Is It Really GPS If It Doesn't Use Satellites? 298
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."
What kind of question is that? (Score:4, Interesting)
Of course it is. It's Global Positioning System, not GLONASS Points South. Doesn't matter how you know where you are, as long as you know where you are with some accuracy. It's unlikely this method will be as accurate as using an actual satellite-based GPS, but probably good enough for submarines that can stay under for months at a time.
stable magnetic field (Score:5, Interesting)
I'm kind of surprised that Earth's magnetic field is stable enough for this to work well. Or if nothing else, wouldn't local magnetic field disturbances goof it up?
Re:How new is this? (Score:2, Interesting)
Sounds like a lot of trouble to create a system that's ultimately inferior to the Ring Laser Gyroscope (which was made for this very purpose).
Re:Man-portable supercooling? (Score:5, Interesting)
The supercooling is apparently done using lasers, so something that is man-portable is maybe realistic
The DSTL's team was inspired by the Nobel-prize winning discovery that revealed that lasers can trap and cool a cloud of atoms placed in a vacuum to less than a millionth of a degree above absolute zero
Re:Does it give you a position on the globe? (Score:2, Interesting)
Vacuum? (Score:4, Interesting)
Re:Durability? (Score:4, Interesting)
Salt water attenuates all radio quite effectively, except for VLF, which is cumbersome to work with.
Re:I'm skeptical (Score:5, Interesting)
I think the emphasis has been misplaced; I think based on the process describe that they're actually measuring the *gravitational* field, which is not readily tampered with. It'd be like navigating based on a topo map, except instead of altitude it'd be using the local gravitational field below the device.
Supercooled superconducting gravimeters can be amazingly sensitive, to the point that one in Finland reportedly detected the increase in local gravity as workmen removed snow from the roof of the building it was housed in ;) If one can make use of tiny diode lasers to supercool a tiny group of particles, it could conceivably yield a low power, portable, super-precise, tamper-immune GPS when combined with dead-reckoning and/or other rough positioning mechanisms to help determine how you're moving over the "topographical" gravity map.
At least that's my take.
Re:Well ... (Score:5, Interesting)
This is only true because before the array of satellites deployed by the US military, there was no other system for finding your global position.
Not true. From the Wikipedia entry on the SR-71 [wikipedia.org]"Nortronics, Northrop's electronics development division, had developed an astro-inertial navigation system (ANS), which could correct navigation errors with celestial observations, for the SM-62 Snark missile, and a separate system for the ill-fated AGM-48 Skybolt missile, the latter of which was adapted for the SR-71.[50][citation needed]
Before each takeoff, a primary alignment brought the ANS's inertial components to a high degree of accuracy. Once in flight, the ANS, which sat behind the Reconnaissance Systems Officer (RSO)'s position, tracked stars through a circular window of quartz glass set in the upper fuselage.[37] Its "blue light" source star tracker, which could see stars during both day and night, would continuously track a variety of stars as the aircraft's changing position brought them into view. The system's digital computer ephemeris contained data on 56 (later 61) stars.[51] The ANS could supply altitude and position to flight controls and other systems, including the Mission Data Recorder, Auto-Nav steering to preset destination points, automatic pointing and control of cameras and sensors, and optical or SLR sighting of fix points loaded into the ANS before takeoff.[52] Former pilot Richard Graham told an interviewer at the Frontiers of Flight Museum that the navigation system was good enough to limit drift to 1,000 feet off the direction of travel at Mach 3."
I knew a guy who worked on this system. He told me about a time when they pulled one out of a plane for routine maintenance and they thought it was malfunctioning as it locked onto a star while in the hanger. After they couldn't find the fault they put a guy on a lift and turned all of the lights off in the hanger. Sure enough they found a pin hole in the roof that could only be seen close up in the dark. After they patched the hole, everything checked out fine.