1 MAKE_MOSAIC Build a dirty mosaic from individual fields (suited only to MAPPING)

    This  task  combines  individual dirty images and beams corresponding to
    various pointing centers into a "mosaic" which is suited for further de‐
    convolution using the MAPPING program.

    Mosaics  are  ensemble  of overlapping fields, with typically half power
    primary beam overlap, and similar (but not identical) UV  coverages  for
    each  field. Individual images for every field should be created with  a
    common phase tracking center. The UV_SHIFT, MAP_RA  and   MAP_DEC  vari‐
    ables in task UV_MAP must be used for this.  The image names must derive
    from a generic name as follows (e.g. for a generic name  MAP)
         MAP‐1.LMV, MAP‐2.LMV, ... MAP‐N.LMV
    where N is the number of fields.

    For example
    LET MAP_SIZE 256 512
    LET MAP_CELL 0.5
    LET UV_SHIFT YES
    LET MAP_RA     20:39:10
    LET MAP_DEC    68:01:20
    !
    LET WCOL 1
    FOR I 1 TO 10
    LET NAME CONT‐’I’
    GO UV_MAP
    NEXT

    MAKE_MOSAIC produces a combined image (MAP.LMV), a data cube of  primary
    beams  (MAP.LOBE),  a  data cube of dirty beams (MAP.BEAM), and a weight
    image MAP.WEIGHT, which are required for cleaning.

    Two parameters are very important in the mosaic  creation:  the  primary
    beam  width (FWHM), and the truncation threshold of the primary beam. It
    is recommended to use a relatively high value for this threshold, 0.2 to
    0.4, to avoid contaminating adjacent field in case of pointing errors.

2 FIELDS$
        TASK\INTEGER "Number of fields" FIELDS$

    The number of fields in the mosaic.

2 NAME$
        TASK\CHARACTER "Generic file name (without extension)" NAME$

    The generic name of the mosaic. The names of the individual field images
    is derived by appending the field number, e.g. map‐1 map‐2  etc..,  when
    NAME$ = map.

2 BEAM$
        TASK\REAL "Half‐Power Primary Beam (in radians)" BEAM$

    The half power primary beam of the antennas, expressed in radians.

2 BMIN$
        TASK\REAL "Truncation Threshold" BMIN$

    The  minimum  relative intensity under which the primary beam of the an‐
    tennas should be set to zero. A value of 0.2 to 0.3 is recommended.
1 ENDOFHELP






