On the use of complex rays to analyse the sonic boom of the Carancas meteorite at I08BO station located into shadow zone

2021 ◽  
Author(s):  
Annie Zelias ◽  
Olaf Gainville ◽  
François Coulouvrat
Keyword(s):  
Ray Tracing ◽  
Three Dimensional ◽  
Sonic Boom ◽  
International Monitoring System ◽  
Shadow Zone ◽  
Arrival Times ◽  
International Monitoring ◽  
Complex Ray ◽  
Test Ban ◽  
Complex Rays

<p><span>The International Monitoring System (IMS) network of the Comprehensive nuclear-Test-Ban Treaty (CTBT) detects powerful natural and artificial infrasonic sources. One of these sources are meteorites which produce multi-arrival pressure signatures similar to explosion </span><span>onces</span><span>. Long range sonic boom modeling allows to distinguish these sources from one another. Our documented case is the Carancas meteorite </span><span>that</span><span> impacted the ground in Peru on September 15th, 2007, near </span><span>the IMS </span><span>infrasound station I08BO. Since this station is located within the shadow zone, classical ray tracing cannot be used to capture the characteristics of the recorded arrivals. </span><span>Analytic continuation into complex plane of emission parameters of the ray tracing method allows to analyse the propagation in shadow zone for full</span><span>y</span><span> three dimensional problems. Contribution of complex ray ordinary differential equations integration and optimisation algorithm allows to compute complex eigenrays. Simulated infrasound wave arrival times, azimuth</span><span>s</span><span> and apparent velocities at the station are compared with Carancas records.</span></p>

Infrasound station IS25 of the International Monitoring System of the Comprehensive Test Ban Treaty : from design to certification

2021 ◽  
Author(s):  
thomas philippe ◽  
sylvain carre
Keyword(s):  
Monitoring System ◽  
International Monitoring System ◽  
Comprehensive Test Ban Treaty ◽  
Monitoring Tools ◽  
International Monitoring ◽  
Deep Forest ◽  
International Data ◽  
Comprehensive Test ◽  
Test Ban ◽  
Test Ban Treaty

<p>CEA is operating the French segment of the International Monitoring System of the Comprehensive Test Ban Treaty (CTBT). Construction of IMS stations was started on the late 90’ and one last station was pending before completing commitment of France.</p><p>Taking into account experience learned over the years, design was thought to combine enhanced detection capability and robustness. It gives also the opportunity to improve out monitoring tools and technics.</p><p>Station run 9 sensors spread out on a deep forest in Guadeloupe; power is distributed with buried cable while data are received with optical fibre to a central facility from which frames are sent to the International Data Center to the CTBTO. Constructiion was carried out in 2019.</p><p>IS25 was certified by the PTS of the CTBTO in November 2020</p>

Teleseismic slowness-azimuth station corrections for the International Monitoring System Seismic Network

1999 ◽  
Vol 89 (4) ◽  
pp. 989-1003 ◽  
Author(s):  
István Bondár ◽  
Robert G. North ◽  
Gregory Beall
Keyword(s):  
Monitoring System ◽  
Global Network ◽  
Systematic Bias ◽  
International Monitoring System ◽  
Time Data ◽  
International Monitoring ◽  
Event Location ◽  
Systematic Biases ◽  
Predicted Values ◽  
Test Ban

Abstract The prototype International Data Center (PIDC) in Arlington, Virginia, has been developing and testing software and procedures for use in the verification of the Comprehensive Test Ban Treaty. After three years of operation with a global network of array and three-component stations, it has been possible to characterize various systematic biases of those stations that are designated in the Treaty as part of the International Monitoring System (IMS). These biases include deviations of azimuth and slowness measurements from predicted values, caused largely by lateral heterogeneity. For events recorded by few stations, azimuth and slowness are used in addition to arrival-time data for location by the PIDC. Corrections to teleseismic azimuth and slowness observations have been empirically determined for most IMS stations providing data to the PIDC. Application of these corrections is shown to improve signal association and event location. At some stations an overall systematic bias can be ascribed to local crustal structure or to unreported instrumental problems. The corrections have been applied in routine operation of the PIDC since February 1998.

scholarly journals Infrasound from the 2009 and 2017 DPRK rocket launches

2018 ◽  
Vol 213 (3) ◽  
pp. 1785-1791 ◽  
Author(s):  
L G Evers ◽  
J D Assink ◽  
P SM Smets
Keyword(s):  
Source Identification ◽  
Acoustic Waves ◽  
Low Frequency ◽  
Nuclear Test ◽  
International Monitoring System ◽  
Passive Monitoring ◽  
Monitoring Technique ◽  
International Monitoring ◽  
Test Ban ◽  
Propagation Modelling

SummarySupersonic rockets generate low-frequency acoustic waves, that is, infrasound, during the launch and re-entry. Infrasound is routinely observed at infrasound arrays from the International Monitoring System, in place for the verification of the Comprehensive Nuclear-Test-Ban Treaty. Association and source identification are key elements of the verification system. The moving nature of a rocket is a defining criterion in order to distinguish it from an isolated explosion. Here, it is shown how infrasound recordings can be associated, which leads to identification of the rocket. Propagation modelling is included to further constrain the source identification. Four rocket launches by the Democratic People's Republic of Korea in 2009 and 2017 are analysed in which multiple arrays detected the infrasound. Source identification in this region is important for verification purposes. It is concluded that with a passive monitoring technique such as infrasound, characteristics can be remotely obtained on sources of interest, that is, infrasonic intelligence, over 4500+ km.

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