> the M12+'s pps jitter has a strong frequency component at a repetion > rate of 2 s. This component has a peak to peak value of 2-4 ns and is > almost unseen in the raw pps values. It is, however, clearly to be > seen
Where does that 2 seconds come from? Is that just one set of observations, or does it hold for most M12+s and most of the time? One of Said's graphs had a minor bump at roughly 2 seconds. I saw another graph with a small spike at 2 seconds, but I don't remember where. TVB's graphs show that the sawtooth period changes. I assume the sawtooth is the beat of the local OSC with the 1 PPS from GPS. I'm assuming the sawtooth graphs are derived from a greatly expanded temperature vs frequency graphs - similar to a Fresnel lens. The flat spots (suspension bridge) are not necessarily zero temperature vs frequency. They might be where the temperature is changing by an integral number of cycles per second per second. (It might be atmosphere or multipath that is changing rather than temperature.) So why does that cause a bump at 2 seconds? Why not 1 second or 5 seconds? It seems reasonable to filter out the 5 seconds, but I can't see how to filter out 1 second without also filtering out the 2 seconds. I think I'd expect a shoulder rather than a bump. It would fall off above 2 seconds and blend in below 2 seconds. -- The suespammers.org mail server is located in California. So are all my other mailboxes. Please do not send unsolicited bulk e-mail or unsolicited commercial e-mail to my suespammers.org address or any of my other addresses. These are my opinions, not necessarily my employer's. I hate spam. _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
