[daip] AIPS - Help

[Eric Greisen]

Murad Hamidouche writes:
 > I went through the suggested recipe in the cookbook to reduce my Q-band
 > data. However, I want to flag data that have an amplitude above certain
 > maximum amplitude, using CLIP task like this (the max amplitude I wanted
 > is 2 Jy) :
 > 
 > AIPS 1: CLIP      Task to flag data whose amplitude is out of range.
 > AIPS 1: Adverbs     Values                 Comments
 > AIPS 1: ----------------------------------------------------------------
 > AIPS 1: INNAME     '050417'                Input UV file name (name)
 > AIPS 1: INCLASS    'Q BAND'                Input UV file name (class)
 > AIPS 1: INSEQ         5                    Input UV file name (seq. #)
 > AIPS 1: INDISK        1                    Input UV file disk unit #
 > AIPS 1: OUTNAME    '050417      '          Output UV file name (name)
 > AIPS 1: OUTCLASS   'Q BAND'                Output UV file name (class)
 > AIPS 1: OUTSEQ        6                    Output UV file name (seq. #)
 > AIPS 1: OUTDISK       1                    Output UV file disk unit #.
 > AIPS 1: BCHAN         0                    Begin channel number.
 > AIPS 1: ECHAN         0                    End channel number.
 > AIPS 1: BIF           1                    First IF to consider
 > AIPS 1: EIF           2                    Highest IF to consider
 > AIPS 1: UVRANGE       0           0        UV range in which to apply
 > AIPS 1:                                    clip (kilo wavelengths)
 > AIPS 1: ANTENNAS   *all 0                  Antennas to consider 0=>all
 > AIPS 1: BASELINE   *all 0                  Baselines with ANTENNAS
 > AIPS 1: APARM         2           2        Flux range by polarization:
 > AIPS 1:               0           0        (1) = max. allowed parallel
 > AIPS 1:               0           0        (2) = max. allowed cross-pol.
 > AIPS 1:               0           1        (3) = min. allowed parallel
 > AIPS 1:               0           0        (4) = min. allowed cross-pol.
 > 
 > 
 > The task runs well but no data are flagged ? Even if I know that there
 > are bunch of visibilities above 2Jy and also checked this with UVFND task ?
 > 
 > Could you please let me know if there is any wrong parameter there?

     I don't see anything wrong here.  Note that CLIP is used on
single-source files not on multi-source files.  CLIPM is for
multi-source files and changes an FG table.  The data should be
flagged in the output file above (seq 6) not the input.  Are the data
multi-source, are there flag tables?

 > I used the task 'IMAGR' and the map is displayed in my terminal AIPS TV.
 > I want now to make a contours image that also shows the beam (RA . vs.
 > DEC) and save it in a ps file. I used the task 'CNTR' but I have got
 > something different than an RA,DEC image.
 > 
 > Could you please let me know how to make that kind of .ps file ? Or if
 > there is a step I may have skipped after IMAGR ?
 > 

What is the image?  IMAGR would make an ra-dec image on disk and an
image of the dirty beam as well.  Then you run KNTR to make a plot
file and LWPLA to make a POstScript file.  These are all explained in
Chapter 6 of the CookBook.
 
I may be able to help more with more detailed information - i.e. the
output of IMHEAD on the images (and the UV file in question 1).

Eric Greisen