def test_componentlist(self):
srclist = [
(SkyCoord(10 * u.deg, 5 * u.deg), 1.5 * u.mJy, 3 * u.GHz),
(SkyCoord(10 * u.deg, 5.1 * u.deg), 15 * u.mJy, 2.5 * u.GHz),
]
out_path = os.path.join(self.output_dir, "foo.cl")
script = []
sim.make_componentlist(script, srclist, out_path)
# Need to insert these prior to `cl.close()`
script.insert(-1, "print cl.length()")
script.insert(-1, "print cl.getcomponent(0)")
self.casa.run_script(script)
out, err = self.casa.run_script([])
self.assertTrue(os.path.isdir(out_path))
def test_componentlist(self):
srclist = [
(SkyCoord(10 * u.deg, 5 * u.deg), 1.5 * u.mJy, 3 * u.GHz,),
(SkyCoord(10 * u.deg, 5.1 * u.deg), 15 * u.mJy, 2.5 * u.GHz,),
]
out_path = os.path.join(self.output_dir, "foo.cl")
script = []
sim.make_componentlist(script, srclist, out_path)
# Need to insert these prior to `cl.close()`
script.insert(-1, 'print cl.length()')
script.insert(-1, 'print cl.getcomponent(0)')
self.casa.run_script(script)
out, err = self.casa.run_script([])
self.assertTrue(os.path.isdir(out_path))
def simulate_vis_with_casa(pointing_centre, source_list, output_dir):
"""
Use casapy to simulate a visibility measurementset with noise.
(This also produces an initial set of UVW data)
Args:
pointing_centre (:class:`astropy.coordinates.SkyCoord`)
source_list: list of :class:`fastimgproto.skymodel.helpers.SkySource`
output_dir (str): Output directory which will contain `vis.ms`
Returns (str): Full path to `vis.ms`.
"""
ensure_dir(output_dir)
commands_logfile = os.path.join(
output_dir, "./casa-visibilities_for_point_source-commands.log")
component_list_path = os.path.join(output_dir, './sources.cl')
output_visibility = os.path.abspath(os.path.join(output_dir, './vis.ms'))
if os.path.isfile(commands_logfile):
os.unlink(commands_logfile)
casa = drivecasa.Casapy(commands_logfile=commands_logfile)
script = []
# For VLA reference numbers, see:
# https://science.nrao.edu/facilities/vla/docs/manuals/oss/performance/fov
# https://science.nrao.edu/facilities/vla/docs/manuals/oss/performance/resolution
# Define some observation parameters:
obs_central_frequency = 3. * u.GHz
obs_frequency_bandwidth = 0.125 * u.GHz
primary_beam_fwhm = (45. * u.GHz / obs_central_frequency) * u.arcmin
# Convert the sources to a CASA 'componentlist'
component_list_path = sim.make_componentlist(
script,
source_list=[(s.position, s.flux, s.frequency) for s in source_list],
out_path=component_list_path)
# Open the visibility file
sim.open_sim(script, output_visibility)
# Configure the virtual telescope
# sim.setpb(script,
# telescope_name='VLA',
# primary_beam_hwhm=primary_beam_fwhm * 0.5,
# frequency=obs_central_frequency)
sim.setconfig(script,
telescope_name='VLA',
antennalist_path=vla_c_antennalist_path)
sim.setspwindow(
script,
freq_start=obs_central_frequency - 0.5 * obs_frequency_bandwidth,
freq_resolution=obs_frequency_bandwidth,
freq_delta=obs_frequency_bandwidth,
n_channels=1,
)
sim.setfeed(script, )
sim.setfield(script, pointing_centre)
sim.setlimits(script)
sim.setauto(script)
ref_time = Time('2014-05-01T19:55:45', format='isot', scale='tai')
sim.settimes(script, integration_time=10 * u.s, reference_time=ref_time)
# Generate the visibilities
sim.observe(script, stop_delay=10 * u.s)
sim.predict(script, component_list_path)
sim.set_simplenoise(script, noise_std_dev=1 * u.mJy)
sim.corrupt(script)
sim.close_sim(script)
casa.run_script(script)
return output_visibility
obs_frequency_bandwidth = 0.125 * u.GHz
primary_beam_fwhm = (45. * u.GHz / obs_central_frequency) * u.arcmin
# Define the field centre and sources:
centre_ra = 180 * u.deg
centre_dec = 34 * u.deg
# Sources are represented by tuples of (posn, flux, freq)
pointing_centre = SkyCoord(centre_ra, centre_dec)
srclist = [
(SkyCoord(centre_ra, centre_dec), 1. * u.mJy, obs_central_frequency),
(SkyCoord(centre_ra, centre_dec + primary_beam_fwhm * 0.5), 1. * u.mJy,
obs_central_frequency),
]
# Convert the sources to a CASA 'componentlist'
component_list_path = sim.make_componentlist(script, srclist,
component_list_path)
# Open the visibility file
sim.open_sim(script, output_visibility)
# Configure the virtual telescope
sim.setpb(script,
telescope_name='VLA',
primary_beam_hwhm=primary_beam_fwhm * 0.5,
frequency=obs_central_frequency)
sim.setconfig(script, telescope_name='VLA', antennalist_path='./vla.c.cfg')
sim.setspwindow(
script,
freq_start=obs_central_frequency - 0.5 * obs_frequency_bandwidth,
freq_resolution=obs_frequency_bandwidth,
freq_delta=obs_frequency_bandwidth,
obs_frequency_bandwidth = 0.125 * u.GHz
primary_beam_fwhm = (45. * u.GHz / obs_central_frequency) * u.arcmin
# Define the field centre and sources:
centre_ra = 180 * u.deg
centre_dec = 34 * u.deg
# Sources are represented by tuples of (posn, flux, freq)
pointing_centre = SkyCoord(centre_ra, centre_dec)
srclist = [
(SkyCoord(centre_ra, centre_dec), 1. * u.mJy, obs_central_frequency),
(SkyCoord(centre_ra, centre_dec + primary_beam_fwhm * 0.5), 1. * u.mJy,
obs_central_frequency),
]
# Convert the sources to a CASA 'componentlist'
component_list_path = sim.make_componentlist(script, srclist,
component_list_path)
# Open the visibility file
sim.open_sim(script, output_visibility)
# Configure the virtual telescope
sim.setpb(script,
telescope_name='VLA',
primary_beam_hwhm=primary_beam_fwhm * 0.5,
frequency=obs_central_frequency)
sim.setconfig(script,
telescope_name='VLA',
antennalist_path='./vla.c.cfg')
sim.setspwindow(script,
freq_start=obs_central_frequency - 0.5 * obs_frequency_bandwidth,
freq_resolution=obs_frequency_bandwidth,
def simulate_vis_with_casa(pointing_centre,
source_list,
noise_std_dev,
vis_path,
overwrite=True,
echo=False):
"""
Use casapy to simulate a visibility measurementset with noise.
(This also produces an initial set of UVW data)
Args:
pointing_centre (:class:`astropy.coordinates.SkyCoord`)
source_list: list of :class:`fastimgproto.skymodel.helpers.SkySource`
noise_std_dev (astropy.units.Quantity): Standard deviation of the noise
(units of Jy).
vis_path (str): Path to visibilities generated.
echo (bool): Echo the CASA output to terminal during processing.
Returns (str): Full path to `vis.ms`.
"""
vis_abspath = os.path.abspath(vis_path)
commands_logfile = vis_abspath + "_casa_commands.log"
casa_logfile = vis_abspath + "_casa_log.log"
component_list_path = vis_abspath + "_sources.cl"
for outdir in vis_abspath, component_list_path:
if os.path.isdir(outdir):
if overwrite:
shutil.rmtree(outdir)
else:
raise IOError(
"{} already present and overwrite==False.".format(outdir))
if os.path.isfile(commands_logfile):
os.remove(commands_logfile)
ensure_dir(os.path.dirname(vis_abspath))
casa = drivecasa.Casapy(commands_logfile=commands_logfile,
casa_logfile=casa_logfile,
echo_to_stdout=echo)
script = []
# Add subroutine definition, for manual reproduction with CASA:
script.append(
drivecasa.drivecasa.commands.subroutines.def_load_antennalist)
# Define some observation parameters...
# For VLA reference numbers, see:
# https://science.nrao.edu/facilities/vla/docs/manuals/oss/performance/fov
# https://science.nrao.edu/facilities/vla/docs/manuals/oss/performance/resolution
obs_central_frequency = 3. * u.GHz
obs_frequency_bandwidth = 0.125 * u.GHz
primary_beam_fwhm = (45. * u.GHz / obs_central_frequency) * u.arcmin
# Convert the sources to a CASA 'componentlist'
component_list_path = sim.make_componentlist(
script,
source_list=[(s.position, s.flux, s.frequency) for s in source_list],
out_path=component_list_path)
# Open the visibility file
sim.open_sim(script, vis_abspath)
# Configure the virtual telescope
# sim.setpb(script,
# telescope_name='VLA',
# primary_beam_hwhm=primary_beam_fwhm * 0.5,
# frequency=obs_central_frequency)
sim.setconfig(script,
telescope_name='VLA',
antennalist_path=vla_c_antennalist_path)
sim.setspwindow(
script,
freq_start=obs_central_frequency - 0.5 * obs_frequency_bandwidth,
freq_resolution=obs_frequency_bandwidth,
freq_delta=obs_frequency_bandwidth,
n_channels=1,
)
sim.setfeed(script, )
sim.setfield(script, pointing_centre)
sim.setlimits(script)
sim.setauto(script)
ref_time = Time('2014-05-01T19:55:45', format='isot', scale='tai')
sim.settimes(script, integration_time=10 * u.s, reference_time=ref_time)
# Generate the visibilities
sim.observe(script, stop_delay=10 * u.s)
sim.predict(script, component_list_path)
sim.set_simplenoise(script, noise_std_dev=noise_std_dev)
sim.corrupt(script)
sim.close_sim(script)
casa_output = casa.run_script(script)
return casa_output
def simulate_vis_with_casa(pointing_centre, source_list, noise_std_dev, vis_path,
overwrite=True, echo=False):
"""
Use casapy to simulate a visibility measurementset with noise.
(This also produces an initial set of UVW data)
Args:
pointing_centre (:class:`astropy.coordinates.SkyCoord`)
source_list: list of :class:`fastimgproto.skymodel.helpers.SkySource`
noise_std_dev (astropy.units.Quantity): Standard deviation of the noise
(units of Jy).
vis_path (str): Path to visibilities generated.
echo (bool): Echo the CASA output to terminal during processing.
Returns (str): Full path to `vis.ms`.
"""
vis_abspath = os.path.abspath(vis_path)
commands_logfile = vis_abspath + "_casa_commands.log"
casa_logfile = vis_abspath + "_casa_log.log"
component_list_path = vis_abspath + "_sources.cl"
for outdir in vis_abspath, component_list_path:
if os.path.isdir(outdir):
if overwrite:
shutil.rmtree(outdir)
else:
raise IOError("{} already present and overwrite==False.".format(
outdir
))
if os.path.isfile(commands_logfile):
os.remove(commands_logfile)
ensure_dir(os.path.dirname(vis_abspath))
casa = drivecasa.Casapy(commands_logfile=commands_logfile,
casa_logfile=casa_logfile,
echo_to_stdout=echo)
script = []
# Add subroutine definition, for manual reproduction with CASA:
script.append(drivecasa.drivecasa.commands.subroutines.def_load_antennalist)
# Define some observation parameters...
# For VLA reference numbers, see:
# https://science.nrao.edu/facilities/vla/docs/manuals/oss/performance/fov
# https://science.nrao.edu/facilities/vla/docs/manuals/oss/performance/resolution
obs_central_frequency = 3. * u.GHz
obs_frequency_bandwidth = 0.125 * u.GHz
primary_beam_fwhm = (45. * u.GHz / obs_central_frequency) * u.arcmin
# Convert the sources to a CASA 'componentlist'
component_list_path = sim.make_componentlist(
script,
source_list=[(s.position, s.flux, s.frequency) for s in source_list],
out_path=component_list_path)
# Open the visibility file
sim.open_sim(script, vis_abspath)
# Configure the virtual telescope
# sim.setpb(script,
# telescope_name='VLA',
# primary_beam_hwhm=primary_beam_fwhm * 0.5,
# frequency=obs_central_frequency)
sim.setconfig(script,
telescope_name='VLA',
antennalist_path=vla_c_antennalist_path)
sim.setspwindow(script,
freq_start=obs_central_frequency - 0.5 * obs_frequency_bandwidth,
freq_resolution=obs_frequency_bandwidth,
freq_delta=obs_frequency_bandwidth,
n_channels=1,
)
sim.setfeed(script, )
sim.setfield(script, pointing_centre)
sim.setlimits(script)
sim.setauto(script)
ref_time = Time('2014-05-01T19:55:45', format='isot', scale='tai')
sim.settimes(script, integration_time=10 * u.s, reference_time=ref_time)
# Generate the visibilities
sim.observe(script, stop_delay=10 * u.s)
sim.predict(script, component_list_path)
sim.set_simplenoise(script, noise_std_dev=noise_std_dev)
sim.corrupt(script)
sim.close_sim(script)
casa_output = casa.run_script(script)
return casa_output