0.1.59 sdimaging
Requires:
Synopsis SD task: imaging for total power and spectral data
Description
SD task for imaging both total power and spectral data
Task Version 2009-07-08 TN
Arguments
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| Inputs | |
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| sdfile | | name of input SD dataset(only MS is allowed for this
task)
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| | | allowed: | string |
| | | Default: | |
| specunit | | units for spectral axis (channel,km/s,GHz)
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| | | allowed: | string |
| | | Default: | channel |
| restfreq | | rest frequency
|
| | | allowed: | any |
| | | Default: | variant |
| scanlist | | list of scans to use (e.g. [1,2,3,4])
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| | | allowed: | intArray |
| | | Default: | |
| field | | string for selection by source name
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| | | allowed: | any |
| | | Default: | variant 0 |
| spw | | spectral window id for imaging
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| | | allowed: | int |
| | | Default: | 0 |
| antenna | | antenna name(s) or id(s)
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| | | allowed: | any |
| | | Default: | variant 0 |
| stokes | | stokes or correlation name (e.g. ”I”, ”XX”)
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| | | allowed: | string |
| | | Default: | |
| gridfunction | | gridding function for imaging (”BOX”,”SF”,”PB”)
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| | | allowed: | string |
| | | Default: | BOX |
| imagename | | output image name
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| | | allowed: | string |
| | | Default: | |
| overwrite | | overwrite option
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| | | allowed: | bool |
| | | Default: | False |
| imsize | | x and y image size in pixels, symmetric for single value
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| | | allowed: | intArray |
| | | Default: | 256 256 |
| cell | arcmin | x and y cell size. default unit arcmin
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| | | allowed: | doubleArrayarcmin |
| | | Default: | 1.01.0 |
| dochannelmap | | True for channel map, False for total power imaging
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| | | allowed: | bool |
| | | Default: | False |
| nchan | | number of spectral channel for created image
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| | | allowed: | int |
| | | Default: | 1 |
| start | | reference value of start channel (in units of specunit)
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| | | allowed: | double |
| | | Default: | 0 |
| step | | width of each spectral channel (in units of specunit)
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| | | allowed: | double |
| | | Default: | 1 |
| phasecenter | | Image phase center: position or field index
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| | | allowed: | any |
| | | Default: | variant |
| ephemsrcname | | ephemeris source name
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| | | allowed: | string |
| | | Default: | |
| pointingcolumn | | pointing data column to use
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| | | allowed: | string |
| | | Default: | direction |
| |
Returns
void
Example
Keyword arguments:
sdfile -- name of input SD (MS) dataset
specunit -- units for spectral axis
options: (str) ’channel’,’km/s’,’GHz’,’MHz’,’kHz’,’Hz’
default: ’channel’
example: this will be the units for nchan, start, and step
>>> specunit=’km/s’ expandable parameters
restfreq -- rest frequency
default: ’’ (refer input data)
example: 1.0e11, ’100GHz’
scanlist -- list of scan numbers to process
default: [] (use all scans)
example: [21,22,23,24]
this selection is in addition to field and spw
field -- field id or selection string for selecting scans by name
default: 0
example: ’FLS3a’, 0
this selection is in addition to scanlist and spw
spw -- spectral window id
default: 0
example: 1
this selection is in addition to scanlist and field
antenna -- select data based on antenna name(s) or id(s)
default: 0
example: ’0’, ’DV01’
stokes -- select data based on stokes or polarization type
default: ’’ (use all polarizations)
example: ’XX’
gridfunction -- gridding function for imaging
options: ’BOX’ (Box-car), ’SF’ (Spheroidal), ’PB’ (Primary-beam)
default: ’BOX’
example: ’SF’
imagename -- output image name
default: none
example: ’mySDimage.im’
overwrite -- overwrite option for imagename
default: False (not overwrite)
options: True, False
example: if True, existing file will be overwritten
imsize -- x and y image size in pixels, symmetric for single value
default: [256,256]
example: imsize=200 (equivalent to [200,200])
cell -- x and y cell size. default unit arcmin
default: [’1.0arcmin’, ’1.0arcmin’]
example: cell=[’0.2arcmin, 0.2arcmin’]
cell=’0.2arcmin’ (equivalent to example above)
dochannelmap -- channel map image or total power image
default: False (total power)
options: True (channel map), False
>>> dochannelmap=True expandable parameters
nchan -- number of spectral channel for created image
default: 1
example: to do total power imaging, set -1
start -- reference value of start channel (in units of specunit)
default: 0 (0th channel if specunit=’channel’)
example: 100
step -- width of each spectral channel for created image
default: 1 (channel width of 1 channel if specunit=’channel’)
aexample: 100
phasecenter -- image phase center: direction measure or fieldid
default: 0
example: ’J2000 13h44m00 -17d02m00’, ’AZEL -123d48m29 15d41m41’
ephemsrcname -- ephemeris source name for moving source
default: ’’
if the source name in the data matches one of the known
solar objects by the system, this task automatically set
the source name.
example: ’moon’
pointingcolumn -- pointing data column to use
option: ’direction’, ’target’, ’pointing_offset’, ’source_offset’, ’encoder’
default: ’direction’
DESCRIPTION:
Task sdimaging create image from input single-dish data.
The input can be either total power and spectral data. Currently,
this task directly accesses the Measurement Set data only because of
the data access efficiency. So it differs from other single-dish tasks
that mostly operate on the ASAP scantable data format.
Units of spectral axis can be specified via a parameter specunit.
Allowed values for specunit are ’channel’, ’GHz’, ’MHz’, ’kHz’, ’Hz’,
and ’km/s’. This parameter is also used as the units of the parameter
start and step that specify reference value of start channel and width
of each spectral channel for channel map, respectively.
Selection of the antennas can be made by setting antennaid(s) or
antenna name(s) in string (e.g. ’0’, ’DV01’,etc.). Note that the task
doesn’t work for multiple antenna selection and/or multiple field
selection.
The parameter gridfunction sets gridding function for imaging.
Currently, the task supports ’BOX’ (Box-car), ’SF’ (Prolate Spheroidal
Wave Function), and ’PB’ (Primary Beam). For ’PB’, correct antenna
informations should be included in input file.
Please send any comments or questions about CASA or AIPS++
to aips2-requests@nrao.edu
Copyright © 2008 Associated Universities Inc.,
Washington, D.C.
This code is available under the terms of the GNU General Public Lincense
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Updated daily during alpha development.