5.2.9.1.2. eqcorrscan.utils.picker.stalta_pick

eqcorrscan.utils.picker.stalta_pick(stream, stalen, ltalen, trig_on, trig_off, freqmin=False, freqmax=False, show=False)[source]

Basic sta/lta picker, suggest using alternative in obspy.

Simple sta/lta (short-term average/long-term average) picker, using obspy’s obspy.signal.trigger.classic_sta_lta() routine to generate the characteristic function.

Currently very basic quick wrapper, there are many other (better) options in obspy in the obspy.signal.trigger module.

Parameters:

  • stream (obspy.core.stream.Stream) – The stream to pick on, can be any number of channels.

  • stalen (float) – Length of the short-term average window in seconds.

  • ltalen (float) – Length of the long-term average window in seconds.

  • trig_on (float) – sta/lta ratio to trigger a detection/pick

  • trig_off (float) – sta/lta ratio to turn the trigger off - no further picks will be made between exceeding trig_on until trig_off is reached.

  • freqmin (float) – Low-cut frequency in Hz for bandpass filter

  • freqmax (float) – High-cut frequency in Hz for bandpass filter

  • show (bool) – Show picks on waveform.

Returns:

obspy.core.event.event.Event

Example

>>> from obspy import read
>>> from eqcorrscan.utils.picker import stalta_pick
>>> st = read()
>>> event = stalta_pick(st, stalen=0.2, ltalen=4, trig_on=10,
...             trig_off=1, freqmin=3.0, freqmax=20.0)
>>> print(event.creation_info.author)
EQcorrscan

Warning

This function is not designed for accurate picking, rather it can give a first idea of whether picks may be possible. Proceed with caution.