I mean "nearby". Sorry about that.

I suppose next time it may come out when I meant to say "early". Or "hearsay". Or "Furby".

The existing SBAS that we have here in Europe - European Geostationary Navigation Overlay Service (EGNOS) already alleviates this sort of issue by providing correction data to GPS receivers so that they can 'get the sums right'. Check 'ENGOS' and 'SBAS' on Wikipedia.

that none of these "solar flares" have ever happened already since GPS was brought into use. What terrible carnage would have occurred on any such occasion.

Obviously, uses of GPS that do not tolerate the measurement being as much as ten metres adrift of your real exact location must be terminated forthwith.

To be a little more realistic, I think it was hoped that Galileo was going to be that good, and now it isn't. GPS never has been.

Well. Wikipedia says: "Like the US GPS, use of basic (low-accuracy) Galileo services will be free and open to everyone. However, the high-accuracy capabilities will be restricted to military use and paying commercial users."

So unless you're building a business on high-accuracy paid-for location of your receivers, or are bombing somebody, this won't affect you, because GPS or Galileo aren't that good, anyway. If you are doing one of those things, it sounds as though you'd better not do it during heavy sunspots. Which may be an inconvenient limitation. And Galileo's operators may need to have a sit down and think.

Then again, the old encrypted GPS trick of fixing one location in your field of operations very accurately, and then calculating earby locations relative to your fixed point (Channel 4's archaeologist Time Team did or do that - I haven't watched for a while), will work, I think. But will we have convenient support for that in various uses of sat nav and positioning? Apparently we'd better. Unfortunately the cheapest equipment probably won't be that smart.

Scenario: docking a big oil tanker just up to the dock wall and no further, and those babies don't start and stop so well. Needs to be just right. Or does it...