[daip] FLATN

[Eric Greisen]

On 09/20/2015 07:25 PM, Lawrence Rudnick wrote:
> Some issues with FLATN, inputs are below.  Trying to put together whole
> NVSS survey, with preprocessed reduced images. This kind of thing has
> worked well in past with '-ait' COOTYPE.
>
> If I use cootype '-NCP', the header on the output file says it's SIN
> projection.
>
> If I use cootype '-MER', with everything else the same, it doesn't
> include any fields in the output, so just makes an unfilled map with
> -1e20 to +1e20 in header and no valid pixels.
>
> thanks.  lr
>
>
> AIPS 1: FLATN: Re-grid multiple fields and pointings to one image
> AIPS 1: Adverbs     Values                 Comments
> AIPS 1: ----------------------------------------------------------------
> AIPS 1:                                    Input images
> AIPS 1: INNAME     'NVSS_OPN11Z'              Image name (name)
> AIPS 1: INCLASS    'IO0001'                   Image name (class)
> AIPS 1: INSEQ         1                       Image name (seq. #)
> AIPS 1:                                          (specify)
> AIPS 1: INDISK        2                       Image disk drive #
> AIPS 1: NFIELD     2326                    Max number of fields per
> AIPS 1:                                       pointing
> AIPS 1: NMAPS         1                    Number of pointings
> AIPS 1:                                    Output image
> AIPS 1: OUTNAME    ' '                        Image name (name)
> AIPS 1: OUTCLASS   ' '                        Image name (class)
> AIPS 1: OUTSEQ        0                       Image name (seq. #)
> AIPS 1: OUTDISK       1                       Image disk drive #
> AIPS 1: IMSIZE     6480        3240        Output image size in pixels
> AIPS 1: COORDINA     12        *rest 0     Central pixel coordinate
> AIPS 1:                                    all 0 => use observed
> AIPS 1: COOTYPE    '-MER'                  Desired projection type
> AIPS 1: COOINC      -40          40        Desired coordinate increment
> AIPS 1: COOREF     3240        1620        Desired reference pixel
> AIPS 1: ROTATE        0                    Rotation to be used (deg)
> AIPS 1: REWEIGHT      4           0        (1) Interpolation halfwidth
> AIPS 1:                                    (2) Minimum fraction of good
> AIPS 1:                                        pixels required (0->1/3)
> AIPS 1: WEIGHTIT      0                    Weight image down by WEIGHTIT
> AIPS 1: ** press RETURN for more, enter Q or next line to quit print **
> #
> AIPS 1:                                    times radius from center in "
> AIPS 1: EDGSKP        2                    Skip pixels around the edges
> AIPS 1:                                    inscribed ellipse also used
> AIPS 1: OPTYPE     ' '                     For mosaics only (NMAPS>1)
> AIPS 1:                                    compute and output expected
> AIPS 1:                                    noise ('NOIS') or weight
> AIPS 1:                                    ('WEIG').
> AIPS 1: APARM      *all 0                  (1) >0 => do 3-D corr.
> AIPS 1:                                       ONLY for snapshots
> AIPS 1:                                    (2) Parallactic angle (deg)
> AIPS 1:                                    (3) Zenith angle (deg)
> AIPS 1:                                    (4-8) radial scaling parms
> AIPS 1:                                    (9) Linear scaling
> AIPS 1: PBPARM        1           1        Beam parameters (NMAPS > 1)
> AIPS 1:            *rest 0                 (1) Cutoff; (2) Use (3)-(7)
> AIPS 1:                                    (3)-(7) Beam shape
> AIPS 1: NOISE      *all 0                  Relative uncertainties by
> AIPS 1:                                    pointing: 0 -> image header
> AIPS 1: BADDISK    *all 0                  Disks to avoid for scratch

You say to use PBPARM values 3-7 and set them all to zero.  That does 
mean no primary beam.  I suspect that should not matter with NMAPS=1 but 
fix it.

Also try EDGSKIP=-1

If that does not work, try sending me some real information such as 
IMHEADERs, output from FLATN, output IMHEADER, etc.

ERic Greisen