OK. Sme GPS receivers have magnetic sensors. What do they do with/about magnetic deviation.
-John ============== > Tom Van Baak wrote: >>> Does a stationary (not in motion) GPS receiver know where the North is? >> >> No, a stationary object is a point, not a line or a vector. >> The notion of North (or any direction) has no meaning >> to a point, by definition. > > You are mixing things a litte too much here. There is no direction > within a 0-dimensional space, but a point as it is positioned in a > 3-dimensional space has no problem to have an associated vector pointing > either to a location or along some field such as the magnetic field. > > An electron is a point-charge, and reacts to a magnetic field or the > electrostatic field. > > The antenna is certainly not a point, it is a sizeable object and it's > phase centrum isn't a point either, it's just a handy approximation. > > It's just that normal GPS antennas and receivers isn't built for this > purpose. A much smaller object than either the antenna or the receiver > is the SO-8 packaged magnetic sensor you can buy cheaply and sense the > magnetic field. A GPS receiver can be used to compensate for magnetic > deviation if needed. > > Cheers, > Magnus _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
