[daip] application of calibration in aips

[Eric Greisen]

Juan Uson writes:
 > 
 > Hi Eric,
 > 
 > I hope that your father is doing well and that you feel ok too.
 > 
 > I have a question on aips calibration and I was wondering if you can  
 > tell me (Bill is somewhere in Europe or on a plane to or from).
 > 
 > How is calibration actually applied in aips?  I understand that  
 > solutions in an sn table can be interpolated into the cl table but it  
 > is not clear to me how a discrete cl table is actually applied to the  
 > data when docal=1 or 2.  Is any interpolation done at this stage?  Is  
 > it nearest entry in time?  Previous entry?

     2-point interpolation is used between the entries in the CL table
surrounding the particular time.

Eric
 > 
 > I am trying to track down some strange behavior in very recent data  
 > and cannot make sense of the difference in phases from dumptime  
 > solutions (1.66 sec) with and without a calibration applied (standard  
 > entries in the cl tables).
 > 
 > For now, I am going to make a new cl table with entries every 1.66  
 > sec with indxr.  However, I should like to know what usually  
 > happens.  By the way, this is all on 3C84 so signal to noise ratio is  
 > large.
 > 
 > Cheers,
 > 
 > Juan