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]
roi_sector_altaz = NP.asarray(NP.where(NP.logical_or(NP.logical_and(az[roi_altaz] >= -0.5*180.0/n_sky_sectors + sky_sector*180.0/n_sky_sectors, az[roi_altaz] < -0.5*180.0/n_sky_sectors + (sky_sector+1)*180.0/n_sky_sectors), NP.logical_and(az[roi_altaz] >= 180.0 - 0.5*180.0/n_sky_sectors + sky_sector*180.0/n_sky_sectors, az[roi_altaz] < 180.0 - 0.5*180.0/n_sky_sectors + (sky_sector+1)*180.0/n_sky_sectors)))).ravel()
pb = NP.empty(xvect.size)
pb.fill(NP.nan)
bd = NP.empty(xvect.size)
bd.fill(NP.nan)
pb[roi_altaz] = PB.primary_beam_generator(altaz[roi_altaz,:], freq, telescope=telescope, skyunits='altaz', freq_scale='Hz', pointing_center=fhd_obsid_pointing_altaz)
# bd[roi_altaz] = backdrop.ravel()[roi_altaz]
# pb[roi_altaz[roi_sector_altaz]] = PB.primary_beam_generator(altaz[roi_altaz[roi_sector_altaz],:], freq, telescope=telescope, skyunits='altaz', freq_scale='Hz', phase_center=fhd_obsid_pointing_altaz)
bd[roi_altaz[roi_sector_altaz]] = backdrop.ravel()[roi_altaz[roi_sector_altaz]]
overlay['pbeam'] = pb
overlay['backdrop'] = bd
overlay['roi_obj_inds'] = roi_altaz
overlay['roi_sector_inds'] = roi_altaz[roi_sector_altaz]
overlay['delay_map'] = NP.empty((n_bins_baseline_orientation, xvect.size))
overlay['delay_map'].fill(NP.nan)
overlay['delay_map'][:,roi_altaz] = (DLY.geometric_delay(cardinal_bl, altaz[roi_altaz,:], altaz=True, dircos=False, hadec=False, latitude=latitude)-DLY.geometric_delay(cardinal_bl, pc, altaz=False, dircos=True, hadec=False, latitude=latitude)).T
if use_CSM or use_SUMSS or use_NVSS or use_PS:
src_hadec = NP.hstack(((fhd_lst-ctlgobj.location[:,0]).reshape(-1,1), ctlgobj.location[:,1].reshape(-1,1)))
src_altaz = GEOM.hadec2altaz(src_hadec, latitude, units='degrees')
roi_src_altaz = NP.asarray(NP.where(src_altaz[:,0] >= 0.0)).ravel()
roi_pbeam = PB.primary_beam_generator(src_altaz[roi_src_altaz,:], freq, telescope=telescope, skyunits='altaz', freq_scale='Hz', pointing_center=fhd_obsid_pointing_altaz)
overlay['src_ind'] = roi_src_altaz
overlay['pbeam_on_src'] = roi_pbeam.ravel()
# delay_envelope = DLY.delay_envelope(cardinal_bl, dircos[roi_altaz,:])
# overlay['delay_map'][:,roi_altaz] = (DLY.geometric_delay(cardinal_bl, altaz[roi_altaz,:], altaz=True, dircos=False, hadec=False, latitude=latitude)-DLY.geometric_delay(cardinal_bl, fhd_obsid_pointing_altaz, altaz=True, dircos=False, hadec=False, latitude=latitude)).T
# roi_obj_inds += [roi_altaz]
elif backdrop_coords == 'dircos':
havect = fhd_lst - ra_deg
fg_altaz = GEOM.hadec2altaz(NP.hstack((havect.reshape(-1,1),dec_deg.reshape(-1,1))), latitude, units='degrees')
fg_dircos = GEOM.altaz2dircos(fg_altaz, units='degrees')
pointing_center=fhd_obsid_pointing_altaz)
# bd[roi_altaz] = backdrop.ravel()[roi_altaz]
# pb[roi_altaz[roi_sector_altaz]] = PB.primary_beam_generator(altaz[roi_altaz[roi_sector_altaz],:], freq, telescope=telescope, skyunits='altaz', freq_scale='Hz', phase_center=fhd_obsid_pointing_altaz)
bd[roi_altaz[roi_sector_altaz]] = backdrop.ravel()[
roi_altaz[roi_sector_altaz]]
overlay['pbeam'] = pb
overlay['backdrop'] = bd
overlay['roi_obj_inds'] = roi_altaz
overlay['roi_sector_inds'] = roi_altaz[roi_sector_altaz]
overlay['delay_map'] = NP.empty(
(n_bins_baseline_orientation, xvect.size))
overlay['delay_map'].fill(NP.nan)
overlay['delay_map'][:, roi_altaz] = (
DLY.geometric_delay(cardinal_bl,
altaz[roi_altaz, :],
altaz=True,
dircos=False,
hadec=False,
latitude=latitude) -
DLY.geometric_delay(cardinal_bl,
pc,
altaz=False,
dircos=True,
hadec=False,
latitude=latitude)).T
if use_CSM or use_SUMSS or use_NVSS or use_PS:
src_hadec = NP.hstack(
((fhd_lst - ctlgobj.location[:, 0]).reshape(-1, 1),
ctlgobj.location[:, 1].reshape(-1, 1)))
src_altaz = GEOM.hadec2altaz(src_hadec, latitude, units='degrees')
roi_src_altaz = NP.asarray(
NP.where(src_altaz[:, 0] >= 0.0)).ravel()