def snr_check(st, threshold=3.0, min_freq=0.2, max_freq=5.0, bandwidth=20.0):
"""
Check signal-to-noise ratio.
Requires noise/singal windowing to have succeeded.
Args:
st (StationStream):
Stream of data.
threshold (float):
Threshold SNR value.
min_freq (float):
Minimum frequency for threshold to be exeeded.
max_freq (float):
Maximum frequency for threshold to be exeeded.
bandwidth (float):
Konno-Omachi smoothing bandwidth parameter.
Returns:
stream: Streams with SNR calculations and checked that they pass the
configured criteria.
"""
for tr in st:
# Comput SNR
tr = compute_snr_trace(tr, bandwidth)
if st.passed and tr.hasParameter('snr'):
snr_dict = tr.getParameter('snr')
snr = np.array(snr_dict['snr'])
freq = np.array(snr_dict['freq'])
# Check if signal criteria is met
min_snr = np.min(snr[(freq >= min_freq) & (freq <= max_freq)])
if min_snr < threshold:
tr.fail('Failed SNR check; SNR less than threshold.')
snr_conf = {
'threshold': threshold,
'min_freq': min_freq,
'max_freq': max_freq,
'bandwidth': bandwidth
}
tr.setParameter('snr_conf', snr_conf)
return st
def snr_check(st, threshold=3.0, min_freq=0.2, max_freq=5.0, bandwidth=20.0):
"""
Check signal-to-noise ratio.
Requires noise/singal windowing to have succeeded.
Args:
st (StationStream):
Stream of data.
threshold (float):
Threshold SNR value.
min_freq (float):
Minimum frequency for threshold to be exeeded.
max_freq (float):
Maximum frequency for threshold to be exeeded.
bandwidth (float):
Konno-Omachi smoothing bandwidth parameter.
Returns:
stream: Streams with SNR calculations and checked that they pass the
configured criteria.
"""
for tr in st:
# Comput SNR
tr = compute_snr_trace(tr, bandwidth)
if st.passed and tr.hasParameter('snr'):
snr_dict = tr.getParameter('snr')
snr = np.array(snr_dict['snr'])
freq = np.array(snr_dict['freq'])
# Check if signal criteria is met
min_snr = np.min(snr[(freq >= min_freq) & (freq <= max_freq)])
if min_snr < threshold:
tr.fail('Failed SNR check; SNR less than threshold.')
snr_conf = {
'threshold': threshold,
'min_freq': min_freq,
'max_freq': max_freq,
'bandwidth': bandwidth
}
tr.setParameter('snr_conf', snr_conf)
return st
def snr(st, same_horiz=True, bandwidth=20):
"""Use constant corner frequencies across all records.
Args:
st (StationStream):
Stream of data.
same_horiz (bool):
If True, horizontal traces in the stream must have the same
corner frequencies.
bandwidth (float):
Konno-Omachi smoothing bandwidth parameter.
Returns:
stream: stream with selected corner frequencies appended to records.
"""
for tr in st:
# Check for prior calculation of 'snr'
if not tr.hasCached('snr'):
tr = compute_snr_trace(tr, bandwidth)
# If it doesn't exist then it must have failed because it didn't have
# enough points in the noise or signal windows
if not tr.hasParameter('failure'):
snr_conf = tr.getParameter('snr_conf')
threshold = snr_conf['threshold']
min_freq = snr_conf['min_freq']
max_freq = snr_conf['max_freq']
if tr.hasCached('snr'):
snr_dict = tr.getCached('snr')
else:
tr.fail('Cannot use SNR to pick corners because SNR could not '
'be calculated.')
continue
snr = snr_dict['snr']
freq = snr_dict['freq']
# Loop through frequencies to find low corner and high corner
lows = []
highs = []
have_low = False
for idx, f in enumerate(freq):
if have_low is False:
if (snr[idx] >= threshold):
lows.append(f)
have_low = True
else:
continue
else:
if snr[idx] < threshold:
highs.append(f)
have_low = False
else:
continue
# If we didn't find any corners
if not lows:
tr.fail('SNR not greater than required threshold.')
continue
# If we find an extra low, add another high for the maximum
# frequency
if len(lows) > len(highs):
highs.append(max(freq))
# Check if any of the low/high pairs are valid
found_valid = False
for idx, val in enumerate(lows):
if (val <= min_freq and highs[idx] > max_freq):
low_corner = val
high_corner = highs[idx]
found_valid = True
if found_valid:
tr.setParameter(
'corner_frequencies',
{
'type': 'snr',
'highpass': low_corner,
'lowpass': high_corner
}
)
else:
tr.fail('SNR not met within the required bandwidth.')
return st
def snr(st, same_horiz=True, bandwidth=20):
"""Use constant corner frequencies across all records.
Args:
st (StationStream):
Stream of data.
same_horiz (bool):
If True, horizontal traces in the stream must have the same
corner frequencies.
bandwidth (float):
Konno-Omachi smoothing bandwidth parameter.
Returns:
stream: stream with selected corner frequencies appended to records.
"""
for tr in st:
# Check for prior calculation of 'snr'
if not tr.hasParameter('snr'):
tr = compute_snr_trace(tr, bandwidth)
# If it doesn't exist then it must have failed because it didn't have
# enough points in the noise or signal windows
if not tr.hasParameter('failure'):
snr_conf = tr.getParameter('snr_conf')
threshold = snr_conf['threshold']
min_freq = snr_conf['min_freq']
max_freq = snr_conf['max_freq']
if tr.hasParameter('snr'):
snr_dict = tr.getParameter('snr')
else:
tr.fail('Cannot use SNR to pick corners because SNR could not '
'be calculated.')
return tr
snr = snr_dict['snr']
freq = snr_dict['freq']
# Loop through frequencies to find low corner and high corner
lows = []
highs = []
have_low = False
for idx, f in enumerate(freq):
if have_low is False:
if (snr[idx] >= threshold):
lows.append(f)
have_low = True
else:
continue
else:
if snr[idx] < threshold:
highs.append(f)
have_low = False
else:
continue
# If we didn't find any corners
if not lows:
tr.fail('SNR not greater than required threshold.')
return tr
# If we find an extra low, add another high for the maximum
# frequency
if len(lows) > len(highs):
highs.append(max(freq))
# Check if any of the low/high pairs are valid
found_valid = False
for idx, val in enumerate(lows):
if (val <= min_freq and highs[idx] > max_freq):
low_corner = val
high_corner = highs[idx]
found_valid = True
if found_valid:
tr.setParameter(
'corner_frequencies',
{
'type': 'snr',
'highpass': low_corner,
'lowpass': high_corner
}
)
else:
tr.fail('SNR not met within the required bandwidth.')
return st