-------- In message <bn7pr07mb5297caa7a73c8107c94b6d6fce...@bn7pr07mb5297.namprd07.prod. outlook.com>, Mark Sims writes:
>For all the receivers that I have tested there is only one combination >that jumps out as being the correct one. However, for the new >Ublox F9P, there are two combinations that produce virtually identical >measurements and statistics (add current sawtooth or subtract >previous sawtooth). That is a pretty natural pattern, which has been evident to varying degrees, from the very first Oncore-UT models. >Any ideas on how to determine which combination is the "correct" one? Absent input from the manufacturer, you will have to measure it. What you are looking at is off-by-one events caused by mispredictions of the clock-rate which straddle the "use this or next flank" threshold of the PPS signal generator. If you temperature cycle the GPS, these events will happen more often. After (mis-correction) these events show up as spikes of almost one clock-period outside the normal band, at the "towers" of the "hanging brides". In other words: Standard deviations and variances is not the right tool, you are looking for outliers at a quite distinct distance (+/-) from the mean. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [email protected] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
