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Basic Information on demos
Task: demos
Purpose: Inverse mosaicing operation
Categories: map manipulation
DEMOS (de-mosaic) is a MIRIAD task that takes a model of the sky
(that is primary beam corrected), and multiplies by a primary
beam response function at a number of different pointing
centers. It produces a different output for each pointing
center. Thus this task performs the inverse of mosaicing. The
input pointing centers and the primary beam size are indirectly
specified by a visibility dataset.
Because the output of DEMOS have primary beams applied, they can
be used for comparison with visibility data and uncorrected
images. In particular SELFCAL cannot handle a model that is
primary beam corrected, though it can handle a visibility data
file containing multiple pointings. Thus you could use DEMOS to
break the model into several models which are not primary beam
corrected.
Key: map
This is the name of the image to be de-mosaiced. A primary beam
corrected image, single dish image, or one that is partially
primary beam corrected (e.g. the output of MOSMEM). No default.
Key: vis
This is one or more input visibility datasets. The pointing
centres and primary beams corresponding to the selected
visibilities are used in the de-mosaicing process.
Key: select
Normal uv selection. See help on select. Generally you will
select only those pointings of interest.
Key: out
This gives a template name for the output images. The actual
output image names are formed by appending a number
corresponding to each pointing center to this output name. For
example, if out=cygnus, then the output images will be called
cygnus1, cygnus2, etc.
Key: imsize
This gives two values, being the output image size, in x and y.
If no value is given, then the outputs will be one primary beam
width in size. If one value is given, then this is used for both
x and y. Each output size might be smaller than this, to prevent
each output from extending beyond the edges of the input image.
Key: options
Extra processing options. There is currently only one option.
detaper This indicates that the input image is not fully
primary beam corrected. Such images are formed by
LINMOS with options=taper or by MOSMEM.
Revision: 1.10, 2021/06/02 04:45:09 UTC
Generated by miriad@atnf.csiro.au on 02 Jun 2021