Why Google Maps is often wrong about your exact location

How does Google Maps account for plate tectonics? That's the seemingly simple question that led George Musser to unearth some fascinating facts about map-making, history, and the accuracy of modern GPS systems. Turns out, not only does the crust of the Earth, itself, move, but so do the locations of lines of latitude and longitude. Both those things contribute to small errors when your GPS tries to pinpoint exactly where you are.

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  1. I love these moments--combining high tech, grandfathered bureaucratic standards and science. Especially the bits about the grandfathered standards--reminds me of the joke regarding the origin of road and rail widths.

  2. This is a bit silly. GPS has +/- 30 METERS precision. Everything else mentioned here is a rounding error in comparison to that.

  3. phuzz says:

    If you take many GPS readings over a period of time in the same place you can get much more accurate positioning.
    With the right equipment you can get an error of a few cm (in the horizontal dimensions) in an hour or two.

  4. I think military GPS is a lot more accurate, but it's dumbed down for the enemy, such as civilians.

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