Thread

1. gorgoiler · 1790191708 · focus · HN ↗

   Presumably when World War 3 kicks off the very first thing each adversary will do is knock out their opponents satellites? These are like flying lightbulbs that shine down usefulness from above, so step one is to cut the lights.

   Presumably-squared there is some kind of military backup to survive once the lights (GPS) go dark? Whatever that technology is, why hasn’t it proliferated into civilian life so that we all benefit from a resilient, non-GPS backup?

   Perhaps the answer is that every tank has a 10lb inertial navigation gyro or some other thingy in it as a backup, and the platoon around it uses the tank as a moving trig point? In that case I can see it being infeasible to deploy that for civilians.

   Perhaps-squared it’s just economics — GPS is cool and cheap now, so why burn profit margin on developing an alternative?

   1. PJDK · 1790193768 · focus · HN ↗

      I think the general assumption is GPS is denied in most combat zones, it's constantly being jammed in and around Ukraine.

      For most things the fallback is going to be everything we used to use. Maps, stellar navigation, inertial navigation that sort of thing.

      Guided weapons wise, terrain mapping is pretty common for cruise missiles. Storm Shadow, for example uses GPS, terrain and inertial guidance systems. Trident uses inertia and stellar navigation.

      As for why it hasn't proliferated into civilian use? Mostly it has its just the old things. You can perfectly well drive your car with a road map and sign posts. Pilots still train to use dead reckoning and beacons. Etc.

      1. SJC_Hacker · 1790209778 · focus · HN ↗

         GPS is generally jammed close to the target, to varying degrees. For intermediate guidance out of range of jammers it works fairly well

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