def RM(self, newtime, ra=None, dec=None):
"""
RM=i.RM(newtime, ra=None, dec=None))
compute Rotation Measure (rad/m**2)
along the zenith if ra is None
else along the specified direction
"""
TEC=self.__call__(newtime, ra=ra, dec=dec)
if TEC is None:
return None
Bx,By,Bz=self.getB(newtime)
if ra is None:
# the important B is the Bz
ZenPunc=0
AzPunc=0
else:
if not isinstance(ra,astropy.units.quantity.Quantity):
ra=angles.Angle(ra,unit=u.degree)
if not isinstance(dec,astropy.units.quantity.Quantity):
dec=angles.Angle(dec,unit=u.degree)
az,el=ephem_utils.radec2azel(ra.degree,dec.degree,newtime)
#logger.info('(RA,Dec)=(%.1f,%.1f) deg = (Az,El)=(%.1f,%.1f) deg' % (
# ra.degree,dec.degree,az,el))
az=angles.Angle(az,unit=u.degree)
el=angles.Angle(el,unit=u.degree)
za=angles.Angle(90,unit=u.degree)-el
dLat,dLong,AzPunc,ZenPunc=self.ionosphere_geometry(az,za)
# convert the components of B to the B along the LOS
# taken from ionFR.py
B=Bz*numpy.cos(ZenPunc) + numpy.sin(ZenPunc)*(By*numpy.sin(AzPunc)+Bx*numpy.cos(AzPunc))
# TEC is in 0.1 TECU
# B is in G
RM=RMconstant*B*TEC*1e15
return RM
def __call__(self, newtime, ra=None, dec=None):
"""
TEC=i(newtime, ra=None, dec=None)
returns the zenith TEC (if ra is None)
else the total TEC along the line-of-sight
in 0.1*TECU
"""
if ra is None:
return self.interpolate(newtime)
else:
if not isinstance(ra,astropy.units.quantity.Quantity):
ra=angles.Angle(ra,unit=u.degree)
if not isinstance(dec,astropy.units.quantity.Quantity):
dec=angles.Angle(dec,unit=u.degree)
az,el=ephem_utils.radec2azel(ra.degree,dec.degree,newtime)
#print '(RA,Dec)=(%.1f,%.1f) deg = (Az,El)=(%.1f,%.1f) deg' % (
# ra.degree,dec.degree,az,el)
az=angles.Angle(az,unit=u.degree)
el=angles.Angle(el,unit=u.degree)
za=angles.Angle(90,unit=u.degree)-el
dLat,dLong,AzPunc,ZenPunc=self.ionosphere_geometry(az,za)
#print dLat.to(u.degree),dLong.to(u.degree),AzPunc.to(u.degree),ZenPunc.to(u.degree)
# return the full line of sight TEC, converting from vertical
return self.interpolate(newtime, dlong=dLong,
dlat=dLat)/numpy.cos(ZenPunc).value
self.calibration = self._Schedule_Metadata.calibration
self.calibrators = self._Schedule_Metadata.calibrators
except (psycopg2.InternalError, psycopg2.ProgrammingError), e:
logger.warning('Database error=%s' % (e.pgerror))
db.rollback()
mwa = ephem_utils.Obs[ephem_utils.obscode['MWA']]
if (self._RFstream.ra is not None):
logger.info('Found (RA,Dec) in RFstream (%.5f,%.5f)\n' %
(self._RFstream.ra, self._RFstream.dec))
self.RA = self._RFstream.ra
self.Dec = self._RFstream.dec
mwatime = ephem_utils.MWATime(gpstime=self.observation_number)
self.azimuth, self.elevation = ephem_utils.radec2azel(
self.RA, self.Dec, self.observation_number)
self.HA = ephem_utils.HA(self.LST, self.RA, self.Dec,
self.epoch) / 15.0
elif (self._RFstream.azimuth is not None):
logger.info('Found (Az,El) in RFstream (%.5f,%.5f)\n' %
(self._RFstream.azimuth, self._RFstream.elevation))
self.azimuth = self._RFstream.azimuth
self.elevation = self._RFstream.elevation
self.RA, self.Dec = ephem_utils.azel2radec(
self.azimuth, self.elevation, self.observation_number)
self.HA = ephem_utils.HA(self.LST, self.RA, self.Dec,
self.epoch) / 15.0
elif (self._RFstream.hex is not None
and len(self._RFstream.hex) > 0):
except:
logger.error("Unable to find coordinates for '%s'" % options.source)
sys.exit(1)
if coord is None:
logger.error('Must supply one of (RA,Dec), (l,b), source')
sys.exit(1)
observation_num = get_observation_info.find_closest_observation(observationid,
maxdiff=0,
db=db)
if observation_num is None:
logger.error('Observation not found for gpstime=%d' % observationid)
sys.exit(1)
obs = get_observation_info.MWA_Observation(observationid, db=db)
Az, El = ephem_utils.radec2azel(coord.ra.degree, coord.dec.degree,
obs.observation_number)
# first go from altitude to zenith angle
theta = numpy.radians((90 - El))
phi = numpy.radians(Az)
# this is the response for XX and YY
try:
respX, respY = primary_beam.MWA_Tile_analytic(theta,
phi,
freq=obs.center_channel *
1.28e6,
delays=obs.delays)
except:
logger.error('Error creating primary beams\n')
sys.exit(1)
rX = numpy.real(numpy.conj(respX) * respX)