Examples

Set flux density explictly

With standard='manual' (and selectdata=True), the parameters look like this. fluxdensity takes a list of flux densities, [I, Q, U, V] at reffreq. The same reffreq will be used as a reference frequecy for spix, polindex, and polange.

#  setjy :: Fills the model column with the visibilities of a calibrator
vis                 =         ''        #  Name of input visibility file
field               =         ''        #  Field name(s)
spw                 =         ''        #  Spectral window identifier (list)
selectdata          =       True        #  Other data selection parameters
     timerange      =         ''        #  Time range to operate on (for usescratch=T)
     scan           =         ''        #  Scan number range (for usescaratch=T)
     intent         =         ''        #  Observation intent
     observation    =         ''        #  Observation ID range (for usescratch=T)

scalebychan         =       True        #  scale the flux density on a per channel basis or else on
                                        #   a per spw basis
standard            =   'manual'        #  Flux density standard
     fluxdensity    =         -1        #  Specified flux density [I,Q,U,V]; (-1 will lookup values)
     spix           =        0.0        #  Spectral index (including higher terms) of I fluxdensity
     reffreq        =     '1GHz'        #  Reference frequency for spix
     polindex       =         []        #  Coefficients of an expansion of frequency-dependent
                                        #   linear polarization fraction expression
     polangle       =         []        #  Coefficients of an expansion of frequency-dependent
                                        #   polarization angle expression
     rotmeas        =        0.0        #  Rotation measure (in rad/m^2)

usescratch          =      False        #  Will create if necessary and use the MODEL_DATA

In the simplest form, setting a constant Stokes I flux density for a calibrator ( field='0') for all spw can be done as

setjy(vis='data.ms', field='0', fluxdensity=[3.5,0.0,0.0,0.0])

To set Stokes I flux density with spectral index and Stokes Q and U using frequency-dependent polarization index and polarization angle (in rad) also including rotation measure:

setjy(vis=‘data.ms’, standard='manual', field = ‘3C48’, fluxdensity=[6.4861, 0, 0, 0], spix=[-0.630458,-0.132252], reffreq="3000.0MHz”, polindex=[0.02143,0.0392,0.002349,-0.0230] polangle=[-1.7233,1.569,-2.282,1.49], rotmeas=-68.0)

Use one of the predefined standards

 Current default for standard is 'Perley-Butler 2013' and the parameters look like this (with selectdata=True):

#  setjy :: Fills the model column with the visibilities of a calibrator
vis                 =         ''        #  Name of input visibility file
field               =         ''        #  Field name(s)
spw                 =         ''        #  Spectral window identifier (list)
selectdata          =       True        #  Other data selection parameters
     timerange      =         ''        #  Time range to operate on (for usescratch=T)
     scan           =         ''        #  Scan number range (for usescaratch=T)
     intent         =         ''        #  Observation intent
     observation    =         ''        #  Observation ID range (for usescratch=T)

scalebychan         =       True        #  scale the flux density on a per channel basis or else on a per spw basis
standard            = 'Perley-Butler 2013' #  Flux density standard
     model          =         ''        #  File location for field model
     listmodels     =      False        #  List the available modimages for VLA calibrators or Tb models for Solar System objects
     interpolation  =  'nearest'        #  method to be used to interpolate in time

usescratch          =      False        #  Will create if necessary and use the MODEL_DATA

In the most simplest case, using the default stanadard, if field='0' is one of the known sources as listed in Flux Calibrator Models (e.g. 3C286), the following will set appropriate channel dependent flux densities for all spws.

setjy(vis='data.ms', field='0')

For selected spws with field specified by the source name:

setjy(vis='data.ms', field='3C286', spw='0,2')

With a model image:

setjy(vis='ngc7538_XBAND.ms', field='0', modimage='3C48_X.im')

Note that if there is no 3C48_X.im in the current directory, setjy looks for it in the default model data image directory.

 An example for a Solar System object as a flux calibrator using using data from the M99 tutorial in CASA Guides:

setjy(vis=’c0104I’, field=’MARS’, spw=’0~2’, standard=’Butler-JPL-Horizons 2012’)

To list supported models for the relevant standard, set listmodels=True and select standard (no need to set vis):

setjy(listmodels=True)

This will show a list of the VLA model images along with their full paths to the terminal:

No candidate modimages matching '*.im* *.mod*' found in .

Candidate modimages (*) in /users/ttsutsum/casabuilds/data/nrao/VLA/CalModels:
3C138_A.im 3C138_L.im 3C138_U.im 3C147_C.im 3C147_Q.im 3C147_X.im 3C286_K.im 3C286_S.im 3C48_A.im  3C48_L.im  3C48_U.im
3C138_C.im 3C138_Q.im 3C138_X.im 3C147_K.im 3C147_S.im 3C286_A.im 3C286_L.im 3C286_U.im 3C48_C.im  3C48_Q.im  3C48_X.im
3C138_K.im 3C138_S.im 3C147_A.im 3C147_L.im 3C147_U.im 3C286_C.im 3C286_Q.im 3C286_X.im 3C48_K.im  3C48_S.im  README

Similarly, for Solar System objects (e.g. standard='Butler-JPL-Horizons 2012'), Tb models and new time asteroid models are listed by:

setjy(standard='Butler-JPL-Horizons 2012', listmodels=True)

This will show a list looks like below in the terminal:

Tb models of solar system objects available for Butler-JPL-Horizons 2012 (*Tb*.dat) in /users/ttsutsum/casabuilds/data/alma/SolarSystemModels:
Callisto_Tb.dat  Europa_Tb.dat    Io_Tb.dat        Jupiter_Tb.dat   Mars_Tb_time.dat Pallas_Tb.dat    Uranus_Tb.dat    Vesta_Tb.dat
Ceres_Tb.dat     Ganymede_Tb.dat  Juno_Tb.dat      Mars_Tb.dat      Neptune_Tb.dat   Titan_Tb.dat     Venus_Tb.dat

Time variable models of asteroids available for Butler-JPL-Horizons 2012 [only applicable for the observation date 2015.01.01 0UT and beyond] (*fd_time.dat) in /users/ttsutsum/casabuilds/data/alma/SolarSystemModels:
Ceres_fd_time.dat   Lutetia_fd_time.dat Pallas_fd_time.dat  Vesta_fd_time.dat