On Mon, Jan 5, 2009 at 9:27 PM, <[email protected]> wrote: > Hi Matt, > > having 140ps matching of the 1PPS between units is the equivalent of knowing > your antenna position to within ~0.14 feet total error max. > > Thats less than one inch error per antenna!
That makes it sound a lot more difficult than it really is. The vast majority of the error in GPS is systematic, such that two GPS systems with antennas near each other should have highly correlated error. This is the basis of differential GPS. It doesn't matter if the absolute error is hundreds of feet, as long as both devices have the same error. I spent a couple of years nearly a decade ago doing differential GPS for steering heavy equipment. You can get sub-centimeter errors over baselines in the tens of km. Again, this is relative error. Matt _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
