I. Bondar1 , N. Arora2 , R. Le Bras3
1MTA Research Centre for Astronomy and Earth Sciences
2Bayesian Logic, Inc.
3CTBTO Preparatory Commission
Abstract:
The CTBTO's International Data Centre is in the final stages of implementing NET-VISA, a new algorithm to perform the automatic association and location steps in the next generation IDC software. NET-VISA applies a Bayesian approach with a forward physical model using probabilistic representations of the propagation, station capabilities, background seismicity and noise statistics to obtain the maximum a posteriori solution to the highly nonlinear problems of phase association and event location. NET-VISA has been running operationally at the IDC in parallel with SEL3 since August 1, 2017. We compared 17 months between August 1, 2017 and January 1, 2019 of NET-VISA and IDC Standard Event List (SEL3) bulletins to the USGS Preliminary Determination of Earthquakes (PDE) bulletin as well as relocations of NET-VISA and IDC SEL3 bulletins with the iLoc location algorithm using travel-time predictions from the global 3D Regional Sesimic Travel Times (RSTT) model to assess the performance of NET-VISA in terms of completeness of the automatic events and location accuracy. We demonstrate that NET-VISA achieves improvements over the IDC SEL3 on both accounts and thus provides a more complete and accurate starting bulletin for the IDC analyst review.
Start time: 26/Jun/2019, 17:45 (local time)
Duration: 15 minutes
Location: Hofburg, Forum