My radio astronomer colleagues tell me that there is about a 20 minute limit to VLBI observing runs because of atmospheric instability so this limits improvements to be had from better clocks. My recollection is that a maser is still sufficient out to 100 GHz. There is a paper about this that I will dig out later.
Cheers Michael On Thu, 6 Jun 2019 at 12:01 pm, Joseph B. Fitzgerald < [email protected]> wrote: > > Regarding Dana's remarks on VLBI, consider the recent black hole image > released by the Event Horizon Telescope. Measurements were taken at 230 > GHz, and they would like to begin measurements at 345 GHz. Hydrogen > masers were used at each telescope. I am no expert, but I strongly > suspect that a better clock would result in longer/better observations. > The H maser only runs at 1.42 GHz ... the astrophysicist wizards are > proposing to do their measurements at about 250 times higher in frequency! > > > -Joe > _______________________________________________ > 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. > _______________________________________________ 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.
