ALMA temporal phase stability and the effectiveness of water vapor radiometer

We present the temporal phase stability of the entire ALMA system. We first verified the temporal phase stability: We observed a strong quasar for a long time (a few tens of minutes), derived the temporal structure function after the atmospheric phase correction using the water vapor radiometers (WVRs), and confirmed that the phase stability of all the baselines reached the ALMA specification. We then verified frequency transfer between bands: We observed a bright quasar and switched between the two frequency bands, and confirmed that the phase returned to the original values within the phase fluctuation. In addition to these results, we also studied the effectiveness of the WVR phase correction at various frequencies, baseline lengths, and weather conditions.