View source for PPdisk simdata (CASA 3.1)

{{Simulations Intro}}
[[Category: Simulations]]

== Protoplanetary disk ==
*[ftp://ftp.cv.nrao.edu/NRAO-staff/rindebet/input50pc_672GHz.fits This fits file] is a model of a protoplanetary disk from S. Wolf (If you use it for anything more than learning CASA, please cite [http://adsabs.harvard.edu/abs/2005ApJ...619.1114W Wolf & D'Angelo 2005]).

*Simdata2 version of script: [[File:Ppdisk.simdata2.txt]]

<br>
====Explanation of the script====

=====Set simdata2 as current task and reset all parameters=====
  default("simdata2")   
=====Specify sky model image=====
  modelimage         =  "input50pc_672GHz.fits"  
=====Image coordinate system can be verified=====
  imhead("input50pc_672GHz.fits")  
=====Image center can be identified=====
  # ia.open("input50pc_672GHz.fits")
  # ia.shape()
  # [257L, 257L, 1L, 1L]
  # ia.toworld([128.5,128.5])
  # {'numeric': array([  4.71239120e+00,  -4.01423802e-01,   1.00000000e+00,  6.72000001e+11])}
  # qa.formxxx("4.71239120rad",format='hms',prec=5)
  # '18:00:00.03052'
  # qa.formxxx("-0.401423802rad",format='dms',prec=5)
  # '-022.59.59.602743'
  # ia.done()
=====Brightness scale can be viewed with 'imstat' task=====
  # imstat("input50pc_672GHz.fits")
  # ...
  #  'max': array([  6.52469971e-05]),
  # ...
  # that's 0.0652 mJy/pixel.   
=====Let's leave the brightness of the image as it is=====
  inbright           =  "unchanged"  
=====Let's call our project psim2=====
  project            =  "psim2"  
=====We'll leave the sky model the way it is -- simdata2 will create psim2.skymodel CASA image since this 
  model is a fits file, and most but not all of CASA routines can operate directly on fits=====
  modifymodel        =  False  
  skymodel           =  "input50pc_672GHz.fits"   
=====We need to decide where to point the telescope.  The image is 2/3 arcsec in size, so we only need 
  one pointing.  We could put that in a text file ourself, or let simdata2 create the ascii
  pointing file for us.===== 
  setpointings       =  True
  direction          =  "J2000 18h00m00.031s -22d59m59.6s"
  mapsize            =  "0.76arcsec"  
=====The default pointingspacing is fine - we'll only fit one pointing in the small mapsize
the default calculation maptype hexagonal is ok too since only one will fit anyway.=====
  
=====We do want to calculate visibilities in a measurement set:
let's do a 20 min snapshot observation using out20 configuration:=====
  predict            =  True
  totaltime          =  "1200s"  
=====Use appropriate antenna configurations based on desired angular resolution=====
  repodir=os.getenv("CASAPATH").split(' ')[0]
  antennalist        =  repodir+"/data/alma/simmos/alma.out20.cfg"  
=====Deconvolve the visibilities back into an image=====
  image              =  True
  vis                =  "$project.ms"
  imsize             =  [192, 192]  
=====Specify number of iteration of cleaning task with proper threshold and weighting=====
  niter              =  10000
  threshold          =  "1e-7Jy"
  weighting          =  "natural"    
=====We'd like to calculate a difference and fidelity image, and see some diagnostics:=====
  analyze            =  True  
=====And see the array but not the UV coverage:=====
  showarray          =  True
  showuv             =  False  
=====Plot both to the screen and the png files, and giving us lots of messages:=====
  graphics           =  "both"
  verbose            =  True
  overwrite = True

===To run the script, type ===

  CASA<> execfile("Ppdisk.simdata2.txt")

  CASA<> go simdata2

<br>
*Output results:


{| style="border:1px solid #3366FF; " cellspacing=2
|Input:<br> [[File:Psim2.skymodel.png|300px]]
|Predict:<br> [[File:Psim2.predict.png|300px]]
|-
|Image:<br> [[File:Psim2.image.png|300px]]
|Analyze:<br> [[File:Psim2.analysis.png|300px]]
|}