DataAnalysis2022/ObsPy/04_Station_metainformation.ipynb

ObsPy Tutorial

Handling Station Metadata

Seismo-Live: http://seismo-live.org

Authors:

• Lion Krischer (@krischer)
• Tobias Megies (@megies)

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%matplotlib inline
import matplotlib.pyplot as plt
plt.style.use('ggplot')
plt.rcParams['figure.figsize'] = 12, 8

• for station metadata, the de-facto standard of the future (replacing SEED/RESP) is FDSN StationXML
• FDSN StationXML files can be read using read_inventory()

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from obspy import read_inventory
# real-world StationXML files often deviate from the official schema definition
# therefore file-format autodiscovery sometimes fails and we have to force the file format
inventory = read_inventory("./data/station_PFO.xml", format="STATIONXML")
print(type(inventory))

• the nested ObsPy Inventory class structure (Inventory/Station/Channel/Response/...) is closely modelled after FDSN StationXML

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!head data/station_BFO.xml

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print(inventory)

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network = inventory[0]
print(network)

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station = network[0]
print(station)

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channel = station[0]
print(channel)

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print(channel.response)

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from obspy import read
st = read("./data/waveform_PFO.mseed")
print(st)

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inv = read_inventory("./data/station_PFO.xml", format="STATIONXML")

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print(st[0].stats)

• the instrument response can be deconvolved from the waveform data using the convenience method Stream.remove_response()
• evalresp is used internally to calculate the instrument response

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st.plot()
st.remove_response(inventory=inv)
st.plot()

• several options can be used to specify details of the deconvolution (water level, frequency domain prefiltering), output units (velocity/displacement/acceleration), demeaning, tapering and to specify if any response stages should be omitted

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st = read("./data/waveform_PFO.mseed")
st.remove_response(inventory=inv, water_level=60, pre_filt=(0.01, 0.02, 8, 10), output="DISP")
st.plot()

• station metadata not present in StationXML yet but in Dataless SEED or RESP files can be used for instrument correction using the .simulate() method of Stream/Trace in a similar fashion