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post #6 of Old 11-10-2019
outbound
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Re: Path used to compute bearing and distance by GPS?

Until accurate clocks that would function at sea were invented folks sailed fixed latitudes. No need for changing course while following a fixed latitude. Given they were using magnetic compasses not a true shortest great circle but due to magnetic variation not a rhumb line great circle issue. Earth isn’t a perfect sphere mildly flattened not apple so you’re right rhumb and great circle will vary some depending upon what latitude. True even with a fluxgate compass. Think we need someone who knows more about the engineering of gps use to answer this question. It remains a good question. How does the software work? Understand how you get a position from it but don’t understand how the software uses that. Question remains how to get to the shortest great circle.

s/v Hippocampus
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Last edited by outbound; 11-10-2019 at 07:44 PM.
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