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Comment by adynatos | Hacker News Reader

could we use this on earth in the future?

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.

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)

Star trackers do exactly this, providing relatively accurate positioning without GPS:

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

Was going to say this, and in use by things like submarines and ships since the 60’s

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.

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.

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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