[mmaimcal] Re: [alma-sw-ssr] question about frequency/band switching speeds and rates

[Ed Fomalont]

Hi Mark,

    Yes, your equation and the comparison of the thermal noise
and residual atmospheric phase fluctuation is the correct way to
look at fast switching.  One other consideration is the time spent
on the calibrator.  The trade-off between a strong but more distant
calibrator with a weaker but closer (to the target) calibrator is
also interesting.  The more distant calibrator, even if infinite in
strength may not be as good (in the sense of obtaining a better
dynamic range on the target source) as a weaker calibrator even if you have
to increase its integration time to 5 sec or so.  This consideration
depends on the angular correlation of the phase fluctuations.

Ed