SharpCap adjustment of System Clock using QHY174-GPS
Posted: Sat May 01, 2021 4:21 am
After the QHY174M-GPS gets a good lock on the signal, SharpCap offers to sync the computer's System Clock with GPS. Even after stabilizing for 20 minutes or longer, SharpCap continues to report a difference of 0.1 - 0.2 second between GPS and the System Clock.
What's puzzling is that the computer's Windows Clock is already synced to a GPS time server on my home network using Meinberg NTP. Meinberg NTP is very good at syncing time, and usually keeps the Windows Clock synced to within +/- 10ms of UTC.
Are the System Clock and the Windows Clock the same thing? If so, I don't understand why SharpCap and Meinberg NTP would show a difference of 0.1 - 0.2 second, when both are synced to GPS.
I am putting this forth as anecdotal data. I have not collected hard numbers yet to show how the difference between SharpCap and Meinberg changes as a function of time.
Andy Howell
Gainesville, FL
What's puzzling is that the computer's Windows Clock is already synced to a GPS time server on my home network using Meinberg NTP. Meinberg NTP is very good at syncing time, and usually keeps the Windows Clock synced to within +/- 10ms of UTC.
Are the System Clock and the Windows Clock the same thing? If so, I don't understand why SharpCap and Meinberg NTP would show a difference of 0.1 - 0.2 second, when both are synced to GPS.
I am putting this forth as anecdotal data. I have not collected hard numbers yet to show how the difference between SharpCap and Meinberg changes as a function of time.
Andy Howell
Gainesville, FL