PRIMARY

        [CLEAN\]PRIMARY  [BeamSize]  [/APPLY Input Output] [/COMPUTE] [/CORRECT]
    [/TRUNCATE Fraction]

    Compute primary beam, apply it to images or correct single-field CLEAN image
    for flat-field.

    By default, with no option or only the /TRUNCATE option, correct  the  (sin-
    gle-field)  CLEAN  image from the (approximate) primary beam attenuation, in
    order to create the sky brightness image (named SKY).  The truncation  level
    is given by default by variable MOSAIC_TRUNCATE, and can be overriden by the
    /TRUNCATE option.

    The  primary beam model depends on the Telescope used in the data.  If Beam-
    Size (in radian) is specified, it is  a  Gaussian  with   the  corresponding
    half-power  beam  size.  If not, the parameters are taken from the telescope
    parameters, as found in the telescope section of the CLEAN image and the ob-
    serving frequency from the CLEAN image. For ALMA, the model is  the  Fourier
    transform of a uniform 10.4 m diameter disc with 0.7 m central blockage. For
    NOEMA  and  all  other  telescopes, it is a simple Gaussian with appropriate
    size.

    The SKY image is written with extension .lmv-sky by command WRITE.

    Options /APPLY, /COMPUTE or /CORRECT modify the default behaviour.  These  3
    options are mutually exclusive.