[daip] CALIB question (Classic Aips)

[Samuel Conner]

To Whom it may concern,

  I am attempting to use the SMODEL parameter in CALIB (Classic AIPS, 31DEC2004, a July build) to correct the pointing on a calibrator scan in an archival observation (multisource data). I'm using a 2004 Goddard VLBI position, which differs from the historical scan position by about 75 mas.

  In earlier versions of CALIB, it was possible to set SMODEL = 1, delta-ra, delta-dec,0  to correct a pointing in a multisource UV datafile as well as single source files.

  It appears to me that this is no longer the case. The HELP file seems to imply that SMODEL only works with single-source UV data, and when I try to CALIB with SMODEL set or not set, the gain phases are the same (this in an A array C-Band observation, where I would expect substantial phase differences for a position offset this large).

  The HIstory file does list the SMODEL parameters, though they seem to have had no effect on the calibration.

Two questions:

A)  Am I missing something or is SMODEL indeed disabled in multi-source data?

B)  Would it be safe for me to adjust the coordinates in the SU table in order to achieve the same effect? 


Thanks for your time,

Sam Conner