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newsimulator - Constructor

	Package	synthesis
	Module	newsimulator
	Tool	newsimulator

Construct a newsimulator tool

Synopsis
newsimulator(ms)

Description
This is used to construct newsimulator tools. A newsimulator tool can either be instantiated from an existing MeasurementSet, predicting and/or corrupting data on the given coordinates, or it can be used to create a fundamentally new MeasurementSet from descriptions of the array configuration and the observational parameters. This is useful for making a newsimulator tool which will make a MeasurementSet from scratch. In order to do this, you must also run setconfig, setfield, setspwindow, setfeed, and settimes. Creating the actual MS is performed by observe. Data can be predict-ed and then corrupted-ed. In this example, we read in the antenna coordinates from an ASCII file:

Arguments

ms		MeasurementSet to be created
		Allowed:	Table name
		Default:	'MS'

Returns
newsimulator tool

Example

  tabname := 'VLAC.LOCAL.TAB';  asciifile := 'VLAC.LOCAL.STN'
  mytab := tablefromascii(tabname, asciifile);
  xx:=[]; yy:=[]; zz:=[]; diam:=[];
  xx := mytab.getcol('X');  
  yy := mytab.getcol('Y');
  zz := mytab.getcol('Z');
  diam := mytab.getcol('DIAM');
#
  mysim := newsimulator('NEW1.ms');
# do configuration
  posvla := dm.observatory('vla');  #  dm.observatory('ALMA') also works!
  mysim.setconfig(telescopename='VLA', x=xx, y=yy, z=zz, dishdiameter=diam, 
	        mount='alt-az', antname='VLA',
                coordsystem='local', referencelocation=posvla);

# Initialize the spectral windows    
  mysim.setspwindow(spwname='CBand', freq='5GHz',
		    deltafreq='50MHz',
		    freqresolution='50MHz',
		    nchannels=1,
		    stokes='RR RL LR LL');
  mysim.setspwindow(spwname='LBand', freq='1.420GHz',
		    deltafreq='3.2MHz',
		    freqresolution='3.2MHz',
		    nchannels=32,
		    stokes='RR LL');
  
  
# Initialize the source and calibrater
  mysim.setfield(sourcename='My cal',
		 sourcedirection=dm.direction('J2000','00h0m0.0','+45.0.0.000'),
		 calcode='A');
  mysim.setfield(sourcename='My source',
		 sourcedirection=dm.direction('J2000','01h0m0.0','+47.0.0.000'));
  
  mysim.setlimits(shadowlimit=0.001, elevationlimit='8.0deg');
  mysim.setauto(autocorrwt=0.0);

  mysim.settimes(integrationtime='10s', usehourangle=F, referencetime=dm.epoch('utc', 'today'));

  mysim.observe('My cal', 'LBand', starttime='0s', stoptime='300s');
  mysim.observe('My source', 'LBand', starttime='310s', stoptime='720s');
  mysim.observe('My cal', 'CBand', starttime='720s', stoptime='1020s');
  mysim.observe('My source', 'CBand', starttime='1030s', stoptime='1500s');

  mysim.setdata(spwid=1, fieldid=1);
  mysim.predict(modelimage='M31.MOD');
  mysim.setdata(spwid=2, fieldid=2);
  mysim.predict(modelimage='BigLBand.MOD');
  mysim.close();