Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.mrao.cam.ac.uk/~bn204/alma/memo-turb/bnalmasim.py Дата изменения: Fri Aug 10 20:17:35 2012 Дата индексирования: Tue Oct 2 10:30:04 2012 Кодировка:

# Bojan Nikolic ,
# October 2007
#
# Try to simplify some of the alma simulator code

import numpy
from itertools import izip

from almaconfparse import *

def ExportUVFits(fnamein,
fnameout):

"Wrap the casa command of the same name"

if os.access(fnameout, os.F_OK ) :
os.remove(fnameout)

default(exportuvfits)
exportuvfits(fnamein, fnameout)



def SetupSM(smi,
antennalist ,
startfreq,
chanwidth,
nchan,
**kwargs):

"Setup an instance of the casa simulator tool to simple configuration"

"""
antennalist: filename that contains the antenna poistions
startfreq : start frequency of the only spectral window
"""

x, y, z, d, names = AntennaFileToLists( antennalist)

posalma=me.observatory('ALMA')
smi.setconfig(telescopename='ALMA',
x=x.tolist(),
y=y.tolist(),
z=z.tolist(),
dishdiameter=d.tolist(),
mount=['alt-az'],
antname=names,
coordsystem='local',
referencelocation=posalma);

smi.setspwindow(spwname="simband",
freq= "%fGHz" % startfreq,
deltafreq="%fGHz" % chanwidth,
freqresolution="%fGHz" % chanwidth,
nchannels=nchan,
stokes='XX YY');

smi.setfeed(mode='perfect X Y',
pol=['']);

smi.setlimits(shadowlimit=0.01,
elevationlimit='10deg');

# NO autocorrelations
smi.setauto(0.0);

def Simulate(project,
complist,
antennalist,
startfreq,
chanwidth,
nchan,
direction,
integrationtime,
observationtime,
refdate="2008/06/21/03:25:00",
export=True,
**kwargs):
"""
All frequencies are in gigaherz
direction is a string
"""

msfile=project+'.ms'

sm.open(msfile)

SetupSM( sm,
antennalist,
startfreq,
chanwidth,
nchan)

sm.setfield(sourcename="SimField",
sourcedirection=direction)

reftime = me.epoch('TAI', refdate);
sm.settimes(integrationtime="%fs" % integrationtime,
usehourangle=True,
referencetime=reftime)

# Actually getting to observation
sm.observe(sourcename="SimField",
spwname="simband",
starttime="0s",
stoptime="%fs"%observationtime)

sm.setdata(fieldid=[0])
sm.setvp()
sm.predict(imagename=[""], complist=complist)
sm.close()
sm.done()

if export:
default(exportuvfits)
exportuvfits(msfile, msfile+".fits")





def SimulateSwitched(project,
complist_fname,
directionl,
obstimel ,
integrationtime,
obsstart,
conf = None):

"Simulate a switched set of observations"

"""
obsstart is time of the start of observation

conf is the alma configuration
"""

msfile=project+'.ms'
sm.open(msfile)

# To begin with set up with defaults
SetupSM( sm,
antennalist=Conf(conf),
startfreq=300,
chanwidth=8,
nchan=1)

reftime = me.epoch('TAI', obsstart);
sm.settimes(integrationtime="%fs" % integrationtime,
usehourangle=False,
referencetime=reftime)

runtime = 0
for fi , (direction, obstime) in enumerate(izip( directionl, obstimel )):

print fi , (direction, obstime)

cfname = ( "F%i" % fi)

if ( (fi % 2) == 0):
sm.setfield(sourcename=cfname,
sourcedirection=direction,
calcode="C")
else:
sm.setfield(sourcename=cfname,
sourcedirection=direction,)


sm.observe(sourcename=cfname,
spwname="simband",
starttime="%fs" % runtime,
stoptime="%fs"% (runtime+obstime) )
runtime += obstime

sm.setdata(fieldid=[fi])
sm.setvp()
sm.predict(imagename=[""], complist=complist_fname)

sm.close()
sm.done()

ExportUVFits(msfile, msfile+".fits")


def SimulateSwitchedV2(project,
complist_fname,
directionl,
obstimel ,
integrationtime,
obsstart,
cycles=1,
conf = None):

"Simulate a switched set of observations"

"""
In this version only two sources are possible, calibrator and
target.

so directionl and obstimel must be lists with two elements

obsstart is time of the start of observation

conf is the alma configuration
"""

msfile=project+'.ms'
sm.open(msfile)

# To begin with set up with defaults
SetupSM( sm,
antennalist=Conf(conf),
startfreq=300,
chanwidth=8,
nchan=1)

reftime = me.epoch('TAI', obsstart);
sm.settimes(integrationtime="%fs" % integrationtime,
usehourangle=False,
referencetime=reftime)

runtime = 0
for cno in range(cycles):

fi = cno % 2
direction= directionl[fi]
obstime = obstimel[fi]

cfname = ( "F%i" % fi)

if (fi == 0):
sm.setfield(sourcename=cfname,
sourcedirection=direction,
calcode="C")
else:
sm.setfield(sourcename=cfname,
sourcedirection=direction,)


sm.observe(sourcename=cfname,
spwname="simband",
starttime="%fs" % runtime,
stoptime="%fs"% (runtime+obstime) )
runtime += obstime

sm.setdata(fieldid=[fi])
sm.setvp()
sm.predict(imagename=[""], complist=complist_fname)

sm.close()
sm.done()

ExportUVFits(msfile, msfile+".fits")