0.1.67 sdtpimaging
Requires:
Synopsis SD task: do a simple calibration and imaging for total power data
Description
SD task for applying a simple baseline subtraction and do imaging for total
power data
(experimental) Task Version 2008-09-14 TT
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: | |
| calmode | | SD calibration mode (currently only support none or
baseline subtraction )
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| | | allowed: | string |
| | | Default: | none |
| masklist | | mask in data row numbers to be included for baseline
fitting for each scan
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| | | allowed: | intArray |
| | | Default: | |
| blpoly | | polynomial order for the baseline fit
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| | | allowed: | int |
| | | Default: | 1 |
| flaglist | | list of scan numbers to flag (e.g. [[1,3], 80])
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| | | allowed: | intArray |
| | | Default: | |
| antenna | | antenna name(s) or id(s)
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| | | allowed: | string |
| | | Default: | |
| stokes | | stokes or correlation name (e.g. ”I”, ”XX”)
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| | | allowed: | string |
| | | Default: | |
| createimage | | do imaging?
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| | | allowed: | bool |
| | | Default: | False |
| imagename | | output image name
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| | | allowed: | string |
| | | Default: | |
| 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 |
| 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 |
| gridfunction | | gridding function for imaging (”BOX”,”SF”,”PB”)
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| | | allowed: | string |
| | | Default: | BOX |
| plotlevel | | plot results (0=none,1+=some,¡0=hardcopy)
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| | | allowed: | int |
| | | Default: | 0 |
| |
Returns
void
Example
Keyword arguments:
sdfile -- name of input SD (MS) dataset
calmode -- calibration mode (currently only baseline subtraction)
options: ’baseline’,’none’
default: ’none’
example: choose mode ’none’ if you have
already calibrated and want to do
plotting nd/or imaging
>>> calmode=’baseline’ expandable parameters
masklist -- mask in numbers of rows from each edge of each scan to be included for baseline fitting
default: none
example: [30,30] or [30]
used first 30 rows and last 30 rows of each scan for the baseline
blpoly -- polynomial order for the baseline fit
default: 1
flaglist -- list of scan numbers to flag (ranges can be accepted)
default: [] (use all scans)
example: [[0,3],80]
flag the scan range [0,3] = [0,1,2,3] and scan 80
antenna -- select data based on antenna name(s) or id(s) in string
default: ’’ (use all antennas)
example: ’0,1’, ’DV01’
WARNING: currently baseline subtraction properly
only one of the antennas.
stokes -- select data based on stokes or polarization type
default: ’’ (use all polarizations)
example: ’XX’
createimage -- do imaging?
default: False
>>> createimage=True expandable parameters
imagename -- output image name
default: none
example: ’mySDimage.im’
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’
example: cell=[’0.2arcmin, 0.2arcmin’]
cell=’0.2arcmin’ (equivalent to example above)
phasecenter -- image phase center: direction measure or fieldid
default: 0
example: ’J2000 13h44m00 -17d02m00’, ’AZEL -123d48m29 15d41m41’
ephemsrcname -- ephemeris source name to proper shifting to center on the moving source
for imaging
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’
gridfunction -- gridding function for imaging
options: ’BOX’ (Box-car), ’SF’ (Spheroidal), ’PB’ (Primary-beam)
default: ’BOX’
example: ’SF’
plotlevel -- control for plotting of results
options: (int) 0=none, 1=some, 2=more, <0=hardcopy
default: 0 (no plotting)
example: plotlevel<0 as abs(plotlevel), e.g.
-1: hardcopy plot (will be named <sdfile>_scans.eps)
1: plot raw data, calibrated data (for calmode=’baseline)
plot raw or if exist calibrated data (for calmode=’none’)
2: plot raw data, progressively display baseline fitting for each scan,
and final calibrated data (for calmode=’baseline’)
DESCRIPTION:
Task sdtpimaging performs data selection, calibration, and imaging for single-dish
totalpower raster scan data. This is a still experimental task made to work
mostly for the data taken at the ALMA Testing Facility (ATF) or OSF. 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. By setting calmode=’none’, one can run sdtpimaging to
plot the data (raw or calibrated, if exists) and further imaging by setting createimage=True.
The calibration available at this moment is just a simple baseline subtraction for
each scan. The fitted regions set by masklist are the common for all the scans.
Selection of the antennas can be made by setting antennaid(s) or antenna name(s)
in string (e.g. ’0’, ’0,1’, ’DV01’,etc.).
For baseline subtraction, it currently works properly for a single antenna selection.
So a separate sdtpimaging task needs to be ran for each antenna.
It currently assumes that the data has a single spw(=0) and fieldid(=0).
By setting flaglist, one can set flag by scan numbers to be excluded from imaging.
(Note: ’scan numbers’ are determined from state id and related to SUB_SCAN column in STATE
subtable and not to SCAN_NUMBER in MS.)
The selection of polarizations can be made by specify the polarization name in stokes,
such as ’XX’ or ’YY’ for linear polarizations. For example, with createimage=True,
stokes=’XXYY’ will produces an image cube with each plane contains image of one of i
the polarizations while stokes=’’ or stokes=’I’ will produces a ’total intensity’ or Stokes I image.
Among the imaging sub-parameters, ephemsrcname is used to set to a name of the moving source
such as planets to produce a stationary image (can be omitted), and pointingcolumn is
used to specify which pointing data column to use for imaging.
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.