Automatic processing

Automatic ground motion processing is provided by AUTOSIGMA. AUTOSIGMA may be enabled to be started automatically as soon as SeisComP is started or started manually:

$ seiscomp enable autosigma
$ seiscomp start autosigma

For commandline operation triggered by an operator execute

$ seiscomp exec autosigma

Commandline help is available

$ seiscomp exec autosigma -h

Automatic event processing trigger and updates

Typically, AUTOSIGMA is executed in online mode and all information are received from the SeisComP3 messaging system. Initial automatic processing is triggered automatically by the reception of new events fulfilling the criteria of at least one of the profiles defined in profiles. An optional profile-dependent magnitude threshold may be defined by profile.name.minimumMagnitude. AUTOSIGMA is testing for new events every cron.wakeupInterval seconds. AUTOSIGMA starts processing as soon as the event parameters are received.

The data processing may be delayed with respect to the origin time of the event by cron.delayTimes seconds in order to allow for complete data within the requested time windows. The data may be incomplete due to data delays and because AUTOSIGMA requests dynamic time windows increasing with epicentral distance.

As requested time windows increase with epicentral distance a list of delay times may be provided through cron.delayTimes. In this way data acquisition is restarted after the given time. If configured reasonably the data of more-distant stations will be complete.

The event parameters are kept in memory for a duration of cron.eventKeep seconds. Re-processing is triggered by event updates and exceedence in changes in magnitude or hypocentral distance. The thresholds are given by profile.name.deltaMagnitude and profile.name.deltaLocation. Event updates are considered every cron.updateDelay seconds.

Manual event processing trigger

In offline mode, AUTOSIGMA is executed manual without the messaging system. Provide the event ID for processing a particular event contained in the SeisComP3 database

seiscomp exec autosigma --offline -E <eventID> -d mysql://<host>/<database>

Data request

Waveform data are requested using the recordStream interface for stations at epicentral distances smaller than acquisition.maximumEpicentralDistance. The static maximum epicentral distance defined in acquisition.maximumEpicentralDistance are overwritten if the magnitude-dependent maximum epicentral distances are defined in acquisition.magnitudeDistanceTable. The parameters acquisition.initialTimeout and acquisition.runningTimeout control the timeout to wait for first and subsequent records during the requests.

Data processing

The data are processed using the described algorithms.

Data products and processing output

The incidents generated by AUTOSIGMA are stored in the SIGMA database defined in output.database. Image and log files are saved in output.exportPath and output.logfile, respectively.

The output files from AUTOSIGMA include:

  • Incidents written to the database, e.g. incident.xml. The incidents contain the following information:

    • event information:
      • hypocentre: latitude, longitude, depth, date and time
      • magnitude
      • creation info: agency, author, date and time
    • per processed data stream:
      • creation information
      • unit
      • network, station, location, stream
      • epicentral distance
      • filter parameters
      • calculated parameters
        • CAV- Cumulated Absolute Velocity
        • CI - Characteristic Intensity
        • EDA - Effective Design Acceleration
        • Ia - Arias intensity
        • Ia05 - 5% of Arias intensity
        • Ia95 - 95% of Arias intensity
        • PGA - Peak Ground Acceleration
        • PGV - Peak Ground Velocity
        • PGD - Peak Ground Displacement
        • T - duration
        • Tm - mean period
        • Tp - predominant period
        • response spectrum
  • Map files with epicenter and stations written to output.exportPath showing

    • PGA: grid-gpa.png
    • MMI: grid-mmi.png
    ../_images/grid-pga.png

    Figure 4: grid-pga.png with PGA map.

    The generation of image files is controlled by the configuration parameters

  • table files for waveforms written to output.exportPath. One file per station containing

    • acceleration: NET.STA.LOC.STR-acc.slist
    • velocity: NET.STA.LOC.STR-vel.slist
    • displacement: NET.STA.LOC.STR-disp.slist.
  • Table files for spectra written to output.exportPath. One file per station containing

    • acceleration: NET.STA.LOC.STR-acc.spec
    • velocity: NET.STA.LOC.STR-vel.spec
    • displacement: NET.STA.LOC.STR-disp.spec.
  • Log files written to output.logfile.

The output files can be copied to other directories or files and processed by the user-defined script configured in output.exportScript.

Note

AUTOSIGMA does not remove or alter the output files once they are written to output.exportPath. It only creates the new files and overwrites existing ones. Files referring to previous incidents persists if not overwritten. They should be treated by the output.exportScript in the user-defined way, e.g. deleted, moved or sent to someone by e-mail.