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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





Inputs

sdfile

name of input SD dataset(only MS is allowed for this task)

allowed:

string

Default:

specunit

units for spectral axis (channel,km/s,GHz)

allowed:

string

Default:

channel

restfreq

rest frequency

allowed:

any

Default:

variant

scanlist

list of scans to use (e.g. [1,2,3,4])

allowed:

intArray

Default:

field

string for selection by source name

allowed:

any

Default:

variant 0

spw

spectral window id for imaging

allowed:

int

Default:

0

antenna

antenna name(s) or id(s)

allowed:

any

Default:

variant 0

stokes

stokes or correlation name (e.g. ”I”, ”XX”)

allowed:

string

Default:

gridfunction

gridding function for imaging (”BOX”,”SF”,”PB”)

allowed:

string

Default:

BOX

imagename

output image name

allowed:

string

Default:

overwrite

overwrite option

allowed:

bool

Default:

False

imsize

x and y image size in pixels, symmetric for single value

allowed:

intArray

Default:

256 256

cell

arcmin

x and y cell size. default unit arcmin

allowed:

doubleArrayarcmin

Default:

1.01.0

dochannelmap

True for channel map, False for total power imaging

allowed:

bool

Default:

False

nchan

number of spectral channel for created image

allowed:

int

Default:

1

start

reference value of start channel (in units of specunit)

allowed:

double

Default:

0

step

width of each spectral channel (in units of specunit)

allowed:

double

Default:

1

phasecenter

Image phase center: position or field index

allowed:

any

Default:

variant

ephemsrcname

ephemeris source name

allowed:

string

Default:

pointingcolumn

pointing data column to use

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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