User Parameters - Mosaicking Continuum images

The linmos tool requires beam offsets to know where to place the primary beam models. Most of the time, these will be generated using the ACES footprint.py tool, and so all you need to specify are the footprint name, the position angle and pitch (separation of beams), and the frequency band you are observing in.

Note that, to use footprint.py, you will need to load the ACES module (to get the correct python packages) and have an up-to-date version of the ACES subversion repository. If you have not loaded the ACES module, it is likely the footprint.py task will fail, and mosaicking will be disabled.

It may be that you are using a non-standard arrangement that footprint.py doesnтАЩt cover. In this case you need to directly specify the LINMOS_BEAM_OFFSETS variable (this is normally set by the beamArrangements.sh script). Here is an example of how you would do this (this is for the тАЬdiamondтАЭ footprint, band 1, PA=0):

LINMOS_BEAM_OFFSETS="linmos.feeds.beam0 = [-0.000,  0.000]
linmos.feeds.beam1 = [-0.000,  1.244]
linmos.feeds.beam2 = [-1.077,  0.622]
linmos.feeds.beam3 = [-1.077, -0.622]
linmos.feeds.beam4 = [-0.000, -1.244]
linmos.feeds.beam5 = [ 1.077, -0.622]
linmos.feeds.beam6 = [ 1.077,  0.622]
linmos.feeds.beam7 = [-2.154,  0.000]
linmos.feeds.beam8 = [ 2.154, -0.000]"

Variable	Default	Parset equivalent	Description
DO_MOSAIC	true	none	Whether to mosaic the individual beam images, forming a single, primary-beam-corrected image.
BEAM_FOOTPRINT_NAME	diamond	none	The name of the beam footprint. This needs to be recognised by the ACES tool footprint.py, which generates the offsets required by the linmos application.
BEAM_FOOTPRINT_PA	0	none	The position angle of the beam footprint pattern. Passed to footprint.py.
BEAM_PITCH	1.24	none	The pitch, or beam spacing, in degrees. Passed to footprint.py.
FREQ_BAND_NUMBER	1	none	Which frequency band are we in - determines beam arrangement (1,2,3,4). Passed to footprint.py.
LINMOS_BEAM_OFFSETS	no default	feeds.beam{i} (linmos (Linear Mosaic Applicator))	Parset entries that specify the beam offsets for use by linmos. Needs to have one entry for each beam being mosaicked. See above for an example. Only provide this if running footprint.py is not going to give you what you want (eg. non-standard beam locations).
LINMOS_BEAM_SPACING	“1deg”	feeds.spacing (linmos (Linear Mosaic Applicator))	Scale factor for beam arrangement, in format like тАШ1degтАЩ. This should not be altered if you are using a standard footprint from footprint.py (ie. with BEAM_FOOTPRINT_NAME).
LINMOS_PSF_REF	0	psfref (linmos (Linear Mosaic Applicator))	Reference beam for PSF (0-based) - which beam to take the PSF information from.