Next message: Jared Sherman: "Re: lack of manufacturer's non-adjustable error information for mysextant......."
Trevor-
<I don't know the details of this case but I imagine that it is because
the satellites provide more accurate measurements >
I think the new accuracy of satellites comes from the fixed orbital physics involved. The path of the satellite, the spherical nature of it (or not<G>), can all be defined, predicted, and conformed by observations from one orbit to the next. From various ground stations with telescopes and synchronized atomic clocks. Or in the case of GPS, onboard atomic clocks.
Then the satellite, and precisely timed observations of it, provide a much more precise "rod and chain" to measure the underlying distances with. An invisible rod and chain, but a surprisingly rigid one.
