); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY [EMAIL PROTECTED] wrote: > Hi HMurray, > > depends on the GPSDO. On the Fury for example you can expect the unit to > wander less than +-15ns back and forth over a period of 1 Day. That's a > deviation of about 3.5E-013 or so per 24 hours. > > This wander depends on how good the hold position is that is set inside the > GPSDO's GPS receiver, as well as the stability of the OCXO, and the quality > of > the GPS receiver. > > All standard GPS receivers have problems with height: > > We see a range of about +-2 Meters max on the height on the Motorola M12+ > receiver on different Fury units for example. The newer M12M motorola/iLotus > receiver is slightly better than this. > > This would lead to a worst case error of up to 12ns just due to this antenna > position error, slightly more than a good Cesium would wander. > > Said > > > Said
Where does the 12ns figure come from? Surely a height error of 2m leads to a timing error of about 6.6ns for a particular SV when that SV is directly overhead. When the SV isnt directly overhead a 2m error in height contributes less error than this to the slant range and the corresponding propagation delay error from the SV to the antenna will be less than 6.6ns. Bruce _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
