[daip] aips_gripe

[Leonia Kogan]

Lincoln,

I think the improvment does not have a sense if you mean VLBA correlator:

VLBA correlator makes a correction for the Earth rotation relatively its 
axis. As a result all array antennas are recalculated to the center of 
the Earth and the all spectra obtained at different antennas should not be 
shifted. 

The spectra are not shifted over the track. 
Therefore the shift at the center of an array is minimized to zero.

The all spectra together can be shifted in comparison with an 
other time observation. So the only reason using CVEL in the VLBA corralator 
case is to align the spectra of different time observation. 

Of course the situation can be different for another correlator. 

Leonia
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>From owner-daip at kochab.cv.nrao.edu Wed Sep 13 09:44 MDT 2000
Date: Wed, 13 Sep 2000 11:42:21 -0400 (EDT)
From: Lincoln Greenhill <lincoln at rgalp8.harvard.edu>
Subject: [daip] aips_gripe
Sender: owner-daip at kochab.cv.nrao.edu
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{13-SEP-2000 11:38:05}
{rgalp8       UN-REGISTERED!!!!!!!}
{   24  31DEC99  DEC}
{lincoln greenhill}
{cfa}
{617 495 7194}
{Suggested improvement for CVEL: A mode in which cvel will compute the
 velocity that minimizes the shift at the center of an array over the track
 and uses that in place of the SU table entry. It should then change the
 SU table entry for consistency.  This is probably most useful for line
 VLBI experiments.
  
 I am cognizant of limited manpower for AIPS development.
 -end
  }
{Suggested new CVEL mode - calc. velocity that minimizes shifts near array cntr.}
{greenhill at cfa.harvard.edu}
{ }


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