else:
lst = 0.5 * (lst_edges_left + lst_edges_right)
t_snap = (lst_edges_right - lst_edges_left) / 15.0 * 3.6e3
else:
t_snap = 112.0 + NP.zeros(
n_snaps) # in seconds (needs to be generalized)
lst = lst_wrapped + 0.5 * t_snap / 3.6e3 * 15.0
# pointings_dircos_orig = GEOM.altaz2dircos(pointings_altaz_orig, units='degrees')
# pointings_hadec_orig = GEOM.altaz2hadec(pointings_altaz_orig, latitude, units='degrees')
# pointings_radec_orig = NP.hstack(((lst-pointings_hadec_orig[:,0]).reshape(-1,1), pointings_hadec_orig[:,1].reshape(-1,1)))
# pointings_radec_orig[:,0] = pointings_radec_orig[:,0] % 360.0
pointings_dircos = GEOM.altaz2dircos(pointings_altaz, units='degrees')
pointings_hadec = GEOM.altaz2hadec(pointings_altaz,
latitude,
units='degrees')
pointings_radec = NP.hstack(((lst - pointings_hadec[:, 0]).reshape(-1, 1),
pointings_hadec[:, 1].reshape(-1, 1)))
pointings_radec[:, 0] = pointings_radec[:, 0] % 360.0
t_obs = NP.sum(t_snap)
elif pointing_info is not None:
pointing_init = NP.asarray(pointing_info[1:])
lst_init = pointing_info[0]
pointing_file = None
if t_snap is None:
raise NameError(
't_snap must be provided for an automated observing run')
if (n_snaps is None) and (t_obs is None):
raise NameError(
n_sky_sectors = 1
sky_sector = None # if None, use all sky sector. Accepted values are None, 0, 1, 2, or 3
if sky_sector is None:
sky_sector_str = '_all_sky_'
n_sky_sectors = 1
sky_sector = 0
else:
sky_sector_str = '_sky_sector_{0:0d}_'.format(sky_sector)
pointing_file = '/data3/t_nithyanandan/project_MWA/Aug23_obsinfo.txt'
pointing_info_from_file = NP.loadtxt(pointing_file, skiprows=2, comments='#', usecols=(1,2,3), delimiter=',')
obs_id = NP.loadtxt(pointing_file, skiprows=2, comments='#', usecols=(0,), delimiter=',', dtype=str)
lst = 15.0 * pointing_info_from_file[:,2]
pointings_altaz = OPS.reverse(pointing_info_from_file[:,:2].reshape(-1,2), axis=1)
pointings_dircos = GEOM.altaz2dircos(pointings_altaz, units='degrees')
pointings_hadec = GEOM.altaz2hadec(pointings_altaz, latitude, units='degrees')
max_abs_delay = 2.5 # in micro seconds
nside = 128
use_GSM = True
use_DSM = False
use_CSM = False
use_NVSS = False
use_SUMSS = False
use_MSS = False
use_GLEAM = False
use_PS = False
if use_GSM:
fg_str = 'asm'
def observe(
self, timestamp, Tsys, bandpass, pointing_center, skymodel, tobs, pb_min=0.1, fov_radius=None, lst=None
):
if bandpass.size != self.bp.shape[1]:
raise ValueError("bandpass length does not match.")
self.Tsys = self.Tsys + [Tsys]
self.vis_rms_freq = self.vis_rms_freq + [
2.0 * FCNST.k * Tsys / self.A_eff / self.eff_Q / NP.sqrt(2) / tobs / self.freq_resolution / CNST.Jy
]
self.tobs = self.tobs + [tobs]
self.lst = self.lst + [lst]
if self.timestamp == []:
self.bp = NP.asarray(bandpass).reshape(1, -1)
self.pointing_center = NP.asarray(pointing_center).reshape(1, -1)
else:
self.bp = NP.vstack((self.bp, NP.asarray(bandpass).reshape(1, -1)))
self.pointing_center = NP.vstack((self.pointing_center, NP.asarray(pointing_center).reshape(1, -1)))
pointing_lon = self.pointing_center[-1, 0]
pointing_lat = self.pointing_center[-1, 1]
if self.skycoords == "radec":
if self.pointing_coords == "hadec":
if lst is not None:
pointing_lon = lst - self.pointing_center[-1, 0]
pointing_lat = self.pointing_center[-1, 1]
else:
raise ValueError(
"LST must be provided. Sky coordinates are in RA-Dec format while pointing center is in HA-Dec format."
)
elif self.pointing_coords == "altaz":
pointing_lonlat = lst - GEOM.altaz2hadec(self.pointing_center[-1, :], self.latitude, units="degrees")
pointing_lon = pointing_lonlat[0]
pointing_lat = pointing_lonlat[1]
elif self.skycoords == "hadec":
if self.pointing_coords == "radec":
if lst is not None:
pointing_lon = lst - self.pointing_center[-1, 0]
pointing_lat = self.pointing_center[-1, 1]
else:
raise ValueError(
"LST must be provided. Sky coordinates are in RA-Dec format while pointing center is in HA-Dec format."
)
elif self.pointing_coords == "altaz":
pointing_lonlat = lst - GEOM.altaz2hadec(self.pointing_center[-1, :], self.latitude, units="degrees")
pointing_lon = pointing_lonlat[0]
pointing_lat = pointing_lonlat[1]
else:
if self.pointing_coords == "radec":
if lst is not None:
pointing_lonlat = GEOM.hadec2altaz(
NP.asarray([lst - self.pointing_center[-1, 0], self.pointing_center[-1, 1]]),
self.latitude,
units="degrees",
)
pointing_lon = pointing_lonlat[0]
pointing_lat = pointing_lonlat[1]
else:
raise ValueError(
"LST must be provided. Sky coordinates are in Alt-Az format while pointing center is in RA-Dec format."
)
elif self.pointing_coords == "hadec":
pointing_lonlat = GEOM.hadec2altaz(self.pointing_center, self.latitude, units="degrees")
pointing_lon = pointing_lonlat[0]
pointing_lat = pointing_lonlat[1]
pointing_phase = 0.0
baseline_in_local_frame = self.baseline
if self.baseline_coords == "equatorial":
baseline_in_local_frame = GEOM.xyz2enu(self.baseline, self.latitude, "degrees")
ptmp = self.pointing_center[-1, :] # Convert pointing center to Alt-Az coordinates
if self.pointing_coords == "hadec":
ptmp = GEOM.hadec2altaz(self.pointing_center[-1, :], self.latitude, units="degrees")
elif self.pointing_coords == "radec":
if lst is not None:
ptmp = GEOM.hadec2altaz(
NP.asarray([lst - self.pointing_center[-1, 0], self.pointing_center[-1, 1]]),
self.latitude,
units="degrees",
)
else:
raise ValueError(
"LST must be provided. Sky coordinates are in Alt-Az format while pointing center is in RA-Dec format."
)
ptmp = GEOM.altaz2dircos(ptmp, "degrees") # Convert pointing center to direction cosine coordinates
pointing_phase = (
2.0
* NP.pi
* NP.dot(baseline_in_local_frame.reshape(1, -1), ptmp.reshape(-1, 1))
* self.channels.reshape(1, -1)
/ FCNST.c
)
if fov_radius is None:
fov_radius = 90.0
# PDB.set_trace()
m1, m2, d12 = GEOM.spherematch(
pointing_lon,
pointing_lat,
skymodel.catalog.location[:, 0],
skymodel.catalog.location[:, 1],
fov_radius,
maxmatches=0,
)
# if fov_radius is not None:
# m1, m2, d12 = GEOM.spherematch(pointing_lon, pointing_lat, skymodel.catalog.location[:,0], skymodel.catalog.location[:,1], fov_radius, maxmatches=0)
# else:
# m1 = [0] * skymodel.catalog.location.shape[0]
# m2 = xrange(skymodel.catalog.location.shape[0])
# d12 = GEOM.sphdist(NP.empty(skymodel.catalog.shape[0]).fill(pointing_lon), NP.empty(skymodel.catalog.shape[0]).fill(pointing_lat), skymodel.catalog.location[:,0], skymodel.catalog.location[:,1])
if len(d12) != 0:
pb = NP.empty((len(d12), len(self.channels)))
fluxes = NP.empty((len(d12), len(self.channels)))
coords_str = self.skycoords
if self.skycoords == "radec":
coords_str = "altaz"
source_positions = GEOM.hadec2altaz(
NP.hstack(
(
NP.asarray(lst - skymodel.catalog.location[m2, 0]).reshape(-1, 1),
skymodel.catalog.location[m2, 1].reshape(-1, 1),
)
),
self.latitude,
"degrees",
)
for i in xrange(len(self.channels)):
# pb[:,i] = PB.primary_beam_generator(d12, self.channels[i]/1.0e9, 'degrees', self.telescope)
pb[:, i] = PB.primary_beam_generator(
source_positions, self.channels[i] / 1.0e9, "altaz", self.telescope
)
fluxes[:, i] = (
skymodel.catalog.flux_density[m2]
* (self.channels[i] / skymodel.catalog.frequency) ** skymodel.catalog.spectral_index[m2]
)
geometric_delays = DLY.geometric_delay(
baseline_in_local_frame,
source_positions,
altaz=(coords_str == "altaz"),
hadec=(coords_str == "hadec"),
latitude=self.latitude,
)
self.geometric_delays = self.geometric_delays + [geometric_delays.reshape(len(source_positions))]
phase_matrix = 2.0 * NP.pi * NP.repeat(
geometric_delays.reshape(-1, 1), len(self.channels), axis=1
) * NP.repeat(self.channels.reshape(1, -1), len(d12), axis=0) - NP.repeat(pointing_phase, len(d12), axis=0)
skyvis = NP.sum(
pb
* fluxes
* NP.repeat(NP.asarray(bandpass).reshape(1, -1), len(d12), axis=0)
* NP.exp(-1j * phase_matrix),
axis=0,
)
if fov_radius is not None:
self.obs_catalog_indices = self.obs_catalog_indices + [m2]
# self.obs_catalog = self.obs_catalog + [skymodel.catalog.subset(m2)]
else:
print "No sources found in the catalog within matching radius. Simply populating the observed visibilities with noise."
skyvis = NP.zeros((1, len(self.channels)))
if self.timestamp == []:
self.skyvis_freq = skyvis.reshape(1, -1)
self.vis_noise_freq = self.vis_rms_freq[-1] * (
NP.random.randn(len(self.channels)).reshape(1, -1)
+ 1j * NP.random.randn(len(self.channels)).reshape(1, -1)
)
self.vis_freq = self.skyvis_freq + self.vis_noise_freq
else:
self.skyvis_freq = NP.vstack((self.skyvis_freq, skyvis.reshape(1, -1)))
self.vis_noise_freq = NP.vstack(
(
self.vis_noise_freq,
self.vis_rms_freq[-1]
* (
NP.random.randn(len(self.channels)).reshape(1, -1)
+ 1j * NP.random.randn(len(self.channels)).reshape(1, -1)
),
)
)
self.vis_freq = NP.vstack(
(self.vis_freq, (self.skyvis_freq[-1, :] + self.vis_noise_freq[-1, :]).reshape(1, -1))
)
self.timestamp = self.timestamp + [timestamp]
