marcel/pylot
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Implemented correction for attenuation in calcsourcespek.

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This commit is contained in:
Ludger Küperkoch 2015-12-04 16:05:53 +01:00
parent 28276d1f8c
commit 0c7c5645b6
1 changed files with 32 additions and 10 deletions
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42
pylot/core/analysis/magnitude.py
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@ -23,7 +23,7 @@ class Magnitude(object):
''' '''
def __init__(self, wfstream, To, pwin, iplot, NLLocfile=None, \ def __init__(self, wfstream, To, pwin, iplot, NLLocfile=None, \
picks=None, rho=None, vp=None, invdir=None): picks=None, rho=None, vp=None, Qp=None, invdir=None):
''' '''
:param: wfstream :param: wfstream
:type: `~obspy.core.stream.Stream :type: `~obspy.core.stream.Stream
@ -66,6 +66,7 @@ class Magnitude(object):
self.setrho(rho) self.setrho(rho)
self.setpicks(picks) self.setpicks(picks)
self.setvp(vp) self.setvp(vp)
self.setQp(Qp)
self.setinvdir(invdir) self.setinvdir(invdir)
self.calcwapp() self.calcwapp()
self.calcsourcespec() self.calcsourcespec()
@ -114,6 +115,12 @@ class Magnitude(object):
def getvp(self): def getvp(self):
return self.vp return self.vp
def setQp(self, Qp):
self.Qp = Qp
def getQp(self):
return self.Qp
def setpicks(self, picks): def setpicks(self, picks):
self.picks = picks self.picks = picks
@ -233,7 +240,8 @@ class M0Mw(Magnitude):
# call subfunction to estimate source spectrum # call subfunction to estimate source spectrum
# and to derive w0 and fc # and to derive w0 and fc
[w0, fc] = calcsourcespec(selwf, picks[key]['P']['mpp'], \ [w0, fc] = calcsourcespec(selwf, picks[key]['P']['mpp'], \
self.getinvdir(), az, inc, self.getiplot()) self.getinvdir(), az, inc, self.getQp(), \
self.getiplot())
if w0 is not None: if w0 is not None:
# call subfunction to calculate Mo and Mw # call subfunction to calculate Mo and Mw
@ -278,7 +286,7 @@ def calcMoMw(wfstream, w0, rho, vp, delta, inv):
def calcsourcespec(wfstream, onset, inventory, azimuth, incidence, iplot): def calcsourcespec(wfstream, onset, inventory, azimuth, incidence, Qp, iplot):
''' '''
Subfunction to calculate the source spectrum and to derive from that the plateau Subfunction to calculate the source spectrum and to derive from that the plateau
(usually called omega0) and the corner frequency assuming Aki's omega-square (usually called omega0) and the corner frequency assuming Aki's omega-square
@ -288,6 +296,13 @@ def calcsourcespec(wfstream, onset, inventory, azimuth, incidence, iplot):
''' '''
print ("Calculating source spectrum ....") print ("Calculating source spectrum ....")
# get Q value
qu = Qp.split('f**')
# constant Q
Q = int(qu[0])
# A, i.e. power of frequency
A = float(qu[1])
fc = None fc = None
w0 = None w0 = None
data = Data() data = Data()
@ -392,24 +407,26 @@ def calcsourcespec(wfstream, onset, inventory, azimuth, incidence, iplot):
fi = np.where((f >= 1) & (f < 100)) fi = np.where((f >= 1) & (f < 100))
F = f[fi] F = f[fi]
YY = Y[fi] YY = Y[fi]
# correction for attenuation
YYcor = YY.real*Q**A
# get plateau (DC value) and corner frequency # get plateau (DC value) and corner frequency
# initial guess of plateau # initial guess of plateau
w0in = np.mean(YY[0:100]) w0in = np.mean(YYcor[0:100])
# initial guess of corner frequency # initial guess of corner frequency
# where spectral level reached 50% of flat level # where spectral level reached 50% of flat level
iin = np.where(YY >= 0.5 * w0in) iin = np.where(YYcor >= 0.5 * w0in)
Fcin = F[iin[0][np.size(iin) - 1]] Fcin = F[iin[0][np.size(iin) - 1]]
# use of implicit scipy otimization function # use of implicit scipy otimization function
fit = synthsourcespec(F, w0in, Fcin) fit = synthsourcespec(F, w0in, Fcin)
[optspecfit, pcov] = curve_fit(synthsourcespec, F, YY.real, [w0in, Fcin]) [optspecfit, pcov] = curve_fit(synthsourcespec, F, YYcor, [w0in, Fcin])
w01 = optspecfit[0] w01 = optspecfit[0]
fc1 = optspecfit[1] fc1 = optspecfit[1]
print ("calcsourcespec: Determined w0-value: %e m/Hz, \n" print ("calcsourcespec: Determined w0-value: %e m/Hz, \n"
"Determined corner frequency: %f Hz" % (w01, fc1)) "Determined corner frequency: %f Hz" % (w01, fc1))
# use of conventional fitting # use of conventional fitting
[w02, fc2] = fitSourceModel(F, YY.real, Fcin, iplot) [w02, fc2] = fitSourceModel(F, YYcor, Fcin, iplot)
# get w0 and fc as median # get w0 and fc as median
w0 = np.median([w01, w02]) w0 = np.median([w01, w02])
@ -440,10 +457,15 @@ def calcsourcespec(wfstream, onset, inventory, azimuth, incidence, iplot):
if plotflag == 1: if plotflag == 1:
plt.subplot(2,1,2) plt.subplot(2,1,2)
plt.loglog(f, Y.real, 'k') p1, = plt.loglog(f, Y.real, 'k')
plt.loglog(F, YY.real) p2, = plt.loglog(F, YY.real)
plt.loglog(F, fit, 'g') p3, = plt.loglog(F, YYcor, 'r')
p4, = plt.loglog(F, fit, 'g')
plt.loglog([fc, fc], [w0/100, w0], 'g') plt.loglog([fc, fc], [w0/100, w0], 'g')
plt.legend([p1, p2, p3, p4], ['Raw Spectrum', \
'Used Raw Spectrum', \
'Q-Corrected Spectrum', \
'Fit to Spectrum'])
plt.title('Source Spectrum from P Pulse, w0=%e m/Hz, fc=%6.2f Hz' \ plt.title('Source Spectrum from P Pulse, w0=%e m/Hz, fc=%6.2f Hz' \
% (w0, fc)) % (w0, fc))
plt.xlabel('Frequency [Hz]') plt.xlabel('Frequency [Hz]')