Extended class MoMw for calculating source spectrum. New functions calcsourcespec, calcMoMw and run_calcMoMw implemented.
This commit is contained in:
Ludger Küperkoch
parent
40f38ebf84
commit
46cbe96a43
@ -8,10 +8,12 @@ Created August/September 2015.
|
||||
|
||||
import matplotlib.pyplot as plt
|
||||
import numpy as np
|
||||
from obspy.core import Stream
|
||||
from pylot.core.pick.utils import getsignalwin
|
||||
from obspy.core import Stream, UTCDateTime
|
||||
from pylot.core.pick.utils import getsignalwin, crossings_nonzero_all
|
||||
from pylot.core.util.utils import getPatternLine
|
||||
from scipy.optimize import curve_fit
|
||||
from scipy import integrate
|
||||
from pylot.core.read.data import Data
|
||||
|
||||
class Magnitude(object):
|
||||
'''
|
||||
@ -20,7 +22,8 @@ class Magnitude(object):
|
||||
and moment magnitudes.
|
||||
'''
|
||||
|
||||
def __init__(self, wfstream, To, pwin, iplot, NLLocfile=None, picks=None, rho=None, vp=None):
|
||||
def __init__(self, wfstream, To, pwin, iplot, NLLocfile=None, \
|
||||
picks=None, rho=None, vp=None, invdir=None):
|
||||
'''
|
||||
:param: wfstream
|
||||
:type: `~obspy.core.stream.Stream
|
||||
@ -30,7 +33,7 @@ class Magnitude(object):
|
||||
|
||||
:param: pwin, pick window [To To+pwin] to get maximum
|
||||
peak-to-peak amplitude (WApp) or to calculate
|
||||
source spectrum (DCfc)
|
||||
source spectrum (DCfc) around P onset
|
||||
:type: float
|
||||
|
||||
:param: iplot, no. of figure window for plotting interims results
|
||||
@ -48,6 +51,9 @@ class Magnitude(object):
|
||||
|
||||
:param: vp [m/s], P-velocity
|
||||
:param: integer
|
||||
|
||||
:param: invdir, path to inventory or dataless-SEED file
|
||||
:type: string
|
||||
'''
|
||||
|
||||
assert isinstance(wfstream, Stream), "%s is not a stream object" % str(wfstream)
|
||||
@ -60,6 +66,7 @@ class Magnitude(object):
|
||||
self.setrho(rho)
|
||||
self.setpicks(picks)
|
||||
self.setvp(vp)
|
||||
self.setinvdir(invdir)
|
||||
self.calcwapp()
|
||||
self.calcsourcespec()
|
||||
self.run_calcMoMw()
|
||||
@ -122,6 +129,12 @@ class Magnitude(object):
|
||||
def getfc(self):
|
||||
return self.fc
|
||||
|
||||
def setinvdir(self, invdir):
|
||||
self.invdir = invdir
|
||||
|
||||
def getinvdir(self):
|
||||
return self.invdir
|
||||
|
||||
def getpicdic(self):
|
||||
return self.picdic
|
||||
|
||||
@ -190,7 +203,8 @@ class M0Mw(Magnitude):
|
||||
Requires results of class w0fc for calculating plateau w0
|
||||
and corner frequency fc of source spectrum, respectively. Uses
|
||||
subfunction calcMoMw.py. Returns modified dictionary of picks including
|
||||
seismic moment Mo and corresponding moment magntiude Mw.
|
||||
Dc-value, corner frequency fc, seismic moment Mo and
|
||||
corresponding moment magntiude Mw.
|
||||
'''
|
||||
|
||||
def run_calcMoMw(self):
|
||||
@ -198,12 +212,15 @@ class M0Mw(Magnitude):
|
||||
picks = self.getpicks()
|
||||
nllocfile = self.getNLLocfile()
|
||||
wfdat = self.getwfstream()
|
||||
# get vertical component data only
|
||||
zdat = wfdat.select(component="Z")
|
||||
if len(zdat) == 0: # check for other components
|
||||
zdat = wfdat.select(component="3")
|
||||
|
||||
for key in picks:
|
||||
if picks[key]['P']['weight'] < 4 and picks[key]['P']['w0'] is not None:
|
||||
if picks[key]['P']['weight'] < 4:
|
||||
# select waveform
|
||||
selwf = wfdat.select(station=key)
|
||||
# get corresponding height of source spectrum plateau w0
|
||||
w0 = picks[key]['P']['w0']
|
||||
selwf = zdat.select(station=key)
|
||||
# get hypocentral distance of station
|
||||
# from NLLoc-location file
|
||||
if len(key) > 4:
|
||||
@ -214,14 +231,27 @@ class M0Mw(Magnitude):
|
||||
Ppattern = '%s ? ? ? P' % key
|
||||
nllocline = getPatternLine(nllocfile, Ppattern)
|
||||
delta = float(nllocline.split(None)[21])
|
||||
# call subfunction
|
||||
[Mo, Mw] = calcMoMw(selwf, w0, self.getrho(), self.getvp(), delta)
|
||||
# add Mo and Mw to dictionary
|
||||
# call subfunction to estimate source spectrum
|
||||
# and to derive w0 and fc
|
||||
[w0, fc] = calcsourcespec(selwf, picks[key]['P']['mpp'], \
|
||||
self.getiplot(), self.getinvdir())
|
||||
|
||||
if w0 is not None:
|
||||
# call subfunction to calculate Mo and Mw
|
||||
[Mo, Mw] = calcMoMw(selwf, w0, self.getrho(), self.getvp(), \
|
||||
delta, self.getinvdir())
|
||||
else:
|
||||
Mo = None
|
||||
Mw = None
|
||||
|
||||
# add w0, fc, Mo and Mw to dictionary
|
||||
picks[key]['P']['w0'] = w0
|
||||
picks[key]['P']['fc'] = fc
|
||||
picks[key]['P']['Mo'] = Mo
|
||||
picks[key]['P']['Mw'] = Mw
|
||||
self.picdic = picks
|
||||
|
||||
def calcMoMw(wfstream, w0, rho, vp, delta):
|
||||
def calcMoMw(wfstream, w0, rho, vp, delta, inv):
|
||||
'''
|
||||
Subfunction of run_calcMoMw to calculate individual
|
||||
seismic moments and corresponding moment magnitudes.
|
||||
@ -245,94 +275,135 @@ def calcMoMw(wfstream, w0, rho, vp, delta):
|
||||
return Mo, Mw
|
||||
|
||||
|
||||
class w0fc(Magnitude):
|
||||
|
||||
def calcsourcespec(wfstream, onset, iplot, inventory):
|
||||
'''
|
||||
Method 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
|
||||
source model. Has to be derived from instrument corrected displacement traces!
|
||||
source model. Has to be derived from instrument corrected displacement traces,
|
||||
thus restitution and integration necessary!
|
||||
'''
|
||||
print ("Calculating source spectrum ....")
|
||||
|
||||
def calcsourcespec(self):
|
||||
print ("Calculating source spectrum ....")
|
||||
fc = None
|
||||
w0 = None
|
||||
data = Data()
|
||||
z_copy = wfstream.copy()
|
||||
|
||||
self.w0 = None # DC-value
|
||||
self.fc = None # corner frequency
|
||||
|
||||
stream = self.getwfstream()
|
||||
tr = stream[0]
|
||||
[corzdat, restflag] = data.restituteWFData(inventory, z_copy)
|
||||
|
||||
if restflag == 1:
|
||||
# integrate to displacment
|
||||
corintzdat = integrate.cumtrapz(corzdat[0], None, corzdat[0].stats.delta)
|
||||
z_copy[0].data = corintzdat
|
||||
tr = z_copy[0]
|
||||
# get window after P pulse for
|
||||
# calculating source spectrum
|
||||
if tr.stats.sampling_rate <= 100:
|
||||
winzc = tr.stats.sampling_rate
|
||||
elif tr.stats.sampling_rate > 100 and \
|
||||
tr.stats.sampling_rate <= 200:
|
||||
winzc = 0.5 * tr.stats.sampling_rate
|
||||
elif tr.stats.sampling_rate > 200 and \
|
||||
tr.stats.sampling_rate <= 400:
|
||||
winzc = 0.2 * tr.stats.sampling_rate
|
||||
elif tr.stats.sampling_rate > 400:
|
||||
winzc = tr.stats.sampling_rate
|
||||
tstart = UTCDateTime(tr.stats.starttime)
|
||||
tonset = onset.timestamp -tstart.timestamp
|
||||
impickP = tonset * tr.stats.sampling_rate
|
||||
wfzc = tr.data[impickP : impickP + winzc]
|
||||
# get time array
|
||||
t = np.arange(0, len(tr) * tr.stats.delta, tr.stats.delta)
|
||||
iwin = getsignalwin(t, self.getTo(), self.getpwin())
|
||||
xdat = tr.data[iwin]
|
||||
# calculate spectrum using only first cycles of
|
||||
# waveform after P onset!
|
||||
zc = crossings_nonzero_all(wfzc)
|
||||
if np.size(zc) == 0 or len(zc) <= 3:
|
||||
print ("Something is wrong with the waveform, "
|
||||
"no zero crossings derived!")
|
||||
print ("No calculation of source spectrum possible!")
|
||||
plotflag = 0
|
||||
else:
|
||||
plotflag = 1
|
||||
index = min([3, len(zc) - 1])
|
||||
calcwin = (zc[index] - zc[0]) * z_copy[0].stats.delta
|
||||
iwin = getsignalwin(t, tonset, calcwin)
|
||||
xdat = tr.data[iwin]
|
||||
|
||||
# fft
|
||||
fny = tr.stats.sampling_rate / 2
|
||||
l = len(xdat) / tr.stats.sampling_rate
|
||||
n = tr.stats.sampling_rate * l # number of fft bins after Bath
|
||||
# find next power of 2 of data length
|
||||
m = pow(2, np.ceil(np.log(len(xdat)) / np.log(2)))
|
||||
N = int(np.power(m, 2))
|
||||
y = tr.stats.delta * np.fft.fft(xdat, N)
|
||||
Y = abs(y[: N/2])
|
||||
L = (N - 1) / tr.stats.sampling_rate
|
||||
f = np.arange(0, fny, 1/L)
|
||||
# fft
|
||||
fny = tr.stats.sampling_rate / 2
|
||||
l = len(xdat) / tr.stats.sampling_rate
|
||||
n = tr.stats.sampling_rate * l # number of fft bins after Bath
|
||||
# find next power of 2 of data length
|
||||
m = pow(2, np.ceil(np.log(len(xdat)) / np.log(2)))
|
||||
N = int(np.power(m, 2))
|
||||
y = tr.stats.delta * np.fft.fft(xdat, N)
|
||||
Y = abs(y[: N/2])
|
||||
L = (N - 1) / tr.stats.sampling_rate
|
||||
f = np.arange(0, fny, 1/L)
|
||||
|
||||
# remove zero-frequency and frequencies above
|
||||
# corner frequency of seismometer (assumed
|
||||
# to be 100 Hz)
|
||||
fi = np.where((f >= 1) & (f < 100))
|
||||
F = f[fi]
|
||||
YY = Y[fi]
|
||||
# get plateau (DC value) and corner frequency
|
||||
# initial guess of plateau
|
||||
w0in = np.mean(YY[0:100])
|
||||
# initial guess of corner frequency
|
||||
# where spectral level reached 50% of flat level
|
||||
iin = np.where(YY >= 0.5 * w0in)
|
||||
Fcin = F[iin[0][np.size(iin) - 1]]
|
||||
# remove zero-frequency and frequencies above
|
||||
# corner frequency of seismometer (assumed
|
||||
# to be 100 Hz)
|
||||
fi = np.where((f >= 1) & (f < 100))
|
||||
F = f[fi]
|
||||
YY = Y[fi]
|
||||
# get plateau (DC value) and corner frequency
|
||||
# initial guess of plateau
|
||||
w0in = np.mean(YY[0:100])
|
||||
# initial guess of corner frequency
|
||||
# where spectral level reached 50% of flat level
|
||||
iin = np.where(YY >= 0.5 * w0in)
|
||||
Fcin = F[iin[0][np.size(iin) - 1]]
|
||||
|
||||
# use of implicit scipy otimization function
|
||||
fit = synthsourcespec(F, w0in, Fcin)
|
||||
[optspecfit, pcov] = curve_fit(synthsourcespec, F, YY.real, [w0in, Fcin])
|
||||
w01 = optspecfit[0]
|
||||
fc1 = optspecfit[1]
|
||||
print ("w0fc: Determined w0-value: %e m/Hz, \n"
|
||||
"Determined corner frequency: %f Hz" % (w01, fc1))
|
||||
# use of implicit scipy otimization function
|
||||
fit = synthsourcespec(F, w0in, Fcin)
|
||||
[optspecfit, pcov] = curve_fit(synthsourcespec, F, YY.real, [w0in, Fcin])
|
||||
w01 = optspecfit[0]
|
||||
fc1 = optspecfit[1]
|
||||
print ("w0fc: Determined w0-value: %e m/Hz, \n"
|
||||
"Determined corner frequency: %f Hz" % (w01, fc1))
|
||||
|
||||
# use of conventional fitting
|
||||
[w02, fc2] = fitSourceModel(F, YY.real, Fcin, self.getiplot())
|
||||
# use of conventional fitting
|
||||
[w02, fc2] = fitSourceModel(F, YY.real, Fcin, iplot)
|
||||
|
||||
# get w0 and fc as median
|
||||
self.w0 = np.median([w01, w02])
|
||||
self.fc = np.median([fc1, fc2])
|
||||
print("w0fc: Using w0-value = %e m/Hz and fc = %f Hz" % (self.w0, self.fc))
|
||||
# get w0 and fc as median
|
||||
w0 = np.median([w01, w02])
|
||||
fc = np.median([fc1, fc2])
|
||||
print("w0fc: Using w0-value = %e m/Hz and fc = %f Hz" % (w0, fc))
|
||||
|
||||
if self.getiplot() > 1:
|
||||
f1 = plt.figure()
|
||||
plt.subplot(2,1,1)
|
||||
# show displacement in mm
|
||||
plt.plot(t, np.multiply(tr, 1000), 'k')
|
||||
if iplot > 1:
|
||||
f1 = plt.figure()
|
||||
plt.subplot(2,1,1)
|
||||
# show displacement in mm
|
||||
plt.plot(t, np.multiply(tr, 1000), 'k')
|
||||
if plotflag == 1:
|
||||
plt.plot(t[iwin], np.multiply(xdat, 1000), 'g')
|
||||
plt.title('Seismogram and P pulse, station %s' % tr.stats.station)
|
||||
plt.xlabel('Time since %s' % tr.stats.starttime)
|
||||
plt.ylabel('Displacement [mm]')
|
||||
plt.title('Seismogram and P Pulse, Station %s-%s' \
|
||||
% (tr.stats.station, tr.stats.channel))
|
||||
else:
|
||||
plt.title('Seismogram, Station %s-%s' \
|
||||
% (tr.stats.station, tr.stats.channel))
|
||||
plt.xlabel('Time since %s' % tr.stats.starttime)
|
||||
plt.ylabel('Displacement [mm]')
|
||||
|
||||
if plotflag == 1:
|
||||
plt.subplot(2,1,2)
|
||||
plt.loglog(f, Y.real, 'k')
|
||||
plt.loglog(F, YY.real)
|
||||
plt.loglog(F, fit, 'g')
|
||||
plt.loglog([self.fc, self.fc], [self.w0/100, self.w0], 'g')
|
||||
plt.loglog([fc, fc], [w0/100, w0], 'g')
|
||||
plt.title('Source Spectrum from P Pulse, w0=%e m/Hz, fc=%6.2f Hz' \
|
||||
% (self.w0, self.fc))
|
||||
% (w0, fc))
|
||||
plt.xlabel('Frequency [Hz]')
|
||||
plt.ylabel('Amplitude [m/Hz]')
|
||||
plt.grid()
|
||||
plt.show()
|
||||
raw_input()
|
||||
plt.close(f1)
|
||||
|
||||
plt.show()
|
||||
raw_input()
|
||||
plt.close(f1)
|
||||
|
||||
return w0, fc
|
||||
|
||||
|
||||
def synthsourcespec(f, omega0, fcorner):
|
||||
'''
|
||||
|
||||
Loading…
Reference in New Issue
Block a user