3 ms·
What's even more amazing, is that differential GPS works at all, given that it relies on measuring the timing of the underlying carrier signal. (As opposed to t
by beerandt 7y ago
What's even more amazing, is that differential GPS works at all, given that it relies on measuring the timing of the underlying carrier signal. (As opposed to the pseudo code.)
It takes the advantages of digital signaling, and throws them out, instead measuring the analog carrier waves directly. That this can be done at such low signal levels is unbelievably impressive.
(The statistical methods involved in getting an initial signal lock are nearly as impressive.)
And the whole thing was a 1980s hack for land surveyors to get better than 100m accuracy while systematically eliminating uncertainty due to Selective Availability (SA).
It's a hack that improved the overall accuracy of the system from ~100m to sub ~1cm, and eventually sub ~1mm accuracy, when used with some other methods.
4+ orders of magnitude improvement! From a hack!