def _calc_resp(calfile, nfft, sampfreq):
"""
Calculate transfer function of known system.
:type calfile: str
:param calfile: file containing poles, zeros and scale factor for known
system or a dictionary with poles and zeros information (with keys
``'poles'``, ``'zeros'`` and ``'sensitivity'``).
:returns: complex transfer function, array of frequencies
"""
# test if calfile is a paz dict
if isinstance(calfile, dict):
paz = calfile
# or read paz file if a filename is specified
else:
paz = dict()
paz['poles'], paz['zeros'], paz['sensitivity'] = read_paz(calfile)
# calculate transfer function
h, f = paz_to_freq_resp(paz['poles'],
paz['zeros'],
paz['sensitivity'],
1.0 / sampfreq,
nfft,
freq=True)
return h, f
def computeresp(resp, delta, lenfft):
respval = paz_to_freq_resp(resp['poles'],
resp['zeros'],
resp['sensitivity'] * resp['gain'],
t_samp=delta,
nfft=lenfft,
freq=False)
respval = np.absolute(respval * np.conjugate(respval))
respval = respval[1:]
return respval
def _calc_resp(calfile, nfft, sampfreq):
"""
Calculate transfer function of known system.
:type calfile: str
:param calfile: file containing poles, zeros and scale factor for known
system
:returns: complex transfer function, array of frequencies
"""
# calculate transfer function
poles, zeros, scale_fac = read_paz(calfile)
h, f = paz_to_freq_resp(poles, zeros, scale_fac, 1.0 / sampfreq, nfft, freq=True)
return h, f
def computeresp(resp, delta, lenfft):
respval, freq = paz_to_freq_resp(resp['poles'],
resp['zeros'],
resp['sensitivity'] * resp['gain'],
t_samp=delta,
nfft=lenfft,
freq=True)
idx = np.argmin(np.abs(freq - .1))
respval = np.absolute(respval * np.conjugate(respval))
respval *= 1. / respval[idx]
respval = respval[1:] * resp['sensitivity']**2
respval = respval.real
return respval
def _calc_resp(calfile, nfft, sampfreq):
"""
Calculate transfer function of known system.
:type calfile: str
:param calfile: file containing poles, zeros and scale factor for known
system
:returns: complex transfer function, array of frequencies
"""
# calculate transfer function
poles, zeros, scale_fac = read_paz(calfile)
h, f = paz_to_freq_resp(poles, zeros, scale_fac, 1.0 / sampfreq,
nfft, freq=True)
return h, f
def _calc_resp(calfile, nfft, sampfreq):
"""
Calculate transfer function of known system.
:type calfile: str
:param calfile: file containing poles, zeros and scale factor for known
system or a dictionary with poles and zeros information (with keys
``'poles'``, ``'zeros'`` and ``'sensitivity'``).
:returns: complex transfer function, array of frequencies
"""
# test if calfile is a paz dict
if isinstance(calfile, dict):
paz = calfile
# or read paz file if a filename is specified
else:
paz = dict()
paz['poles'], paz['zeros'], paz['sensitivity'] = read_paz(calfile)
# calculate transfer function
h, f = paz_to_freq_resp(paz['poles'], paz['zeros'], paz['sensitivity'],
1.0 / sampfreq, nfft, freq=True)
return h, f
def test_simple_response():
import matplotlib.pyplot as plt
try:
from obspy.signal.invsim import paz_to_freq_resp
except:
from obspy.signal.invsim import pazToFreqResp as paz_to_freq_resp
try:
from obspy.signal.invsim import paz_2_amplitude_value_of_freq_resp
except:
from obspy.signal.invsim import paz2AmpValueOfFreqResp as paz_2_amplitude_value_of_freq_resp
#{'zeros': [(-31.617+0j), 0j, 0j], 'poles': [(-0.1486-0.1486j), (-0.1486+0.1486j), (-336.766-136.656j), (-336.766+136.656j), (-47.0636+0j), (-2469.36+0j)], 'gain': 491884000.0}
N = 1024
sample_rate = 100.
normalization_frequency = 1.0
normalization_factor = 1.6
poles = [(-5.026548 + 3.769911j), (-5.026548 - 3.769911j)]
zeros = [complex(0.), complex(0.)]
amplitude, frequency = paz_to_freq_resp(poles,
zeros,
1.0,
1.0 / sample_rate,
2 * N,
freq=True)
print len(amplitude)
print np.max(amplitude)
plt.loglog(frequency, abs(amplitude), basex=10, basey=10)
plt.show()
paz = {"poles": poles, "zeros": zeros, "gain": normalization_factor}
calculated_A0 = paz_2_amplitude_value_of_freq_resp(
paz, normalization_frequency)
if abs(calculated_A0 - 1.0) > 1e-06:
print "Discrepancy, calculated normalized amplitude: {}, \
normalization factor {} at normalization frequency {}\
does not normalize the frequency spectrum." .\
format(calculated_A0, normalization_factor, normalization_frequency)
inst1 = Response(desc=instName, units='Radians')
inst1.zeros = zer1
inst1.poles = pol1
#norm_freq=0.02
norm_freq = 1.0
n1, f1 = inst1.check_normalization(freq=norm_freq, nfft=2**26, t_sample=0.001)
scale_fac = 1.0 / n1
print('The A0 norm factor is: ' + str(scale_fac) + ' for f=' + str(norm_freq))
#check the value
inst1.a0 = 1.0 / n1
A01 = inst1.a0
n, f = inst1.check_normalization(freq=norm_freq, nfft=2**26, t_sample=0.001)
print('This should be close to 1: ' + str(1.0 / n))
h1, f1 = paz_to_freq_resp(inst1.poles,
inst1.zeros,
scale_fac,
0.001,
2**26,
freq=True)
print(h1)
# and now for the second resp....
inst2 = Response(desc=instName, units='Radians')
inst2.zeros = zer2
inst2.poles = pol2
#norm_freq=0.02
norm_freq = 1.0
n2, f2 = inst2.check_normalization(freq=norm_freq, nfft=2**24, t_sample=0.001)
scale_fac = 1.0 / n2
print('The A0 norm factor is: ' + str(scale_fac) + ' for f=' + str(norm_freq))
#check the value
inst2.a0 = 1.0 / n2
inst.poles = pol
#norm_freq=0.05
#norm_freq=0.02
norm_freq = 1.0
n, f = inst.check_normalization(freq=norm_freq, nfft=2**26, t_sample=0.001)
scale_fac = 1.0 / n
print('The A0 norm factor is: ' + str(scale_fac) + ' for f=' + str(norm_freq))
#check the value
inst.a0 = 1.0 / n
n, f = inst.check_normalization(freq=norm_freq, nfft=2**26, t_sample=0.001)
print('This should be close to 1: ' + str(1.0 / n))
h, f = paz_to_freq_resp(inst.poles,
inst.zeros,
scale_fac,
0.001,
2**26,
freq=True)
plt.figure()
plt.subplot(121)
plt.semilogx(f, abs(h))
plt.xlabel('Frequency [Hz]')
plt.ylabel('Amplitude')
plt.grid(which='both', linestyle=':')
#plt.xlim([0.2,40])
plt.subplot(122)
# take negative of imaginary part
phase = np.unwrap(np.arctan2(h.imag, h.real))
plt.semilogx(f, phase)
import numpy as np
import matplotlib.pyplot as plt
from obspy.signal.invsim import paz_to_freq_resp
poles = [-4.440 + 4.440j, -4.440 - 4.440j, -1.083 + 0.0j]
zeros = [0.0 + 0.0j, 0.0 + 0.0j, 0.0 + 0.0j]
scale_fac = 0.4
h, f = paz_to_freq_resp(poles, zeros, scale_fac, 0.005, 16384, freq=True)
plt.figure()
plt.subplot(121)
plt.loglog(f, abs(h))
plt.xlabel('Frequency [Hz]')
plt.ylabel('Amplitude')
plt.subplot(122)
# take negative of imaginary part
phase = np.unwrap(np.arctan2(-h.imag, h.real))
plt.semilogx(f, phase)
plt.xlabel('Frequency [Hz]')
plt.ylabel('Phase [radian]')
# title, centered above both subplots
plt.suptitle('Frequency Response of LE-3D/1s Seismometer')
# make more room in between subplots for the ylabel of right plot
plt.subplots_adjust(wspace=0.3)
plt.show()
def plot_Freq_Amp_Phase(pltfile, paz, sName, type):
poles = paz['poles']
zeros = paz['zeros']
scale_fac = paz['gain'] * paz['seismometer_gain']
if (1000 <= type and type < 2000):
h, f = paz_to_freq_resp(poles, zeros, scale_fac, 0.005, 65536 * 8, freq=True)
elif (2000 <= type):
h, f = paz_to_freq_resp(poles, zeros, scale_fac, 0.001, 65536 * 8, freq=True)
else:
h, f = paz_to_freq_resp(poles, zeros, scale_fac, 0.001, 65536 * 8, freq=True)
font = FontProperties(fname=r"c:\windows\fonts\simsun.ttc", size=12)
fontTitle = FontProperties(fname=r"c:\windows\fonts\simsun.ttc", size=18)
plt.figure(figsize=(16, 12))
# plt.xlim(0.001, 100)
plt.subplot(211)
plt.grid(linestyle=':')
plt.loglog(f, abs(h))
plt.xlabel('频率[Hz]', fontproperties=font)
if 1000 <= type < 2000:
plt.ylabel('增益[V/(m/s)]', fontproperties=font)
elif 2000 <= type:
plt.ylabel('增益[V/(m/s**2)]', fontproperties=font)
else:
plt.ylabel('增益', fontproperties=font)
plt.subplot(212)
plt.grid(linestyle=':')
phase = np.unwrap(np.angle(h))
fTt = 0
for p0 in phase:
fTt += p0
fAver = fTt / len(phase)
if (fAver <= -np.pi):
phase += 2 * np.pi
elif (fAver > np.pi):
phase -= 2 * np.pi
import datetime
timestr = datetime.datetime.now().strftime('%Y-%m-%d')
timestr = "Created by 泰德, " + timestr
x0 = ' 频率[Hz] ' + timestr
plt.semilogx(f, phase)
# plt.xlabel('频率[Hz]',fontproperties=font)
plt.xlabel(x0, fontproperties=font)
plt.ylabel('相位[rad]', fontproperties=font)
# ticks and tick labels at multiples of pi
plt.yticks(
[-np.pi, -np.pi / 2, 0, np.pi / 2, np.pi],
[r'$-\pi$', r'$-\frac{\pi}{2}$', '$0$', r'$\frac{\pi}{2}$', r'$\pi$'])
plt.ylim(-0.2 - np.pi, np.pi + 0.2)
# title, centered above both subplots
if (1000 <= type and type < 2000):
plt.suptitle('%s 地震计幅频相频响应' % (sName), fontproperties=fontTitle)
elif (2000 <= type):
plt.suptitle('%s 加速度计幅频相频响应' % (sName), fontproperties=fontTitle)
else:
plt.suptitle('仪器 %s 幅频相频响应' % (sName), fontproperties=fontTitle)
# import datetime
# timestr = datetime.datetime.now().strftime('%Y-%m-%d')
# timestr = "Created by TAIDE, " + timestr
# plt.text(10.6,-4.2,timestr,fontsize=12)
# make more room in between subplots for the ylabel of right plot
plt.subplots_adjust(wspace=0.1)
plt.savefig(pltfile)
plt.close('all')
# We can do the same thing for an STS-1 response
paz2 = {
'gain':
3948.58,
'zeros': [0, 0],
'poles': [
-0.01234 - 0.01234j, -0.01234 + 0.01234j, -39.18 - 49.12j,
-39.18 + 49.12j
],
'sensitivity':
3.3554432 * 10**9
}
respval = paz_to_freq_resp(paz2['poles'],
paz2['zeros'],
paz2['sensitivity'],
t_samp=1. / sampling_rate,
nfft=lenfft,
freq=False)
respval = np.absolute(respval * np.conjugate(respval))
respval = respval[1:]
respval = respval / respval[1]
AerrSTS1 = 10. * np.log10(((AS * AE * (respval))**2) / freq)
fig = plt.figure(1)
plt.subplot(2, 1, 1)
plt.semilogx(perNLNM, NLNM, label='NLNM/NHNM', color='.7', linewidth=2.)
plt.semilogx(perNHNM, NHNM, color='.7', linewidth=2.)
plt.semilogx(1. / freq,
A,
label='Brune Spectra Mw=' + str(Mw) + ' at ' + str(Rrs / 1000.) +
paz2['gain'] = 1. / paz_2_amplitude_value_of_freq_resp(paz2, .1)
# this is from sensor test suite
paz3 = {
'zeros': [0.000000E+00 + 0.000000E+00j, 0.000000E+00 + 0.000000E+00j],
'poles': [
-1.263000E-02 + 1.265000E-02j, -1.263000E-02 + -1.265000E-02j,
-3.620107E+01 + 6.850121E+01j, -3.620107E+01 + -6.850121E+01j
],
'gain':
1
}
paz3['gain'] = 1. / paz_2_amplitude_value_of_freq_resp(paz3, .1)
h1, f1 = paz_to_freq_resp(paz1['poles'],
paz1['zeros'],
paz1['gain'],
1. / 200.,
2**18,
freq=True)
h2, f2 = paz_to_freq_resp(paz2['poles'],
paz2['zeros'],
paz2['gain'],
1. / 200.,
2**18,
freq=True)
h3, f3 = paz_to_freq_resp(paz3['poles'],
paz3['zeros'],
paz3['gain'],
1. / 200.,
2**18,
freq=True)
#plotting....
def _get_response_from_paz_dict(self, tr):
paz = self.metadata
resp = paz_to_freq_resp(paz['poles'], paz['zeros'],
paz['gain'] * paz['sensitivity'],
self.delta, nfft=self.nfft)
return resp
norm_freq = 1.0
#define the poles and zeros.
#tr-120 NRL paz
pol = [-32.55, -142, -364 + 404j, -364 - 404j]
zer = [-31.63, -350]
instName = 'TR120 NRL high-f paz'
inst = Response(desc=instName, units='Radians')
inst.zeros = zer
inst.poles = pol
n, f = inst.check_normalization(freq=norm_freq, nfft=2**26, t_sample=0.001)
scale_fac = 1.0 / n
h1, f1 = paz_to_freq_resp(inst.poles,
inst.zeros,
scale_fac,
0.001,
2**26,
freq=True)
#tr-120 one high-f cal signal
pol = [-28.15385, -146.36053, -313.52396 - 429.04933j, -313.52396 + 429.04933j]
zer = [-27.63939, -467.15426]
instName = 'TR120 one high-f paz'
inst = Response(desc=instName, units='Radians')
inst.zeros = zer
inst.poles = pol
n, f = inst.check_normalization(freq=norm_freq, nfft=2**26, t_sample=0.001)
scale_fac = 1.0 / n
h2, f2 = paz_to_freq_resp(inst.poles,
inst.zeros,
scale_fac,
def simple_response(sample_rate, response):
"""
Given the obspy ResponseStages, calculate the simple response.
i.e. the natural frequency, damping factor, low corner, high corner, and overall gain
"""
EPSILON = 5e-02 # tolerance for normalized amplitude of a pole-zero stage being off from 1.0
NFREQ = 2048 # number of frequency points to calculate amplitude spectrum for.
delta_t = 1.0 / sample_rate
poles = []
zeros = []
# take the normalization frequency from the InstrumentSensitivity
normalization_frequency = response.instrument_sensitivity.frequency
signal_input_units = response.instrument_sensitivity.input_units
# Gather all the poles and zeros, and the stage gains.
total_gain = 1
for stage in response.response_stages:
if hasattr(stage, "stage_gain"):
stage_gain = stage.stage_gain
if hasattr(stage, "zeros"):
zeros.extend(stage.zeros)
if hasattr(stage, "poles"):
poles.extend(stage.poles)
# check if normalization factor is correct
paz = {
"poles": stage.poles,
"zeros": stage.zeros,
"gain": stage.normalization_factor
}
calculated_amplitude = paz_2_amplitude_value_of_freq_resp(
paz, stage.normalization_frequency)
if np.abs(calculated_amplitude - 1.0) > EPSILON:
logging.warning("Warning: normalized amplitude at normalization frequency is {}, i.e. {:6.3f}% from 1,\
using calculated gain value {:5.2f} vs {:5.2f} instead" .\
format(calculated_amplitude, 100*(calculated_amplitude-1)/1,calculated_amplitude*stage.stage_gain, stage.stage_gain))
stage_gain = calculated_amplitude * stage.stage_gain
total_gain = total_gain * stage_gain
# log a warning if the total_gain is not similar to the reported instrument_sensitivity
if np.abs((total_gain - response.instrument_sensitivity.value) /
response.instrument_sensitivity.value) > EPSILON:
logging.warning("Warning: Reported sensitivity: {:5.2f}, \
Calculated sensitivity: {:5.2f}" . \
format(response.instrument_sensitivity.value, total_gain))
# calculate overall normalization factor at normalization frequency
paz = {"poles": poles, "zeros": zeros, "gain": 1.0}
calculated_amplitude = paz_2_amplitude_value_of_freq_resp(
paz, normalization_frequency)
normalization_factor = 1.0 / calculated_amplitude
# calculate the normalized frequency spectrum at NFREQ frequency points
amplitude, frequency = paz_to_freq_resp(poles,
zeros,
normalization_factor,
delta_t,
2 * NFREQ,
freq=True)
# determine the high and low frequency corners from the amplitude spectrum
logging.debug("Determining frequency corners")
f_hp, f_lp = compute_corners(amplitude, frequency)
logging.debug(("f_hp: {}, f_lp: {}").format(f_hp, f_lp))
# velocity transducer or acceleration?
if signal_input_units == "M/S" or signal_input_units == "M":
sensor_type = "VEL"
else:
sensor_type = "ACC"
# try to determine natural frequency and damping factor from poles and corners
logging.debug("Determining natural frequency and damping factor")
natural_frequency, damping = natural_frequency_and_damping(
poles, f_hp, f_lp, sensor_type=sensor_type)
logging.debug(("fn: {}, damp: {}").format(natural_frequency, damping))
# some sanity checks, limit f_lp to 40% of Nyquist, f_hp must be <= f_lp
if f_lp > 0.4 * sample_rate:
f_lp = 0.4 * sample_rate
if f_hp > f_lp:
f_hp = f_lp
return natural_frequency, damping, f_hp, f_lp, total_gain
sens = []
for sta in stas:
f = open('Results_Swept_Sine' + sta, 'r')
for line in f:
line = line.split(',')
fs.append(float(line[4]))
hs.append(float(line[5]))
sens.append(float(line[6]))
chans.append(line[0])
f.close()
#####################################################Make mean
for triple in zip(fs, hs, sens):
paz = corn_freq_2_paz(triple[0], triple[1])
h, f = paz_to_freq_resp(paz['poles'], paz['zeros'], 1., 1. / 1000., 2**14,
True)
h *= triple[2]
if 'hmean' not in vars():
hmean = h
else:
hmean += h
hmean *= 1. / 9.
fig = plt.figure(1, figsize=(12, 12))
ax = fig.add_subplot(111)
plt.subplots_adjust(hspace=0.001)
for idx, quad in enumerate(zip(chans, fs, hs, sens)):
if quad[0] == 'HHZ':
color = 'C0'
elif quad[0] == 'HHN':
f, p2 = signal.welch(tr.data,
fs=tr.stats.sampling_rate,
nperseg=NFFT,
noverlap=1024)
f = f[1:]
p2 = p2[1:]
if 'p' in vars():
p = np.vstack((p, p2))
else:
p = p2
p = np.mean(p, axis=0)
Tfnom, fnom = paz_to_freq_resp(sts6paz.poles,
sts6paz.zeros,
sts6paz.stage_gain *
sts6paz.normalization_factor,
1. / st[0].stats.sampling_rate,
NFFT,
freq=True)
Tfnom = Tfnom[1:] * (2**26) / 40.
plt.semilogx(1. / f,
10. * np.log10(p / np.abs(Tfnom)**2),
label='Q330HR Noise with STS-6 Response')
Tfnom, fnom = paz_to_freq_resp(sts2paz.poles,
sts2paz.zeros,
sts2paz.stage_gain *
sts2paz.normalization_factor,
1. / st[0].stats.sampling_rate,
NFFT,
freq=True)
Tfnom = Tfnom[1:] * (2**26) / 40.
# create list of stations
stationList = list(set([tr.stats.station for tr in st.traces]))
# define PAZ values for transfer function
# example with Lennartz 3D/5s instruments
LEpoles = [(-0.888 + 0.888j), (-0.888 - 0.888j), (-0.29 + 0j)]
LEzeros = [0j, 0j, 0j]
LEscale = 400.0
sampfreq = 100.
nfft = 4096
# maybe 4096 (adjust also in psd and csd) to get more long period spectrum
# calculate transfer function
T1 = paz_to_freq_resp(LEpoles,
LEzeros,
LEscale,
1.0 / sampfreq,
nfft,
freq=True)
# iterate over each station combination
for stat1 in stationList:
for stat2 in stationList:
if stat1 == stat2:
continue
# select traces
st1 = st.select(station=stat1)
st2 = st.select(station=stat2)
# calculate power spectral density and cross-spectrum
def _get_response_from_paz_dict(self, tr):
paz = self.metadata
resp = paz_to_freq_resp(paz['poles'], paz['zeros'],
paz['gain'] * paz['sensitivity'],
self.delta, nfft=self.nfft)
return resp
