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A comment on What If GPS Stood for “Galactic Positioning System”?. Parent comment

Re:What If GPS Stood for “Galactic Positioning System”? by jannic on Friday February 02, 2018 @04:39AM (#16289452)
Just a guess: In priciple, yes, but it wouldn't be very practial. Because of noise sources on earth, one would need very big antennas pointing to the pulsars to get good s/n ratios. Additionally, as x-rays are blocked by the atmosphere, one would be limited to longer-wavelength pulsars, again increasing the size of the antennas. Given that, using GPS, we already have a positioning system much more accurate, I don't see why one would use pulsars for positioning on earth.
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Re:What If GPS Stood for “Galactic Positioning System”? by tomalpha on Friday February 02, 2018 @04:53AM (#16289506)
It does, perhaps, have the advantage of not needed a satellite fleet to work. So therefore isn’t at the whim of said fleet’s owner, or someone with anti-satellite missiles.

(Granted that the antenna size problem might be a killer)

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Re:What If GPS Stood for “Galactic Positioning System”? by gambiting on Friday February 02, 2018 @06:38AM (#16289814)
Star trackers do exactly this, providing relatively accurate positioning without GPS:

https://en.wikipedia.org/wiki/Star_tracker

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Re:What If GPS Stood for “Galactic Positioning System”? by MayeulC on Friday February 02, 2018 @07:46AM (#16290100)
I was about to suggest the use of a sextant for this. As far as I know, navigators are still trained to operate them in this day. Of course, the same operational principle can be integrated into a dedicated device.
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Re:What If GPS Stood for “Galactic Positioning System”? by oceanswave on Friday February 02, 2018 @07:32AM (#16290022)
Was going to say this, and in use by things like submarines and ships since the 60’s
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Re:What If GPS Stood for “Galactic Positioning System”? by kawfey on Friday February 02, 2018 @09:35AM (#16290740)
I thought this was more of a thought experiment for galactic travel, that would make the most sense. However navigation by star triangulation is much less complicated and historically proven ever since ships were sailed. Star trackers are on many satellites and rovers for positioning.
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Re:What If GPS Stood for “Galactic Positioning System”? by tlrobinson on Friday February 02, 2018 @09:50AM (#16290846)
Even some military aircraft like the SR-71: http://www.thedrive.com/the-war-zone/17207/sr-71s-r2-d2-coul...

Does star navigation work once you’re far beyond locations where we’ve previously been able to map stars from? Or put another way, is our "3D" map of the stars sufficiently accurate, or is it more of a "2D" map.

Perhaps you could update the map as you move (SLAM?)

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