[daip] PBCOR question

[Eric Greisen]

Andrew Baker writes:
 > 
 > Dear AIPS Team,
 > 
 > I'm running the 31DEC03 version of AIPS that is installed locally, and am 
 > having some trouble with the PBCOR task.  Specifically, I'm getting output 
 > images that are identical to input images in all details.  My original 
 > attempt was to use PBPARM 0.1,1,0.2037,0.20747,0.14087,0.00071739 on an 
 > OVRO map that was created with IMAGR on another (31DEC99) installation and 
 > had FREQ in Hz added manually with PUTHE.  I also get input = output if I 
 > use PBPARM 0.9,1,100,100,100,100-- no blanking at all!-- which seems 
 > absurd if I have understood the documentation correctly.

PBCOR changed between 31DEC99 and 31DEC03.  The parameters describe
the beam not the inverse beam.  If all of your PBPARMS are positive
then the beam will everywhere be > 1 and PBCOR limits it to 1.0.

Task PBEAM may be able to help determine these parameter values.
Samples are in the help file.

 > 
 > Any suggestions for what I should do differently?
 > 
 > Thanks,
 > 
 > Andrew
 > 
 > P.S. - If Eric is fielding this one, congratulations on the Van Biesbroeck 
 > prize!

Thanks,

Eric Greisen