Export Seismograms to ASCII
Built-in Formats
You may directly export waveform data to any ASCII format available by ObsPy
using the write()
method on the generated
Stream
object.
>>> from obspy.core import read
>>> stream = read('https://examples.obspy.org/RJOB20090824.ehz')
>>> stream.write('outfile.ascii', format='SLIST')
The following ASCII formats are currently supported:
SLIST
, a ASCII time series format represented with a header line followed by a sample lists (see alsoSLIST format description
):TIMESERIES BW_RJOB__EHZ_D, 6001 samples, 200 sps, 2009-08-24T00:20:03.000000, SLIST, INTEGER, 288 300 292 285 265 287 279 250 278 278 268 258 ...
TSPAIR
, a ASCII format where data is written in time-sample pairs (see alsoTSPAIR format description
):TIMESERIES BW_RJOB__EHZ_D, 6001 samples, 200 sps, 2009-08-24T00:20:03.000000, TSPAIR, INTEGER, 2009-08-24T00:20:03.000000 288 2009-08-24T00:20:03.005000 300 2009-08-24T00:20:03.010000 292 2009-08-24T00:20:03.015000 285 2009-08-24T00:20:03.020000 265 2009-08-24T00:20:03.025000 287 ...
SH_ASC
, ASCII format supported by Seismic Handler:DELTA: 5.000000e-03 LENGTH: 6001 START: 24-AUG-2009_00:20:03.000 COMP: Z CHAN1: E CHAN2: H STATION: RJOB CALIB: 1.000000e+00 2.880000e+02 3.000000e+02 2.920000e+02 2.850000e+02 2.650000e+02 2.870000e+02 2.790000e+02 2.500000e+02 ...
Custom Format
In the following, a small Python script is shown which converts each
Trace
of a seismogram file to an ASCII file with
a custom header. Waveform data will be multiplied by a given calibration
factor and written using NumPy’s savetxt()
function.
"""
USAGE: export_seismograms_to_ascii.py in_file out_file calibration
"""
from __future__ import print_function
import sys
import numpy as np
import obspy
try:
in_file = sys.argv[1]
out_file = sys.argv[2]
calibration = float(sys.argv[3])
except Exception:
print(__doc__)
raise
st = obspy.read(in_file)
for i, tr in enumerate(st):
f = open("%s_%d" % (out_file, i), "w")
f.write("# STATION %s\n" % (tr.stats.station))
f.write("# CHANNEL %s\n" % (tr.stats.channel))
f.write("# START_TIME %s\n" % (str(tr.stats.starttime)))
f.write("# SAMP_FREQ %f\n" % (tr.stats.sampling_rate))
f.write("# NDAT %d\n" % (tr.stats.npts))
np.savetxt(f, tr.data * calibration, fmt="%f")
f.close()