> Daer Tom, > > Thanks very much for your reply. I not only see very good answer, > by reading your mails(and other replies from )I also got some > idea of how you reasoning the answer. Thats most valuable for me. > > Another thing, I remembered you said once that all stabilities are > relative. When I saw your chart of ADEV for some of your best > frequency source at: http://www.leapsecond.com/museum/manyadev.gif > what is your reference? especially when you measure the two > H-Masers in long time interval? > > Cheers, > > Lymex, BG2VO
Those plots were made from raw data so strictly speaking they are all relative. But the frequency reference in most cases was a maser so I didn't "subtract the background". The plots of maser vs. maser were also relative so theoretically the performance of each maser might be a little better at certain tau than either of the two plots show. For example if two masers have a stability of 9e-14 for some tau you might be able to assume the actual stability of each one at that tau is 6e-14 (since 9 / sqrt(2) = 6). The right way to do it is with a "3 cornered hat". If you have three clean pair-wise runs of three similar frequency standards then you can use a 3 cornered hat to isolate the stability of each of the three standards. The three lines of code that do this are at the end of: http://www.leapsecond.com/tools/3hat.c /tvb _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
