SDI

        CLEAN  [FirstPlane [LastPlane]] [/PLOT Clean|Residu] [/FLUX [Fmin Fmax]]
    [/QUERY] [/RESTART [File]]

    with METHOD = SDI

    Perform a Steer-Dewdney-Ito CLEAN. This clean method selects an ensemble  of
    clean  components and remove them at once using FFTs.  It works best for ex-
    tended sources and UV coverages with short spacings. In such a case, it  may
    avoid  the  "ringing"  features which appear using the CLARK or HOGBOM tech-
    niques. In mosaic mode (see command MOSAIC), a mosaic clean is performed.

    SDI is very sensitive to the selected support (see  MASK  and  SUPPORT  com-
    mands), especially when the dirty beam sidelobes are significant.