def __init__(self, skymap_object, lat, lon, utc_jd):
"""
Initialize the skymap at input lat,lon (decimal degrees) and time (in
UTC julian day).
"""
self.skymap_object = skymap_object
assert -90 <= lat <= 90, ValueError('lat = %g not in [-90,90]' % lat)
assert -360 <= lon <= 360, ValueError('lon = %g not in [-360,360]' % lon)
self.lat = lat
self.lon = lon
self.time = utc_jd
# Compute the ra and dec locations to a altitude and azimuth. This requires a lat/lon and a time (UTC).
# Alt and Az are compressed to show only the visible source.
## Extract the RA/dec values
ra = self.skymap_object.ra
dec = self.skymap_object.dec
## Compute the LST at the lat/lon (hours)
lst = astro.get_local_sidereal_time(self.lon, self.time)
## RA -> HA (deg)
ha = lst*15.0 - ra
## HA, dec, and lat in degrees to alt and az in radians
sinAlt = sin(dec*pi/180)*sin(self.lat*pi/180) + cos(dec*pi/180)*cos(lat*pi/180)*cos(ha*pi/180)
sinAlt = clip(sinAlt, -1.0, 1.0)
alt = arcsin(sinAlt)
cosAz = (sin(dec*pi/180)-sinAlt*sin(self.lat*pi/180))/(cos(alt)*cos(lat*pi/180))
cosAz = clip(cosAz, -1.0, 1.0)
az = arccos(cosAz)
swap = where(sin(ha*pi/180) > 0)
az[swap] = 2*pi-az[swap]
## Convert to alt and az to degrees
self.alt = alt*180/pi
self.az = az*180/pi
# Compress the az/alt so that only the visible sources are available. "
visibleMask = self.alt > 0.0
#Compress arrays to hide non-visible sources
self.visibleAlt = compress(visibleMask, self.alt)
self.visibleAz = compress(visibleMask, self.az)
self.visiblePower = compress(visibleMask, self.skymap_object._power)
try:
pixelSolidAngle = (2.0 * pi)**2/(self.skymap_object.numPixelsX*self.skymap_object.numPixelsY)
except AttributeError:
pixelSolidAngle = 2.5566346e-4
fractionSolidAngle = (1.0/4.0*pi) * pixelSolidAngle
# The cosine term is the projection of the receiving area onto the direction
# of the source
normalizedPower = self.skymap_object.normalize_power() * fractionSolidAngle
self.visibleNormalizedPower = compress(visibleMask, normalizedPower)
#self.visibleNormalizedPower = self.visiblePower*cos(self.visibleAlt * self.skymap_object.degToRad)
self.visibleRa = compress(visibleMask, self.skymap_object.ra)
self.visibleDec = compress(visibleMask, self.skymap_object.dec)
def sidereal(self, time_):
"""
Return the apparent sidereal time for this location.
The 'time_' parameter should be set to a Time instance providing
the time of interest.
Returns sidereal time as a float in range [0.0, 24.0).
"""
if not isinstance(time_, Time):
raise TypeError("time_ must be type transform.Time")
return astro.get_local_sidereal_time(self._posn.lng, time_.utc_jd)
def main(args):
# Beam
beamFilename = args.filename
beamDict = numpy.load(beamFilename)
beam = beamDict['beam']
beam /= beam.max()
# Station, polarization, frequency, and beam simulation resolution
name = beamDict['station'].item()
pol = beamDict['pol'].item()
freq = beamDict['freq'].item()
try:
res = beamDict['res'].item()
except KeyError:
res = 1.0
ires = 1.0 / (min([1.0, res]))
# Get the site information
if name == 'lwa1':
sta = stations.lwa1
elif name == 'lwasv':
sta = stations.lwasv
else:
raise RuntimeError("Unknown site: %s" % name)
# Read in the skymap (GSM or LF map @ 74 MHz)
if not args.lfsm:
smap = skymap.SkyMapGSM(freq_MHz=freq/1e6)
if args.verbose:
print("Read in GSM map at %.2f MHz of %s pixels; min=%f, max=%f" % (freq/1e6, len(smap.ra), smap._power.min(), smap._power.max()))
else:
smap = skymap.SkyMapLFSM(freq_MHz=freq/1e6)
if args.verbose:
print("Read in LFSM map at %.2f MHz of %s pixels; min=%f, max=%f" % (freq/1e6, len(smap.ra), smap._power.min(), smap._power.max()))
def BeamPattern(az, alt, beam=beam, ires=ires):
iAz = (numpy.round(az*ires)).astype(numpy.int32)
iAlt = (numpy.round(alt*ires)).astype(numpy.int32)
return beam[iAz,iAlt]
if args.do_plot:
az = numpy.arange(0,360*ires+1,1) / float(ires)
alt = numpy.arange(0,90*ires+1,1) / float(ires)
alt, az = numpy.meshgrid(alt, az)
pylab.figure(1)
pylab.title("Beam Response: %s pol. @ %0.2f MHz" % (pol, freq/1e6))
pylab.imshow(BeamPattern(az, alt), interpolation='nearest', extent=(0,359, 0,89), origin='lower')
pylab.xlabel("Azimuth [deg]")
pylab.ylabel("Altitude [deg]")
pylab.grid(1)
pylab.draw()
# Calculate times in both site LST and UTC
t0 = astro.get_julian_from_sys()
lst = astro.get_local_sidereal_time(sta.long*180.0/math.pi, t0) / 24.0
t0 -= lst*(23.933/24.0) # Compensate for shorter sidereal days
times = numpy.arange(0.0, 1.0, args.time_step/1440.0) + t0
lstList = []
powListAnt = []
for t in times:
# Project skymap to site location and observation time
pmap = skymap.ProjectedSkyMap(smap, sta.lat*180.0/math.pi, sta.long*180.0/math.pi, t)
lst = astro.get_local_sidereal_time(sta.long*180.0/math.pi, t)
lstList.append(lst)
# Convolution of user antenna pattern with visible skymap
gain = BeamPattern(pmap.visibleAz, pmap.visibleAlt)
powerAnt = (pmap.visiblePower * gain).sum() / gain.sum()
powListAnt.append(powerAnt)
if args.verbose:
lstH = int(lst)
lstM = int((lst - lstH)*60.0)
lstS = ((lst - lstH)*60.0 - lstM)*60.0
sys.stdout.write("LST: %02i:%02i:%04.1f, Power_ant: %.1f K \r" % (lstH, lstM, lstS, powerAnt))
sys.stdout.flush()
sys.stdout.write("\n")
# Plot results
if args.do_plot:
pylab.figure(2)
pylab.title("Driftcurve: %s pol. @ %0.2f MHz - %s" % \
(pol, freq/1e6, name.upper()))
pylab.plot(lstList, powListAnt, "ro",label="Antenna Pattern")
pylab.xlabel("LST [hours]")
pylab.ylabel("Temp. [K]")
pylab.grid(2)
pylab.draw()
pylab.show()
outputFile = "driftcurve_%s_%s_%.2f.txt" % (name, pol, freq/1e6)
print("Writing driftcurve to file '%s'" % outputFile)
mf = open(outputFile, "w")
for lst,pow in zip(lstList, powListAnt):
mf.write("%f %f\n" % (lst,pow))
mf.close()
def main(args):
# Parse command line
config = parseOptions(args)
# Get the site information
if config['site'] == 'lwa1':
sta = stations.lwa1
elif config['site'] == 'lwasv':
sta = stations.lwasv
elif config['site'] == 'ovro':
sta = stations.lwa1
sta.lat, sta.lon, sta.elev = ('37.2397808', '-118.2816819', 1183.4839)
else:
raise RuntimeError("Unknown site: %s" % config['site'])
# Read in the skymap (GSM or LF map @ 74 MHz)
if config['GSM']:
smap = skymap.SkyMapGSM(freqMHz=config['freq']/1e6)
if config['verbose']:
print "Read in GSM map at %.2f MHz of %s pixels; min=%f, max=%f" % (config['freq']/1e6, len(smap.ra), smap._power.min(), smap._power.max())
else:
smap = skymap.SkyMapLFSM(freqMHz=config['freq']/1e6)
if config['verbose']:
print "Read in LFSM map at %.2f MHz of %s pixels; min=%f, max=%f" % (config['freq']/1e6, len(smap.ra), smap._power.min(), smap._power.max())
# Get the emperical model of the beam and compute it for the correct frequencies
beamDict = numpy.load(os.path.join(dataPath, 'lwa1-dipole-emp.npz'))
if config['pol'] == 'EW':
beamCoeff = beamDict['fitX']
else:
beamCoeff = beamDict['fitY']
try:
beamDict.close()
except AttributeError:
pass
alphaE = numpy.polyval(beamCoeff[0,0,:], config['freq'])
betaE = numpy.polyval(beamCoeff[0,1,:], config['freq'])
gammaE = numpy.polyval(beamCoeff[0,2,:], config['freq'])
deltaE = numpy.polyval(beamCoeff[0,3,:], config['freq'])
alphaH = numpy.polyval(beamCoeff[1,0,:], config['freq'])
betaH = numpy.polyval(beamCoeff[1,1,:], config['freq'])
gammaH = numpy.polyval(beamCoeff[1,2,:], config['freq'])
deltaH = numpy.polyval(beamCoeff[1,3,:], config['freq'])
if config['verbose']:
print "Beam Coeffs. X: a=%.2f, b=%.2f, g=%.2f, d=%.2f" % (alphaH, betaH, gammaH, deltaH)
print "Beam Coeffs. Y: a=%.2f, b=%.2f, g=%.2f, d=%.2f" % (alphaE, betaE, gammaE, deltaE)
if config['corr']:
corrDict = numpy.load(os.path.join(dataPath, 'lwa1-dipole-cor.npz'))
cFreqs = corrDict['freqs']
cAlts = corrDict['alts']
if corrDict['degrees'].item():
cAlts *= numpy.pi / 180.0
cCorrs = corrDict['corrs']
corrDict.close()
if config['freq']/1e6 < cFreqs.min()-11 or config['freq']/1e6 > cFreqs.max()+11:
print "WARNING: Input frequency of %.3f MHz is out of range, skipping correction"
corrFnc = None
else:
fCors = cAlts*0.0
for i in xrange(fCors.size):
ffnc = interpextrap1d(cFreqs, cCorrs[:,i])
fCors[i] = ffnc(config['freq']/1e6)
corrFnc = interp1d(cAlts, fCors, bounds_error=False)
else:
corrFnc = None
def BeamPattern(az, alt, corr=corrFnc):
zaR = numpy.pi/2 - alt*numpy.pi / 180.0
azR = az*numpy.pi / 180.0
c = 1.0
if corrFnc is not None:
c = corrFnc(alt*numpy.pi / 180.0)
c = numpy.where(numpy.isfinite(c), c, 1.0)
pE = (1-(2*zaR/numpy.pi)**alphaE)*numpy.cos(zaR)**betaE + gammaE*(2*zaR/numpy.pi)*numpy.cos(zaR)**deltaE
pH = (1-(2*zaR/numpy.pi)**alphaH)*numpy.cos(zaR)**betaH + gammaH*(2*zaR/numpy.pi)*numpy.cos(zaR)**deltaH
return c*numpy.sqrt((pE*numpy.cos(azR))**2 + (pH*numpy.sin(azR))**2)
if config['enableDisplay']:
az = numpy.zeros((90,360))
alt = numpy.zeros((90,360))
for i in range(360):
az[:,i] = i
for i in range(90):
alt[i,:] = i
pylab.figure(1)
pylab.title("Beam Response: %s pol. @ %0.2f MHz" % (config['pol'], config['freq']/1e6))
pylab.imshow(BeamPattern(az, alt), extent=(0,359, 0,89), origin='lower')
pylab.xlabel("Azimuth [deg]")
pylab.ylabel("Altitude [deg]")
pylab.grid(1)
pylab.draw()
# Calculate times in both site LST and UTC
t0 = astro.get_julian_from_sys()
lst = astro.get_local_sidereal_time(sta.long*180.0/math.pi, t0) / 24.0
t0 -= lst*(23.933/24.0) # Compensate for shorter sidereal days
times = numpy.arange(0.0, 1.0, config['tStep']/1440.0) + t0
lstList = []
powListAnt = []
for t in times:
# Project skymap to site location and observation time
pmap = skymap.ProjectedSkyMap(smap, sta.lat*180.0/math.pi, sta.long*180.0/math.pi, t)
lst = astro.get_local_sidereal_time(sta.long*180.0/math.pi, t)
lstList.append(lst)
# Convolution of user antenna pattern with visible skymap
gain = BeamPattern(pmap.visibleAz, pmap.visibleAlt)
powerAnt = (pmap.visiblePower * gain).sum() / gain.sum()
powListAnt.append(powerAnt)
if config['verbose']:
lstH = int(lst)
lstM = int((lst - lstH)*60.0)
lstS = ((lst - lstH)*60.0 - lstM)*60.0
sys.stdout.write("LST: %02i:%02i:%04.1f, Power_ant: %.1f K\r" % (lstH, lstM, lstS, powerAnt))
sys.stdout.flush()
sys.stdout.write("\n")
# plot results
if config['enableDisplay']:
pylab.figure(2)
pylab.title("Driftcurve: %s pol. @ %0.2f MHz - %s" % \
(config['pol'], config['freq']/1e6, config['site'].upper()))
pylab.plot(lstList, powListAnt, "ro", label="Antenna Pattern")
pylab.xlabel("LST [hours]")
pylab.ylabel("Temp. [K]")
pylab.grid(2)
pylab.draw()
pylab.show()
outputFile = "driftcurve_%s_%s_%.2f.txt" % (config['site'], config['pol'], config['freq']/1e6)
if config['tag'] is not None:
base, ext = os.path.splitext(outputFile)
outputFile = "%s_%s%s" % (base, config['tag'], ext)
print "Writing driftcurve to file '%s'" % outputFile
mf = file(outputFile, "w")
for lst,pow in zip(lstList, powListAnt):
mf.write("%f %f\n" % (lst, pow))
mf.close()
def main(args):
# Parse command line
config = parseOptions(args)
# Get the site information for LWA-1
sta = stations.lwa1
# Read in the skymap (GSM or LF map @ 74 MHz)
if config['GSM']:
smap = skymap.SkyMapGSM(freqMHz=config['freq'] / 1e6)
if config['verbose']:
print "Read in GSM map at %.2f MHz of %s pixels; min=%f, max=%f" % (
config['freq'] / 1e6, len(
smap.ra), smap._power.min(), smap._power.max())
else:
smap = skymap.SkyMap(freqMHz=config['freq'] / 1e6)
if config['verbose']:
print "Read in LF map at %.2f MHz of %d x %d pixels; min=%f, max=%f" % (
config['freq'] / 1e6, smap.numPixelsX, smap.numPixelsY,
smap._power.min(), smap._power.max())
# Get the emperical model of the beam and compute it for the correct frequencies
beamDict = numpy.load(os.path.join(dataPath, 'lwa1-dipole-emp.npz'))
if config['pol'] == 'EW':
beamCoeff = beamDict['fitX']
else:
beamCoeff = beamDict['fitY']
try:
beamDict.close()
except AttributeError:
pass
alphaE = numpy.polyval(beamCoeff[0, 0, :], config['freq'])
betaE = numpy.polyval(beamCoeff[0, 1, :], config['freq'])
gammaE = numpy.polyval(beamCoeff[0, 2, :], config['freq'])
deltaE = numpy.polyval(beamCoeff[0, 3, :], config['freq'])
alphaH = numpy.polyval(beamCoeff[1, 0, :], config['freq'])
betaH = numpy.polyval(beamCoeff[1, 1, :], config['freq'])
gammaH = numpy.polyval(beamCoeff[1, 2, :], config['freq'])
deltaH = numpy.polyval(beamCoeff[1, 3, :], config['freq'])
if config['verbose']:
print "Beam Coeffs. X: a=%.2f, b=%.2f, g=%.2f, d=%.2f" % (
alphaH, betaH, gammaH, deltaH)
print "Beam Coeffs. Y: a=%.2f, b=%.2f, g=%.2f, d=%.2f" % (
alphaE, betaE, gammaE, deltaE)
def BeamPattern(az, alt):
zaR = numpy.pi / 2 - alt * numpy.pi / 180.0
azR = az * numpy.pi / 180.0
pE = (
1 -
(2 * zaR / numpy.pi)**alphaE) * numpy.cos(zaR)**betaE + gammaE * (
2 * zaR / numpy.pi) * numpy.cos(zaR)**deltaE
pH = (
1 -
(2 * zaR / numpy.pi)**alphaH) * numpy.cos(zaR)**betaH + gammaH * (
2 * zaR / numpy.pi) * numpy.cos(zaR)**deltaH
return numpy.sqrt((pE * numpy.cos(azR))**2 + (pH * numpy.sin(azR))**2)
if config['enableDisplay']:
az = numpy.zeros((90, 360))
alt = numpy.zeros((90, 360))
for i in range(360):
az[:, i] = i
for i in range(90):
alt[i, :] = i
pylab.figure(1)
pylab.title("Beam Response: %s pol. @ %0.2f MHz" %
(config['pol'], config['freq'] / 1e6))
pylab.imshow(BeamPattern(az, alt),
extent=(0, 359, 0, 89),
origin='lower')
pylab.xlabel("Azimuth [deg]")
pylab.ylabel("Altitude [deg]")
pylab.grid(1)
pylab.draw()
# Calculate times in both site LST and UTC
t0 = astro.get_julian_from_sys()
lst = astro.get_local_sidereal_time(sta.long * 180.0 / math.pi, t0) / 24.0
t0 -= lst * (23.933 / 24.0) # Compensate for shorter sidereal days
times = numpy.arange(0.0, 1.0, config['tStep'] / 1440.0) + t0
lstList = []
powListAnt = []
for t in times:
# Project skymap to site location and observation time
pmap = skymap.ProjectedSkyMap(smap, sta.lat * 180.0 / math.pi,
sta.long * 180.0 / math.pi, t)
lst = astro.get_local_sidereal_time(sta.long * 180.0 / math.pi, t)
lstList.append(lst)
if config['GSM']:
cdec = numpy.ones_like(pmap.visibleDec)
else:
cdec = numpy.cos(pmap.visibleDec * smap.degToRad)
# Convolution of user antenna pattern with visible skymap
gain = BeamPattern(pmap.visibleAz, pmap.visibleAlt)
powerAnt = (pmap.visiblePower * gain * cdec).sum() / (gain *
cdec).sum()
powListAnt.append(powerAnt)
if config['verbose']:
lstH = int(lst)
lstM = int((lst - lstH) * 60.0)
lstS = ((lst - lstH) * 60.0 - lstM) * 60.0
sys.stdout.write("LST: %02i:%02i:%04.1f, Power_ant: %.1f K\r" %
(lstH, lstM, lstS, powerAnt))
sys.stdout.flush()
sys.stdout.write("\n")
# plot results
if config['enableDisplay']:
pylab.figure(2)
pylab.title("Driftcurve: %s pol. @ %0.2f MHz - LWA-1" % \
(config['pol'], config['freq']/1e6))
pylab.plot(lstList, powListAnt, "ro", label="Antenna Pattern")
pylab.xlabel("LST [hours]")
pylab.ylabel("Temp. [K]")
pylab.grid(2)
pylab.draw()
pylab.show()
outputFile = "driftcurve_%s_%s_%.2f.txt" % ('lwa1', config['pol'],
config['freq'] / 1e6)
print "Writing driftcurve to file '%s'" % outputFile
mf = file(outputFile, "w")
for lst, pow in zip(lstList, powListAnt):
mf.write("%f %f\n" % (lst, pow))
mf.close()
lwa_gm_hms = astro.deg_to_hms(-lwa_lnlat.lng)
lwa_gm_off = lwa_gm_hms.to_sec()
print('GM Offset: %s (%0.3f)' % (lwa_gm_hms, lwa_gm_off))
# get current UTC time from system clock
utc = astro.get_julian_from_sys()
utcd = astro.get_date(utc)
lcld = utcd.to_zone()
unixt = astro.get_timet_from_julian(utc)
# caculate sidereal times
gm_sid = astro.get_apparent_sidereal_time(utc)
lwa_sid = astro.get_local_sidereal_time(lwa_lnlat.lng, utc)
print('---------------------------------------------------------------')
print('Current time')
print('---------------------------------------------------------------')
print('UTC time: %s (%0.3f)' % (utcd, utc))
print('%s local time: %s' % (nam, str(lcld)))
print('GM sidereal time: %0.3f' % gm_sid)
print('%s sidereal time: %0.3f' % (nam, lwa_sid))
print('UNIX time: %d' % unixt)
# calculate nutation
nut = astro.get_nutation(utc)
(nut_lng, nut_obl, nut_ecl) = nut.format()