Seiscomp3 Autopicker using the Baer / Kradolfer Picking Algorithm
Introduction
Bkpicker is an implementation of the Baer/Kradolfer picker adapted to Seiscomp3.
It was created by converting Manfred Baers picker_ppick.f from Fortran to C++ and inserting it as a replacement for the picker algorithm into a copy of gfzpicker.cpp from Gempa which was renamed to bkpicker.cpp.
Bkpicker is included in scautopick and can be activated in the corresponding configuration file.
Configuration
Edit ~/.seiscomp3/scautopick.cfg, add the following line:
picker=BK # can be GFZ, ARAIC or BK
You can configure some parameters for the picker algorithm and the filter:
# Signal time interval to be postprocessed by the postpicker. # Begin and End are in seconds relative to the trigger picker.BK.signalBegin=-23 picker.BK.signalEnd=60 # Filter configuration picker.BK.filterType = BP # BP (Bandpass) is currently the only option picker.BK.filterPoles = 2 # number of poles picker.BK.f1 = 5 # lower cutoff freq. in Hz picker.BK.f2 = 20 # upper cutoff freq. in Hz # Baer / Kradolfer picker algorithm parameters picker.BK.thrshl1 = 15 # threshold to trigger for pick (c.f. paper), default 10 picker.BK.thrshl2 = 20 # threshold for updating sigma (c.f. paper), default 20
Usage Example For Testing The Picker
scrttv --buffer-size 300000000 --record-file example.mseed scautopick -u dummy --db-disable -vvvvv --console=1 -I example.mseed
Scrttv will first show the waveform without picks, and then, when scautopick is running, will add the picks to the waveform as they are detected by scautopick.
If you want to change the picker only for a short test without modifying the config file, you can also select the postpick processor on the command line:
scautopick --picker=BK -u dummy --db-disable -vvvvv --console=1 -I example.mseed
Description of the Baer / Kradolfer Algorithm
For details see the Bulletin of the Seismological Societyety of America, Vol. 77, No. 4, pp. 1437-1445,August1987: "An Automatic Phase Picker For Local And Teleseismic Events" by Manfred Baer and Urs Kradolfer