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World's first GPS-free quantum navigation trial succeeds at sea (interestingengineering.com)
submitted 5 days ago by to c/technology@lemmy.world
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[–] 13 points 4 days ago (2 children)

The realer play is submarines. You don't get any satellite signal at all underwater. Before this it was only INS or dead reckoning.

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  • [–] 3 points 4 days ago (2 children)

    I suspect submarines can also use bottom facing radar to track features on the sea floor. But tracking the gravity should be even better.

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  • [–] 8 points 4 days ago (1 child)

    Radar is radio, just like most satellites. It doesn't do well through water. And that would require emissions, which submarines like to avoid.

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  • [–] 6 points 4 days ago

    I'm guessing they meant sonar instead. AFAIK active sonar does work really well, but is rarely used since it reveals your location twice as far as you're able to detect others. Not to mention the horrible effects on wildlife - the sound waves carry so much energy that a point-blank hit is somewhere between "lethal & untreatable" and "turned into red mist".

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