AIPS HELP file for SDMOD in 31DEC24

As of Thu Apr 25 13:54:42 2024

HELP SECTION

SDMOD
Task:  This task will SUBTRACT a model FROM single-dish "uv" data (if
       FLUX < 0) or replace those data with a model plus random noise.
       The model consists of up to four Gaussians, each of which will be
       convolved with the "Clean beam" parameters in the data header
       which are meant in this case to be the single-dish beamwidth.
       Alternatively, the model can be an image which is subtracted from
       the data or which replaces the data.
Adverbs:
  INNAME.....Input UV file name (name).      Standard defaults.
  INCLASS....Input UV file name (class).     Standard defaults.
  INSEQ......Input UV file name (seq. #).    0 => highest.
  INDISK.....Disk drive # of input UV file.  0 => any.
  IN2NAME....Input model image name (name).      Standard defaults.
  IN2CLASS...Input model image name (class).     Standard defaults.
  IN2SEQ.....Input model image name (seq. #).    0 => highest.
  IN2DISK....Disk drive # of input model image.  0 => any.
  OUTNAME....Output UV file name (name).     Standard defaults.
  OUTCLASS...Output UV file name (class).    Standard defaults.
  OUTSEQ.....Output UV file name (seq. #).   0 => highest unique
  OUTDISK....Disk drive # of output UV file. 0 => highest with
             space for the file.
  OPTYPE.....Operation: 'IMAG' => use IN2NAME et al. to provide an image
             of the model (taken to be a continuum image)
  BCHAN......First spectral channel to include: 0 => 1
  ECHAN......Last spectral channel to include: 0 => highest
  BIF........First IF to include: 0 => 1
  EIF........Last IF to include: 0 => highest.
  NGAUSS.....Number of sources in model: 1 - 4  Used if OPTYPE is not
             'IMAG' .
  GMAX.......Peak brightness of component in the units of the "uv" data
             (normally Kelvins).  To subtract a component from the data,
             set GMAX < 0.  The peak used is GMAX if the component or
             the antenna beam have 0 width, otherwise it is reduced by
             the ration of the area of the input component to the
             convolved component.
  GPOS.......(X,Y) position of the component in arc seconds from the
             reference position.  GPOS(1,*)/cos(declination) is the
             offset in right ascension,  (> 0 -> the component is East
             of the reference point) and GPOS(2,*) is the offset in
             declination (> 0 place the component North of the refernce
             position.)
  GWIDTH.....The Gaussian widths: GWID(1,*) is the major axis, GWID(2,*)
             is the minor axis both in arc sec and GPOS(3,*) is the
             position angle (from North to East to major axis) in
             degrees.  Each component will be convolved with the
             single-dish beam width (found in the header) before being
             applied to the data.
  APARM......List of center and fwhm in channels (in the input uv data
             set) for Gaussian spectral form for the components.  A
             width of zero => channel independent.  Thus 29, 3, 37, 5, 0
             specifies the first 2 components are also Gaussian in
             channels centered on input channels 29 and 37 with fwhms of
             3 and 5 channels, and the other 2 components (if any) are
             constant in frequency.
  FLUX.......>= 0 => Replace the input data with the model plux noise of
                     rms = FLUX in the units of the uv data (usually K)
             < 0  => Add the model (with no noise) to the input data.
             FLUX is used with both Gaussians and IMAGe.
  BPARM......Parameters for modeling beam-switched continuum data.
             (1) > 0 => these are such data.  The main effect of this
                 is to include the throw and to ignore the recorded
                 center coordinate.  The channel adverbs are ignored.
             (2) Correction factor for the throw.  0 => 1
             (3) Rotation of throw from horizontal CCW in degrees.
             Parameters applying to all data sets:
             (4) RA or Az increment in arc seconds (0 => none).  The
                 coordinates are forced to be the nearest integer
                 multiples of this increment.
             (5) Dec or El increment in arc seconds (0 => none).  The
                 coordinates are forced to be the nearest integer
                 multiples of this increment.
             (6) RA or Az shift in arc seconds applied after the
                 increment correction.
             (7) Dec or El shift in arc seconds applied after the
                 increment correction.
             (8) > 0 => correct the coordinates and then compute the
                 model, else compute the model and then correct the
                 coordinates.

EXPLAIN SECTION