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. xyzzy_plugh · 1790197763 · focus · HN ↗

         Actually it hasn't proliferated into civilian use because the military industrial complex has captured pretty much anything with real accuracy.

         I had an old colleague who in a previous life worked on an incredibly accurate positioning system that was effectively a brief case that knew where it was at all times. The story he told was the DoD made them an offer they couldn't refuse, and everything became secret. I'm pretty sure the company in question is still in business.

         I'm not trying to say it's not legal but it might not exactly be legal?

         1. buran77 · 1790201969 · focus · HN ↗

            > the military industrial complex has captured pretty much anything with real accuracy

            Real accuracy is a matter of application. For mainstream civilian use the 20-30cm offered by Galileo/GPS is beyond real accuracy. It gets even better for specialized civilian use or with the aid of differential GNSS (low single digit cm). You'd have to think real hard for a reason to need better precision on a global scale especially if that involves any extra cost.

            Can't say how much of a priority accurate positioning would be for civilians during an armed conflict.

Unofficial Hacker News client; not affiliated with Y Combinator.