NET-VISA from Cradle to Adulthood. A Machine-Learning Tool for Seismo-Acoustic Automatic Association

Ronan Le Bras,David Bowers,Alexander Sudakov,Istvan Bondár,Tammy Taylor,Fekadu Kebede Alamneh,Stuart Russell,Shaban Laban,Paulino Feitio,Pierrick Mialle,Beatriz Vera,Nimar Arora,Noriyuki Kushida,Elena Tomuta,Stuart Nippress,Marcela Villarroel

doi:10.1007/s00024-020-02508-x

Ronan Le Bras, David Bowers + Show 14 more

Open Access

https://doi.org/10.1007/s00024-020-02508-x

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Abstract

A research concept that was first presented on a poster at a Comprehensive Nuclear-Test-Ban Treaty (CTBT) conference in 2009 has resulted in a fully-fledged operational software product named NET-VISA (Network Processing Vertically Integrated Seismic Analysis), which performs the Network Processing step of the automatic processing at the International Data Centre (IDC). It has become one of the tools of the waveform analysts to review and improve the IDC standard automatic third Standard Events List (SEL3) bulletin and produce the Reviewed Events Bulletin (REB), the only global seismo-acoustic bulletin. The basic scientific concepts imbedded into NET-VISA are briefly summarized in this paper but the emphasis is on the process of adopting, developing, adapting, testing, and operationalizing the initial prototype. Extensive off-line testing has shown that one of the expected benefits of NET-VISA was the significant reduction in missed events rate compared to the current Network Processing software, Global Association (GA). NET-VISA also finds some events previously missed by manual review. Starting in July 2017, and as of January 2020, NET-VISA generates an automatic bulletin, called VSEL3, in parallel to SEL3, which is also used by analysts since January 2018. Tracing the origin of the REB events has confirmed the significant reduction in missed events when complementary VSEL3 events are reviewed in addition to the SEL3 events. If sufficient confidence is established, NET-VISA has the potential to replace GA in producing the standard automatic SEL3 bulletin.

Highlights

The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is a multilateral international treaty where the states that sign the treaty, and are referred to as State Signatories in the rest of this paper, agree to prohibit any nuclear explosions in the atmosphere, underground and in-water
It is important that the software which could eventually replace Global Association (GA) which was successful in detecting all nuclear tests at the International Data Centre (IDC) starting with the 2006 announced test from the Democratic Popular Republic of Korea (DPRK) test does at least as well with detecting events in non-seismic areas
This paper presented the results of testing and evaluating the NET-VISA software at the IDC

Summary

Introduction

The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is a multilateral international treaty where the states that sign the treaty, and are referred to as State Signatories in the rest of this paper, agree to prohibit any nuclear explosions in the atmosphere, underground and in-water. A particularity is that Article IV of the Treaty (CTBT 1996) calls for an International Monitoring System (IMS) for the purpose of verification. The protocol to the Treaty includes in its Annex I the list of stations from four different technologies that constitute the sensor instrumentation part of the IMS. The Preparatory Commission to the Comprehensive Nuclear-Test-Ban Treaty (CTBTO) was established in Vienna, Austria, in 1997 to achieve among other objectives the international verification of the Treaty, including the establishment and completion of the IMS. As of August 2019, 91.6% of the stations of the IMS network are installed

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