Introduction

Catalyst is a graphical tool for the evaluation and refinement of event-parametric catalogues in SeisComP. It works on picks and origins, not on waveforms: it loads the picks and origins of a time window from the database or from an XML file, finds the events hidden in them, locates and checks those events, and sends the results back to SeisComP.

Typical questions Catalyst answers are:

  • Which events are hidden in a large set of automatic picks that the real-time system did not associate?

  • Which origins in a catalogue are duplicates, mislocations or false associations?

  • How does the catalogue change when it is relocated with a different locator, velocity model or association tolerance?

  • Which origins pass a set of quality rules, and which need an analyst?

Concept

Catalyst treats the catalogue as a working set that is refined in steps:

  1. Load picks and, optionally, origins for a time window.

  2. Cluster the picks: remove duplicate picks (aggregation) and form candidate events from the unassociated picks (nucleation).

  3. Refine the origins: associate picks, relocate, merge duplicates and recover further events from swarms (refine). Smart-locate does this automatically by following the decision rules of an experienced analyst.

  4. Check the origins with quality-control rules and decide which to keep, confirm or reject.

  5. Send the updated origins to the messaging system, or save them to a file.

Every step can be run on the whole working set or on a selection. Results are shown as tables, on the map, in the 3D view and in diagnostic plots of the active origin, so each decision can be checked visually.

All processing settings can be stored in processing profiles, for example one profile per network or region.

Applications

Applications of catalyst are:

  • Reprocessing of automatic picks to find events missed in real time, for example during swarms and aftershock sequences,

  • Cleaning catalogues of duplicate, split and mislocated events,

  • Detection and location of infrasound sources from array picks,

  • Comparison of locators, velocity models and processing settings on the same data set,

  • Preparation of reviewed catalogues for publication.