[time-nuts] GPS altitude somewhat wrong?

[Mark Sims]

You have to be careful with a lot of modern GPS receivers.   Many implement some sort of "position pinning".   If they do not detect significant movement,  they either stop updating the coordinates  or heavily filter it...  you do not see the actual computed location.  On some receivers you have to move well over 10 meters before the position un-pins.
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> CEP(95) of 1.5 meters over 1,000 seconds.