Is It Really GPS If It Doesn't Use Satellites?

cartechboy writes: "GPS was originally developed by the military, but today it's in your smartphones, and soon, possibly your watches. Now the British military is developing something called quantum compass. The concept is a GPS-style navigation for submarines that doesn't use satellites. The quantum compass uses the movements of super-cooled subatomic particles to pinpoint a vessel's location. These particles, stored in a vacuum, react to the Earth's magnetic field. The movements caused by this interaction can be used for location positioning. At the moment, the Ministry of Defense's prototype resembles a '1-meter long shoe box,' so the next step is to miniaturize it. It could then be used by individual soldiers, as well as huge ships and submarines. Not only is it useful, but it's secure too—the technology is apparently interference-proof. Is this the future of navigation systems, or the reinvention of the compass? Possibly both."

Comments

Not GPS

[Megane]

Nope.

Sounds like more like an inertial navigation system, but one that uses the Earth's magnetic field instead of just being shaken around.

depends.

[gandhi_2]

Are we saying Global Positioning System, capitalized and considered a Proper Noun?
Then, no.

Are we saying global positionin system, a generalized term for systems that give you position data on the globe?
Then yes.

LORAN, EPLRS (when used as it was actually created for instead of a mesh data network), VORTAC, and probably many other systems were all generic positioning systems.

If the earths magnetic field moves (and it does), then won't this system also be affected?

Re:Does it give you a position on the globe?

[Missing.Matter]

A map is not a system.

Re:Durability?

[Lumpy]

About 3 inches. The GPS satellites transmit signals on two carrier frequencies. The L1 carrier is 1575.42 MHz and carries both the status message and a pseudo-random code for timing. The L2 carrier is 1227.60 MHz and is used for the more precise military data stream

Salt water attenuates 1.5ghz signals quite effectively.

Article is lame blogspam. Here's the real info.

[Animats]

Lame article, which points to a blog, which points to another blog, which points to the wrong place on a Russian site, which copied the article from The Daily Mail. The Daily Mail, even though a tabloid, has a halfway decent article.

I'm not going to explain inertial guidance; that's what Wikipedia is for. This is better inertial guidance. Here's a popular article which describes this new class of "gyros" and accelerometers. If you really want to know what's going on here, read Advances in Atomic Gyroscopes: A View from Inertial Navigation Applications

Laser "gyros", which work by interferometery and have no moving parts, have been around for decades. The best laser gyros still have more drift, by about 2 orders of magnitude, than the best mechanical gyros. Laser gyro technology has hit the limits of what you can do with photons. The idea here is to do interferometry with coupled atoms, rather than photons. That technology has been slowly improving for a decade or so, and it looks like it's getting close to deployment for high-end applcations.

One of the more interesting possibilities here is chip-scale gyros of moderate precision. Here's a Honewell patent from 2006 for one.

Re:stable magnetic field

[The Raven]

This is not a compass. This measures the atoms passing through lines of magnetic flux. The magnetic flux lines are remarkably uniform when you are not within range of a competing magnet; I suspect that is just as true underwater. It's like measuring your distance from the center of a record by counting the track grooves you have scratched over. It does mean it's more accurate at east-west than it is at north-south.