UV_SHIFT
Keywords: imager

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##
UV_SHIFT

            [CLEAN\]UV_SHIFT   [CenterX  CenterY  UNIT]  [ANGLE  Angle]   [/FILE
        FileInOut]

        Shift  the  current (if no /FILE option is present) or specified (if the
        /FILE option is here) UV table (single field  or  mosaic)  to  a  common
        phase center and/or rotate it.

        Angle  is  desired position angle of the Celestial North from the Y axis
        (counted positive towards East, i.e. counter-clockwise in  usual  astro-
        nomical images), in Degree. It is thus an absolute value.

        If  UNIT  is  ABSOLUTE,  CenterX and CenterY are absolute coordinates in
        usual sexagesimal notation.

        If not, CenterX and CenterY are offsets in the  specified  angular  unit
        (SECOND, MINUTE, DEGREE or RADIAN).

        Although  UV_MAP also provides a direct possibility to re-center the im-
        age on a specified projection (phase) center cmobined with a rotation of
        the  main axes, the modified visibilities cannot be saved on file. It is
        sometimes required to do this for specific use. UV_SHIFT  provides  this
        possibility, and the shifted UV table can be written using command WRITE
        UV.

        UV_DEPROJECT includes the UV_SHIFT capabilities, but also has additional
        functions, and a different syntax.

Subsections

- UV_SHIFT /FILE