Hi I don’t speak for Trimble and their interpretation of all this may be a bit unique. Normally what the 15 ns means is the time out of a simulator compared to the 1 pps out of the module. Put another way, it’s just a measure of the receiver. It does not include any ionosphere / troposphere issues. It assumes a perfect estimate of the location (no bias from antenna multipath). IT also does not take into account any delay in the antenna or coax to the antenna. Time errors between Glonass and GPS are not included (bad broadcast offset estimate etc). Finally there is the fairly important qualifier of “one sigma” on the 15 ns number.
All that said, two devices with the same antennas, same cables, close to each other, looking at the same sats, using the same systems, … should track pretty well. Bob > On May 25, 2017, at 9:27 AM, Ebrahim Roghanizad <[email protected]> > wrote: > > Dear members > > I am a new amateur member in your group. Maybe my question has been asked. > Recently I found Trimble Mini-T GG, whose data sheet is attached, as a good > GNSS disciplined time reference. I would like to know if there exists a > more accurate one, since it does not employ dual frequencies to compensate > ionospheric delay, though it handles both GPS and GLONASS. Besides, could > anyone guide me about the presented accuracy in the datasheet? There, it is > stated that "When operating in Over Determined Timing Mode, the accuracy of > pulse per second (PPS) is within 15 nanoseconds of GNSS/UTC." Does it mean > that it includes both bias and the noise? In other words, is it true to say > that "The time-synchronization error between two of them with a long > distance is less than 2*15 ns"? > > Best Regards > <Trimble Mini-T GG.pdf>_______________________________________________ > 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. _______________________________________________ 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.
