def VisibilitySimulator(s, PBs, ps, times, coords):
print "Now simulating visibilities (assuming XX beams only)..."
if s.GSMNSIDE < s.mapNSIDE:
s.GSMNSIDE = s.mapNSIDE
coordsGSM = Geometry.Coordinates(s, useAnotherResolution=s.GSMNSIDE)
visibilities = np.zeros([len(times.LSTs), len(s.baselines)], dtype=complex)
#TODO: this ignores polarization and differing primary beams
if s.simulateVisibilitiesWithGSM:
GSM = GlobalSkyModel(s.freq, s.GSMlocation, s.GSMNSIDE)
interpoltedGSMRotated = hp.get_interp_val(
GSM.hpMap, -coordsGSM.galCoords.b.radian + np.pi / 2,
np.asarray(coordsGSM.galCoords.l.radian))
#loop over times and baselines to calculate visibilities
for t in range(len(times.LSTs)):
pixelAlts, pixelAzs = Geometry.convertEquatorialToHorizontal(
s, coordsGSM.pixelRAs, coordsGSM.pixelDecs, times.LSTs[t])
rHatVectors = Geometry.convertAltAzToCartesian(pixelAlts, pixelAzs)
primaryBeam = hp.get_interp_val(
PBs.beamSquared("X", "x", s.pointings[t]),
np.pi / 2 - pixelAlts, pixelAzs)
for b in range(len(s.baselines)):
exponent = np.exp(-1j * s.k *
np.dot(rHatVectors, s.baselines[b]))
visibilities[t,
b] += np.sum(interpoltedGSMRotated * primaryBeam *
exponent) * 4 * np.pi / len(
GSM.hpMap) / s.convertJyToKFactor
if s.simulateVisibilitiesWithPointSources and ps.nSources > 0:
for t in range(len(times.LSTs)):
psAlts, psAzs = Geometry.convertEquatorialToHorizontal(
s, ps.RAs, ps.decs, times.LSTs[t])
rHatVectors = Geometry.convertAltAzToCartesian(psAlts, psAzs)
primaryBeam = hp.get_interp_val(
PBs.beamSquared("X", "x", s.pointings[t]), np.pi / 2 - psAlts,
psAzs)
for b in range(len(s.baselines)):
exponent = np.exp(-1j * s.k *
np.dot(rHatVectors, s.baselines[b]))
visibilities[t, b] += np.sum(ps.scaledFluxes * primaryBeam *
exponent)
return visibilities
def Mapmaker(mainDirectory,
freq=150,
useLogFile=False,
configFile="configuration.txt",
**kwargs):
"""This function makes maps from visibilities and also calculates the associated map statistics.
Saves the results to binary (as pickles or numpy arryas) and returns the folder where they are located"""
#Load in everything we need, figure out which LSTs to work with
print "Now working on mapmaking at " + str(freq) + " MHz..."
s = Specifications(mainDirectory, configFile, freq)
s.OverrideSpecifications(kwargs)
os.system("rm -rf " + s.resultsFolder)
os.system("mkdir " + s.resultsFolder)
if useLogFile: sys.stdout = open(s.resultsFolder + 'log.txt', 'w')
#Info related to time, geometry, primary beams, and point sources
times = Geometry.Times(s)
times.CutOutUnusedLSTsAndGroupIntoSnapshots(s)
coords = Geometry.Coordinates(s)
PBs = PrimaryBeams(s)
ps = PointSourceCatalog(s, times)
if s.useAdaptiveHEALPixForPSF: coords.convertToAdaptiveHEALPix(s, times)
#Simulate or load visibilities
if s.simulateVisibilitiesWithGSM or s.simulateVisibilitiesWithPointSources:
visibilities = VisibilitySimulator(s, PBs, ps, times, coords)
else:
visibilities = LoadVisibilities(s, times)
visibilities *= s.convertJyToKFactor
#Prepare visibilities
visibilities /= s.convertJyToKFactor #converts to temperature units
Geometry.rephaseVisibilitiesToSnapshotCenter(s, visibilities, times)
MapMats.inverseCovarianceWeightVisibilities(s, visibilities)
#Perform mapmaking and calculate PSFs
print "Now calculating map and map statistics..."
coaddedMap = np.zeros(coords.nFacetPixels)
PSF = np.zeros((coords.nFacetPixels, coords.nPSFPixels))
pointSourcePSF = np.zeros((coords.nFacetPixels, ps.nSources))
for snapshot in times.snapshots:
print "Working on snapshot at LST = " + str(
round(snapshot.centralLST, 4)) + "..."
NinvTimesy = MapMats.calculateNinvTimesy(visibilities, snapshot)
Ninv = MapMats.calculateNInv(s, snapshot)
KAtranspose = MapMats.calculateKAtranspose(s, snapshot, coords, PBs)
coaddedMap += 2 * np.real(
np.dot(KAtranspose[coords.facetIndexLocationsInPSFIndexList, :],
NinvTimesy))
PSF += 2 * np.real(
np.dot(KAtranspose[coords.facetIndexLocationsInPSFIndexList, :],
np.dot(np.diag(Ninv),
KAtranspose.conj().transpose())))
if s.PSFforPointSources and ps.nSources > 0:
pointSourceAmatrix = MapMats.calculatePSAmatrix(
s, snapshot, ps, PBs)
pointSourcePSF += 2 * np.real(
np.dot(
KAtranspose[coords.facetIndexLocationsInPSFIndexList, :],
np.dot(np.diag(Ninv), pointSourceAmatrix)))
#Renormalize maps and PSFs and save results
#Dmatrix = np.diag(np.diag(PSF[:,coords.facetIndexLocationsInPSFIndexList])**(-1)) #This is the version I used in Dillon et al. 2015. I think the D ~ I is more logical.
Dmatrix = np.diag(
np.ones((coords.nFacetPixels)) /
PSF[coords.facetIndexOfFacetCenter, coords.PSFIndexOfFacetCenter])
PSF = np.dot(Dmatrix, PSF)
coaddedMap = np.dot(Dmatrix, coaddedMap)
mapNoiseCovariance = np.dot(
PSF[:, coords.facetIndexLocationsInPSFIndexList],
np.transpose(Dmatrix))
if s.PSFforPointSources and ps.nSources > 0:
pointSourcePSF = np.dot(Dmatrix, pointSourcePSF)
MapMats.saveAllResults(s, times, ps, Dmatrix, PSF, coaddedMap,
pointSourcePSF)
if useLogFile: sys.stdout = sys.__stdout__
return s.resultsFolder
#Dmatrix = np.diag(np.diag(PSF[:,coords.facetIndexLocationsInPSFIndexList])**(-1)) #This is the version I used in Dillon et al. 2015. I think the D ~ I is more logical.
Dmatrix = np.diag(
np.ones((coords.nFacetPixels)) /
PSF[coords.facetIndexOfFacetCenter, coords.PSFIndexOfFacetCenter])
PSF = np.dot(Dmatrix, PSF)
coaddedMap = np.dot(Dmatrix, coaddedMap)
mapNoiseCovariance = np.dot(
PSF[:, coords.facetIndexLocationsInPSFIndexList],
np.transpose(Dmatrix))
if s.PSFforPointSources and ps.nSources > 0:
pointSourcePSF = np.dot(Dmatrix, pointSourcePSF)
MapMats.saveAllResults(s, times, ps, Dmatrix, PSF, coaddedMap,
pointSourcePSF)
if useLogFile: sys.stdout = sys.__stdout__
return s.resultsFolder
if __name__ == "__main__":
mainDirectory = os.path.split(os.path.split(
os.path.abspath(__file__))[0])[0] #Directory above this one
resultsDirectory = Mapmaker(mainDirectory)
s, times, ps, Dmatrix, PSF, coaddedMap, pointSourcePSF = MapMats.loadAllResults(
resultsDirectory)
coords = Geometry.Coordinates(s)
if s.useAdaptiveHEALPixForPSF: coords.convertToAdaptiveHEALPix(s, times)
#plt.figure()
#plt.scatter(coords.PSFRAs, coords.PSFDecs, c = np.log10(np.abs(PSF[coords.facetIndexOfFacetCenter,:])), s = 1024 / coords.newPSFNSIDEs)
#plt.colorbar()
#plt.show()