On Sat, 04 May 2013 21:53:00 -0700 Hal Murray <hmur...@megapathdsl.net> wrote:
> Radio astronomers use H-masers. Can I assume that they are mid-term and that > H-masers are better than Rb (at mid-term)? Disclaimer: I'm not into astronomy. What i write below is solely based on what i've stumbled upon in the last years. It is probably inacurate and maybe even wrong. Modern H-Masers outperform both Cs beams and Rb Vapor Gas Cells siginificantly up to a couple of days to a couple of months. Which stability (short term or mid term) is exactly used for astronomy depends on the phenomena they want to observe and how often they can synchronize their clocks. The three most demanding applications are probably large antenna arrays, VLBI and pulsar rate measurement. Large antenna arrays mostly need short term stability, up to a couple of hours (the length of one observation). VLBI can take multiple days, depending on the setup. And pulsar rate measurement spans many months to a couple of years. Attila Kinali -- The people on 4chan are like brilliant psychologists who also happen to be insane and gross. -- unknown _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.