[daip] POSSM problem

Trisha trisha.ashley at gmail.com
Wed Feb 23 16:26:01 EST 2011


Hello,
I am a graduate student at Florida International University, and while
working with AIPS I ran into a problem with POSSM.  I am concerned that
POSSM is not showing me everything that it is supposed to in both the '08
version (which I use regularly) and the '11 version (which I checked to see
if it was only the '08 version with this problem).

When using the following inputs:
    default POSSM
    flagver 1
    aparm 0, 1, 0.7, 1.3, -180, 180, 0, 2, 0, 0
    source ''
    solint -1
    nplots 9
    bparm 0
    dotv 1
    bpver 4
    getn *.LINCOP

and different FREQIDs I receive some strange (?) results for my
multi-frequency data.  The BP table I am plotting has had FREQID set to -1
using TABED and combines two FREQIDs (FREQID=1 and FREQID=2).  I have double
checked to make sure that the BP table has the freqid of -1 written in it,
and indeed it does.  The flux calibrator used for the BP table has six scans
(three for FREQID=1 and three for FREQID=2), and the last three scans (in
time) were deleted in stokes rr due to phase problems (one scan deleted from
FREQID=1 and two scans deleted from FREQID=2). The flux calibrator is being
observed at two different frequencies in order to avoid galactic
interference.
When:
I set (in POSSM) FREQID= -1 it shows me the first two scans (in time) from
FREQID =1,
I set (in POSSM) FREQID=1 it  shows me the first two scans (in time) for
FREQID 1
I set (in POSSM) FREQID=2 it shows me the first scan from FREQID 2,

Now, I have set FREQID=-1 for the entire bpass table, so after speaking with
some research team members I am under the impression that POSSM is looking
into the NX table to find the FREQIDs.  My main question is, if FREQID= -1
and SOLINT=-1, then I should see all of the scans for any frequency right?
In that respect, if it is not happy about having only the ll stokes for the
last three scans (because the rr stokes got deleted for those scans) and
thus it refuses to plot anything for those times, I could live with that,
but I would think that I should still see the first 2 scans of FREQID=1 and
the first scan of FREQID=2.

I have included the FITS file of my tables from this data set, but please
let me know if you need more information/data.
I hope that all made sense.  Thank you so much!-Trisha
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