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We report results from re-analysis of the visibility data of the first 2-beamobservations with VERA (VLBI Exploration of Radio Astrometry), previouslyreported by Honma et al., 2003 (hereafter A2003). Independently we checked thearchival data and found the features noted in A2003 were not from the effect ofphase referencing by simultaneous differential VLBI but mainly from a removalof large phase change by subtracting an arbitrary fitted curve to the phasevariations.  The differential phase of the observed H2O masers between W49 North (W49N)and OH~43.8-0.1 did not show a sinusoidal variation with a period of onesidereal day due to a positional offset from the real celestial positions. Wetherefore could not reproduce the results in A2003 by a normal positionalcorrection estimated from all time data, but could reproduce almost the samephases only for the first hour by adjusting parameters. Using the parameters,we could not suppress the large amount of phase variations for the successivetime data that A2003 did not show in their paper.  It is appropriate to regard the analysis in A2003 as not being proper forshowing the performance of the instrument for phase referencing, which shouldbe demonstrated by other experiments observing several pairs of continuumsources.

Re-analysis of the First Fringe with 2-Beam in the VERA System from Archive Data