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.