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| Titel |
A Fusion Model of Seismic and Hydro-Acoustic Propagation for Treaty Monitoring |
| VerfasserIn |
Nimar Arora, Mark Prior |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250099942
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| Publikation (Nr.) |
 EGU/EGU2014-15796.pdf |
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| Zusammenfassung |
| We present an extension to NET-VISA (Network Processing Vertically Integrated
Seismic Analysis), which is a probabilistic generative model of the propagation
of seismic waves and their detection on a global scale, to incorporate
hydro-acoustic data from the IMS (International Monitoring System) network. The
new model includes the coupling of seismic waves into the ocean's SOFAR
channel, as well as the propagation of hydro-acoustic waves from underwater
explosions.
The generative model is described in terms of multiple possible hypotheses --
seismic-to-hydro-acoustic, under-water explosion, other noise sources such as
whales singing or icebergs breaking up -- that could lead to signal
detections. We decompose each hypothesis into conditional probability
distributions that are carefully analyzed and calibrated. These distributions
include ones for detection probabilities, blockage in the SOFAR channel
(including diffraction, refraction, and reflection around obstacles), energy
attenuation, and other features of the resulting waveforms.
We present a study of the various features that are extracted from the
hydro-acoustic waveforms, and their correlations with each other as well the
source of the energy.
Additionally, an inference algorithm is presented that concurrently infers the
seismic and under-water events, and associates all arrivals (aka triggers),
both from seismic and hydro-acoustic stations, to the appropriate event, and
labels the path taken by the wave.
Finally, our results demonstrate that this fusion of seismic and hydro-acoustic
data leads to very good performance. A majority of the under-water events that
IDC (International Data Center) analysts built in 2010 are correctly located,
and the arrivals that correspond to seismic-to-hydroacoustic coupling, the T
phases, are mostly correctly identified. There is no loss in the accuracy of
seismic events, in fact, there is a slight overall improvement. |
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