[Arbalest]

I'm going to wager the answer is, no. By and large, the main advantage of GPS is it is now extremely compact and relatively low power. My gut feel: To do the same with the sun and stars, you need very finely calibrated optical instruments, probably on a motion compensated surface to get maybe 1/10th of the precision. Also a precise timesource would need to be thermally compensated etc. That's not portable or low power and I don't really see how portable that can be made. The inertia + gyros thing is already used by GPS systems as a backup when traveling in tunnels.

[loriverkutya]

The answer is yes: https://www.thedrive.com/the-war-zone/17207/sr-71s-r2-d2-cou...

[foxyv]

If we spent some time I bet we could come up with a laser gyros small and affordable enough for phones or at least small navigation units. The bad part would be having to align your INS every day or two. Or if it restarts...