Posted on 11/12/2018 4:19:29 AM PST by BenLurkin
Scientists have demonstrated a "commercially viable" quantum accelerometer that could provide navigation without GPS or other satellite technology. The device uses lasers to cool atoms to extremely low temperatures, and then measures the quantum wave properties of those atoms as they respond to acceleration.
[T]his quantum 'compass' isn't ready to replace the accelerometer in your phone. It's only truly ready for ships, trains and other large vehicles where size and power requirements aren't major factors. It could keep transportation networks humming even if GPS fails outright. The researchers also expect the underlying concepts to help with science studies, such as looking for gravitational waves.
(Excerpt) Read more at engadget.com ...
I am proud to say that I and my team supported GPS testing before they went commercial.
Yuma Proving Ground was a test bed for the GPS concept.
People born after 1985 consider before GPS as similar too before the telegraph....
Getting old is not for sissies, as my mother used to say...
I smile every time I read one of these kind of articles. Scientists never demonstrate any commercially viable anything. Scientists demonstrate a scientific concept ONCE and then turn it over to engineers, where the hard work begins. It is not as easy as scientists (physicists in particular) think it is to get something from concept to production. Doing it once is not the same as making it a million times, cost effectively.
Knowing your location tells you nothing about the location of another train. Train tracks are well instrumented, and keeping trains from colliding is a dispatch job, not a navigator’s.
Inertial navigation is routine, and was “how it was done” on airlines before GPS, with various radio aides to navigation such as LORAN, OMEGA and DME. GPS has supplanted other forms of radio navigation. Modern navigation integrates GPS and inertial, but achieves satisfactory results with inertial only.
Beat me to it, sounds like a version of inertial.
It still has to know where it is at the start.
I flew 747-4, they used multiple GPS and Inertial systems, that worked together.
Isn’t this what Leonard, Sheldon, and Howard were working on?
Sure sounds like it.
Maybe this is what happened to it when the military took it over.
Certainly, but not so well instrumented that the dispatcher can tell where every car is. In long trains, there is enough slack in just the couplers, that the length of the train can vary by far more than one car length.
What is known in the business as “margin of error”. I’m sorry, I just don’t see any use for quantum navigation on railroads. Trip switches driving signal lights alert dispatchers and drivers when a piece of track is occupied. Trains are not supposed to pull into an occupied station. Casey Jones tragedy resulted when a train stalled on a track ahead of him, and he was exceeding the speed limit to arrive on time after a delayed departure. Even without radio communications, the conductor of the other train should have deployed signal flares in plenty of time. Accounts vary, but Jones’s fireman survived (”Jump, Sam, jump”) and testified that they did not see signal flares. In the end, the Illinois Central Railroad blamed Jones. (”That’s a good engineer a-lying there dead”)
Inertial navigation systems drift. GPS is too slow. Use GPS to correct INS drift, use INS to get immediate (millisecond latency) attitude, orientation and quick response to maneuvers.
Trains wouldn’t use it for navigating, but for tracking and switching trains.
Right, and every century, or so, it's usually good to upgrade to improved technology.
What does “quantum navigation” supply that a tripping switch doesn’t? Other than expense?
True. But trains today do have much better technology, including radio dispatch. Today, Jones would have known about the blockage hours ahead of time.
“Unless, of course, you wat to make sure there’s not another train on the same track or siding. Have you ever seen an overpass for trains, like you see for automobiles? “
... or you’re operating a train that lays its own track.
Submarines would love this, since they can’t get GPS signal while submerged.
Precise location and speed at any given moment.
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