> Thanks for that. Another question to show my ignorance of GPS. You > said elsewhere that a view of 4 satellites was needed. I've often > wondered why so for time keeping? I can see why for positioning, but > I can't help thinking with a static unit surely it should be able to > work out the time from one providing you accurately tell it where it > is?
Some GPS units have 2 versions of software: one for position and another for time. If you don't know either position or time, it takes 4 satellites to give you 4 equations so you can solve for the 4 unknowns: X, Y Z, and T. Extra satellites let you check things and/or give a better estimate of the accuracy. If you know the position you can get time info from 1 satellite. More get you better data and/or a better estimate of the accuracy. If your GPS unit is stationary, you can get the position by averaging over many readings. GPS units with timing software have a "survey" command to do that. -- The suespammers.org mail server is located in California. So are all my other mailboxes. Please do not send unsolicited bulk e-mail or unsolicited commercial e-mail to my suespammers.org address or any of my other addresses. These are my opinions, not necessarily my employer's. I hate spam. _______________________________________________ timekeepers mailing list [email protected] https://fortytwo.ch/mailman/cgi-bin/listinfo/timekeepers
