def main(args):
# Validate
if args.pol not in ('EW', 'NS'):
raise ValueError("Invalid polarization: %s" % args.pol)
# Get the site information
if args.lwasv:
nam = 'lwasv'
sta = stations.lwasv
elif args.ovrolwa:
nam = 'ovro'
sta = stations.lwa1
sta.lat, sta.lon, sta.elev = ('37.23977727', '-118.2816667', 1182.89)
else:
nam = 'lwa1'
sta = stations.lwa1
# Read in the skymap (GSM or LF map @ 74 MHz)
if not args.lfsm:
smap = skymap.SkyMapGSM(freq_MHz=args.frequency/1e6)
if args.verbose:
print("Read in GSM map at %.2f MHz of %s pixels; min=%f, max=%f" % (args.frequency/1e6, len(smap.ra), smap._power.min(), smap._power.max()))
else:
smap = skymap.SkyMapLFSM(freq_MHz=args.frequency/1e6)
if args.verbose:
print("Read in LFSM map at %.2f MHz of %s pixels; min=%f, max=%f" % (args.frequency/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 args.pol == 'EW':
beamCoeff = beamDict['fitX']
else:
beamCoeff = beamDict['fitY']
try:
beamDict.close()
except AttributeError:
pass
alphaE = numpy.polyval(beamCoeff[0,0,:], args.frequency)
betaE = numpy.polyval(beamCoeff[0,1,:], args.frequency)
gammaE = numpy.polyval(beamCoeff[0,2,:], args.frequency)
deltaE = numpy.polyval(beamCoeff[0,3,:], args.frequency)
alphaH = numpy.polyval(beamCoeff[1,0,:], args.frequency)
betaH = numpy.polyval(beamCoeff[1,1,:], args.frequency)
gammaH = numpy.polyval(beamCoeff[1,2,:], args.frequency)
deltaH = numpy.polyval(beamCoeff[1,3,:], args.frequency)
if args.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 args.empirical:
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 args.frequency/1e6 < cFreqs.min() or args.frequency/1e6 > cFreqs.max():
print("WARNING: Input frequency of %.3f MHz is out of range, skipping correction" % (args.frequency/1e6,))
corrFnc = None
else:
fCors = cAlts*0.0
for i in range(fCors.size):
ffnc = interp1d(cFreqs, cCorrs[:,i], bounds_error=False)
fCors[i] = ffnc(args.frequency/1e6)
corrFnc = interp1d(cAlts, fCors, bounds_error=False)
else:
corrFnc = None
def compute_beam_pattern(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 args.do_plot:
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" % (args.pol, args.frequency/1e6))
pylab.imshow(compute_beam_pattern(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, 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 = compute_beam_pattern(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" % \
(args.pol, args.frequency/1e6, nam.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" % (nam, args.pol, args.frequency/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()
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 test_ProjectedSkyMap_get_direction_cosines_LFSM(self):
"""Test skymap.ProjectedSkyMap.get_direction_cosines() method using SkyMapLFSM."""
s = skymap.SkyMapLFSM()
p = skymap.ProjectedSkyMap(s, 20, 30, astro.get_julian_from_sys())
p.get_direction_cosines()
def test_ProjectedSkyMap_compute_visible_power_LFSM(self):
"""Test skymap.ProjectedSkyMap.compute_visible_power() method using SkyMapLFSM."""
s = skymap.SkyMapLFSM()
p = skymap.ProjectedSkyMap(s, 20, 30, astro.get_julian_from_sys())
p.compute_visible_power()
def test_ProjectedSkyMap_init_LFSM(self):
"""Test skymap.ProjectedSkyMap constructor method using SkyMapLFSM."""
s = skymap.SkyMapLFSM()
skymap.ProjectedSkyMap(s, 20, 30, astro.get_julian_from_sys())
def test_SkyMapLFSM_compute_total_power(self):
"""Test skymap.SkyMapLFSM.compute_total_power() method."""
s = skymap.SkyMapLFSM()
s.compute_total_power()
def test_SkyMapLFSM_init(self):
"""Test skymap.SkyMapLFSM class constructor method."""
skymap.SkyMapLFSM()