Hi Demian, Did you make sure the altitude/height is using the same reference?
The GPS system measures relative an ellipsoid approximation of the earth. Sometimes this is used in receiver output messages. To translate this to "Mean Sea Level"/geoid you need to apply a location dependant correction. The GPS receivers will happily emit both height measures in different messages, its important to understand which is used in the specific messages you are comparing. Have it better explained in the below url: http://www.esri.com/news/arcuser/0703/geoid1of3.html Also not that height accuracy of GNSS is worse than its horizontal accuracy by almost a factor of 2. -- Björn > I have 2 GPSDO's. A Thunderbolt and an Arbiter 1083A. The Arbiter is old > but > it works fine (and has a Wenzel 5 MHz streamline oscillator in it). It has > the 1995 firmware issue, and I could get new firmware for it ($$) but I'm > not using it as a clock, just a frequency source. > > > > I just moved and have re-setup both. They share an antenna. I got both to > do > a self survey. The Arbiter was really close to what Google maps indicate > is > my location. The Thunderbolt was about the same except it has me > underground. The arbiter has the height as +30M. The Thunderbolt as -6M. > What setting do I have wrong in the Thunderbolt? Would it affect the > operation as a frequency standard in any way? > > > > > > Demian Martin > > San Leandro, CA 94577 > > > > _______________________________________________ > 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. > _______________________________________________ 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.