It won't. It needs a starting position from an external source, and without periodic updates from some external source, errors will build up in this system just as with any inertial navigation system. As I understand it, this system is just supposed to build up errors much more slowly than existing inertial navigation systems, so it can go longer between updates from an external source before its error becomes too large to be acceptable.

I'm also confused by this, does it get set a reference point once? If so what is the accuracy degradation, is it fixed over time or acceleration? If it's updated periodically what does that system look like? Is the advantage that it can manage on its own "offline" for a usable period, unlike GPS which needs an active connection?

mynegation 5y ago
All great questions, but I suspect the answers are classified.
saboot 5y ago
Here's the press release from Sandia https://www.sandia.gov/labnews/2021/10/22/this-device-could-usher-in-gps-free-navigation/ https://www.sandia.gov/labnews/2021/10/22/this-device-could-... And the published paper it refers to https://avs.scitation.org/doi/10.1116/5.0053885 https://avs.scitation.org/doi/10.1116/5.0053885 And I agree that the answers to my questions are probably not public, this is likely going to be very useful for things that go boom, in addition to a lot of other civilian applications.

throwawaylinux 5y ago

The reference is your previous position. This is known as dead reckoning.

Snoozus 5y ago

Just like dead reckoning works today, you start from a known point at known attitude and integrate up accelerations and rotations to keep an up to date position. Whenever you can get a GPS signal you use that to reduce the drift. Cheap systems can do this for seconds, 10k$ buys you 15minutes (MEMS), 100k an hour (laser gyro), everything above is under export restrictions and NDAs so noone will tell you what the state of the art is. Looks like with these frozen gasses one can build even better sensors, which will make no difference for civilian use because it will be even more expensive than existing systems and also because we wouldn't be allowed to use it.

jonplackett 5y ago
The whole premise that this might be something in everyday use one day seems completely flawed. Even at the 1cm cube of physics it’s huge compared to GPS and it uses incredibly expensive materials. If you’re a nuclear submarine or stealth bomber it makes loads of sense. For anything else I don’t really get the point.
- dogma1138 5y ago
  I recon that’s what said about solid state gyros and accelerometers, vibrating structure gyros were initially developed for the military now they are like a $1 a pop… If this works I can’t see a reason why in 10-15 year you won’t be able to fit it on a single chip.
- kadoban 5y ago
  If you're anything to do with military, I bet you _really_ badly want this over GPS. GPS can be spoofed or blocked over an area. So every drone, every group of soldiers, every truck, every boat really needs one. Even just as a person, having a nav system that doesn't need to sync before it can be used would be nice, and no possible issues with buildings, trees, hills, etc.
- soneil 5y ago
  There's a fairly obvious application in pretty much any military theatre. GPS is vulnerable to spoofing, having a second source of truth lets you know you're even being attacked. Comparing an IDS to a GPS at least gives you a canary.

pdonis 5y ago

> how will it determine its position without a reference It won't. It needs a starting position from an external source, and without periodic updates from some external source, errors will build up in this system just as with any inertial navigation system. As I understand it, this system is just supposed to build up errors much more slowly than existing inertial navigation systems, so it can go longer between updates from an external source before its error becomes too large to be acceptable.