Expert Technical Analysis. CTBT definitions Project: Further development, commissioning, maintenance and support of the SHI Expert Technical Analysis Suite Spot Check Tool based on cross correlation: concept Automatic cross correlation processing, XSEL Automatic Spot Check: XSEL, SEL*, REB, (VSEL) Interactive Spot Check Tool: for REB and SEL3 Spot Check Tool: control panels Spot Check Tool: code flexibility ParMT: Preliminary results and project tasks

1. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
P3.5-355
SHI Expert Technical Analysis
Spot Check Tool and ParMT
Ivan Kitov ( Ivan.Kitov@ctbto.org )
Ilya Dricker ( Ilya.Dricker@isti.com )
Oleksandr Sukhotskyi ( OleksandrSukhotskyi@isti.com )

2. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
Spot check of seismic and infrasound data and products at the IDC using
waveform cross correlation and the REB historical events
Ivan Kitov and Christos Saragiotis
• Expert Technical Analysis. CTBT definitions
• Project: Further development, commissioning, maintenance and
support of the SHI Expert Technical Analysis Suite
• Spot Check Tool based on cross correlation: concept
• Automatic cross correlation processing, XSEL
• Automatic Spot Check: XSEL, SEL*, REB, (VSEL)
• Interactive Spot Check Tool: for REB and SEL3
• Spot Check Tool: control panels
• Spot Check Tool: code flexibility
• ParMT: Preliminary results and project tasks
• Discussion
Outline

3. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
One of the IDC services to the States Parties is Expert Technical
Analysis (ETA). In particular, Paragraph 19 of the Protocol to the
CTBT (Part I), says, that
”The IDC shall carry out, at no cost to States Parties, special
studies to provide in-depth, technical review by expert analysis of
data from the IMS, if requested by the Organization or by a State
Party, to improve the estimated values for the standard signal and
event parameters”.
Spot check of seismic and infrasound data and products at the IDC using
waveform cross correlation and the REB historical events
Ivan Kitov and Christos Saragiotis
SHI Expert Technical Analysis

4. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
Paragraph 20, provides that the methods for supporting data access
and the provision of data shall include the following service:
Assisting individual States Parties, at their request and at no cost
for reasonable efforts, with expert technical analysis of IMS data
and other relevant data provided by the requesting State Party, in
order to help the State Party concerned to identify the source of
specific events. The output of any such technical analysis shall be
considered a product of the requesting State Party, but shall be
available to all States Parties.
Spot check of seismic and infrasound data and products at the IDC using
waveform cross correlation and the REB historical events
Ivan Kitov and Christos Saragiotis
SHI Expert Technical Analysis

5. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
According to Annex 2 to the Protocol, one of the defining
parameters estimated by the IDC is the hypocentre solution based on
SHI data, which includes the origin epicentre coordinates and depth.
Besides, one of the characterization parameters for International
Data Centre Standard Event Screening mentioned in the same
Annex is focal mechanism. In routine IDC processing, source
location is calculated with the globally robust and steady technique
providing quasi-uniform location accuracy and uncertainty which
depends on the quality of relevant detections. For ETA, advanced
and state-of-the-art techniques should be used to enhance automatic
and interactive location.
Spot check of seismic and infrasound data and products at the IDC using
waveform cross correlation and the REB historical events
Ivan Kitov and Christos Saragiotis
SHI Expert Technical Analysis

6. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
ANNEX 2 TO THE PROTOCOL
List of Characterisation Parameters for International Data Centre Standard Event Screening
1. The International Data Centre standard event screening criteria shall be based on the standard event
characterisation parameters determined during the combined processing of data from all the monitoring
technologies in the International Monitoring System. Standard event screening shall make use of both
global and supplementary screening criteria to take account of regional variations where applicable
2. For events detected by the International Monitoring System seismic component, the following
parameters, inter alia, may be used:
location of the event; (Spot Check Tool)
depth of the event; (ParMT)
focal mechanism; (ParMT)
comparative measures to other events and groups of events; (Spot Check Tool)
SHI Expert Technical Analysis

7. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
Spot check of seismic and infrasound data and products at the IDC using
waveform cross correlation and the REB historical events
Ivan Kitov and Christos Saragiotis
Project: Further development, commissioning, maintenance
and support of the SHI Expert Technical Analysis Suite
The ETA Suite Prototype consists of two major components:
SCT and ParMT
The SCT (Spot Check Tool) is an ETA tool (e.g., a tool for review officers) for
checking the completeness of the REB, and for testing certain hypocenter solution
hypothesis in interactive and automatic mode.
ParMT (Parametrical Moment Tensor Estimator) is an ETA tool for the shallow
events depth and magnitude determination based on the moment tensor estimation.
The ParMT software prototype was finalized as an alpha release by the end of
2019.

8. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
Spot check of seismic and infrasound data and products at the IDC using
waveform cross correlation and the REB historical events
Ivan Kitov and Christos Saragiotis
Spot Check (waveform cross correlation)
is waveform cross correlation processing with
appropriate number of real and/or synthetic
master events focused on specific area, time
interval or set of events
Spot Check Tool: approach

9. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
Spot check of seismic and infrasound data and products at the IDC using
waveform cross correlation and the REB historical events
Ivan Kitov and Christos Saragiotis
12 from 84 REB events (14%) for April 26, 2020 have negative NET-VISA Score, i.e. contradict the NET-
VISA probabilistic model based on the REB events. Possible reason – poor phase association/mislocation
URGENT NEED OF THE SPOT CHECK TOOL: NET-VISA FINDINGS
Spot Check Tool: the REB quality and reliability

10. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
Spot check of seismic and infrasound data and products at the IDC using
waveform cross correlation and the REB historical events
Ivan Kitov and Christos Saragiotis
• Spot Check Tool development: to facilitate a work of the Independent Reviewer (IR)
• Underlying methodology: waveform cross correlation
• Processing stages: master selection, detection using the matched filter, Local
Association (LA), Conflict Resolution (CR), Spot Check
• Spot Check Modes: Interactive and Automatic
 Interactive: under flexible scenario developed by the IR
 Automatic: on daily basis, building XSEL (cross correlation standard event list)
bulletins and conducting automatic comparison with SELs (same day analysis)
and REB (upon its completion) bulletins.
Spot Check Tool: Modes

11. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
Spot check of seismic and infrasound data and products at the IDC using
waveform cross correlation and the REB historical events
Ivan Kitov and Christos Saragiotis
• Aimed at improvement of the Reviewed Event Bulletin (REB) quality
• Final level of the interactive review hierarchy (independent review)
• Provides an extended check of bulletin and analysis quality
• Identifying both consistencies and inconsistencies in the REB
• Reviewed areas usually include event location anomalies, seriously mislocated
events, missing large events, and unqualified or ‘bogus’ events representing
incorrect / invalid data associations or incorrect detections, or REB events not
meeting event definition criteria.
• One more implementation of the master-event approach
Spot Check Tool

12. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
Routine XSEL automatic processing: stages
Spot Check Tool: XSEL

13. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
P3.5-355
Spot check of seismic and infrasound data and products at the IDC using
waveform cross correlation and the REB historical events
Ivan Kitov and Christos Saragiotis
Routine XSEL processing. Spot: whole globe, all seismic
and infrasound data for a day
Spot Check Tool: XSEL automatic processing

14. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
Spot check of seismic and infrasound data and products at the IDC using
waveform cross correlation and the REB historical events
Ivan Kitov and Christos Saragiotis
- Selected 13,000 master (historical REB) events distributed over the globe and depth
- Approximately 5000 events are selected by the best cross correlation with neighbours and have
higher priority
- Daily WCC processing in 50 Flinn-Engdahl seismic regions
- Only the best stations are used in basic XSEL processing
- The choice of filters, correlation windows, channels of arrays stations is suboptimal
- Adaptive detection thresholds (for given setting) for each master/station pair
- Local Association within each seismic region
- Conflict Resolution between all created event hypotheses
- Creation of basic automatic XSEL – a SEL3 analogue
Additional stage is needed
Spot Check of the automatic XSEL to improve or reject XSEL event hypotheses
using an extended number of master events
RoutineXSELprocessinglimitedinthenumberofmasters,andthus,coverage/resolution
Spot Check Tool: XSEL - from routine to Spot Check

15. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
Spot check of seismic and infrasound data and products at the IDC using
waveform cross correlation and the REB historical events
Ivan Kitov and Christos Saragiotis
Automatic XSEL Spot Check processing
Spot Check Tool: Automatic Spot Check of the XSEL

16. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
P3.5-355
Spot check of seismic and infrasound data and products at the IDC using
waveform cross correlation and the REB historical events
Ivan Kitov and Christos Saragiotis
AUTOMATIC
SPOT
CHECK:
SEL3
Spot Check Tool: Automatic Spot Check of SEL3

17. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
Spot check of seismic and infrasound data and products at the IDC using
waveform cross correlation and the REB historical events
Ivan Kitov and Christos Saragiotis
AUTOMATIC
SPOT
CHECK:
REB
Spot Check Tool: Automatic Spot Check of the REB

18. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
Spot check of seismic and infrasound data and products at the IDC using
waveform cross correlation and the REB historical events
Ivan Kitov and Christos Saragiotis
For all studied REB events, a set of
best master (historical REB) events
within 3 (predefined range) degrees
is selected and the time intervals
±10 min around the measured and
theoretical arrival times are
processed by standard XSEL
procedure. The number of master
events depends on the semi-major
axis (location quality) of a given
REB event. The whole depth range
for historical REB events is
covered. 80 from 84 events were
confirmed by Automatic Spot
Check, i.e. (REB-ready) XSEL
events matching REB events by two
phases (stations) were built.
AutomaticSpotCheck:REBandmastereventselection
Spot Check Tool

19. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
Spot Check Tool Architecture
• Information backbone: historical IDC database, allows for testing current event
hypotheses with the archived event bulletins using master event approach
• SCT frontend: Liferay IDC portal; allows access to the tool to the IR, lead analysts and
broader (authorized) CTBT expert community
• SCT computational backend: distributed, including servers and workstations. To migrate
to the GPU-server in future
Spot Check Tool: Interactive

20. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
P3.5-355
SCT Web GUI MAIN SCREEN as a SWP Liferay Portlet

21. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
P3.5-355
SCT Web GUI MAIN SCREEN with a Use Case menu opened
Use Case
menu

22. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
P3.5-355
SCT Web GUI ORID List selection SCREEN

23. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
P3.5-355
SCT Web GUI ORID List selection by AREA

24. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
P3.5-355
SCT Web GUI ORID List selection by DATE

25. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
P3.5-355
SCT Web GUI Filter selector from detection list

26. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
P3.5-355
SCT Web GUI Cross-Correlation Configuration page

27. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
P3.5-355
SCT Web GUI Log page during execution

28. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
P3.5-355
SCT Web GUI Results page

29. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
Spot Check Tool:
Code flexibility

30. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
Constant
Advanced
Spot Check Tool:
Code flexibility

31. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
Spot Check Tool: Code flexibility

32. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
Spot Check Tool: Code flexibility

33. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
ParMT Tasks
• Thoroughly tune and calibrate the software with the data from the IDC database and
historical data from other sources (including IRIS, DTRA, LLNL, etc.), taking into account
data and metadata - related issues (instrument response, geographical coverage, insufficient
metadata, etc.)
• Develop an interface or a plugin allowing parsing of the ParMT-based body and surface
wave synthetic seismograms (regional and teleseismic) to Spot Check Tool, thus providing
substantial SCT code reuse
• Create training materials for the ParMT training sessions at NDC workshops, etc. Assist
Capacity Building and Training Section (CBT) of the IDC in creating distribution software
bundles to be used at the NDCs. Conduct ParMT training session, in particular with CBT.
• The software must be integrated with the NDC-in-a-Box software as a special release for the
ETA. The level of integration will be discussed in the beginning of the extension of the Work.

34. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
ParMT Tasks (cont.)
•To use regional velocity models (e.g., CRUST1) in order to improve waveform prediction for
very shallow events like underground nuclear tests.
•To introduce various underground nuclear explosion (UNE) models with depth-dependent
source function (e.g., Mueller-Murphy) to predict waveforms from low-yield UNEs in the
estimation of focal mechanism (moment tensor) and depth of burial. To use well-constrained
empirical source functions for UNEs in different rock types.
• To use methods of dimensionality reduction (e.g., PCA, ICA) to construct semi-empirical
synthetic source functions for moment tensor calculation and depth estimate
• To estimate potential improvement in screening power of focal mechanism with the use of
the UNE models based on historical and IMS data.

35. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
ETA Suite Prototype for SHI data: Depth determination based on moment tensor estimation
8
ParMT

36. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
New applications at the IDC for SHI Expert Technical Analysis
Ivan Kitov; Mikhail Rozhkov; Yuri Starovoyt; Ronan Le Bras
Is.1-353
Turkey 2017-11-24 21:49:15 UTC
37.085°N 28.622°E 5.2 km depth
Canada 2017-12-22 08:00:13 UTC
65.481°N 134.083°W 3.5 km depth
9
ParMT

37. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
Depth=
0.4
km
Depth=
1.6
km
10
ParMT

38. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
38
SHAKTI
explosion
(India
1998-05-11:10:13:42.000
)
Chagai-I
explosion
(Pakistan
1998-05-28:10:16:15.000) 11
ParMT

39. CTBTO.ORG
Disclaimer: The views expressed on this poster are those of the author and do not necessarily reflect the view of the CTBTO
Poster No.:
PUTTING AN END TO NUCLEAR EXPLOSIONS
• The Frontend GUI of the Spot Check Tool is ready for testing
• The Frontend GUI is flexible and can be easily modified to include new parameters
• Daily automatic Spot Check of the XSEL, REB, and SEL3 is used to collect data and results
for further usage in the Interactive Spot Check Tool as default setting.
• Adaptive mechanisms widely used in the SCT allow for continuous incorporation of new
information (e.g., machine learning based on valid/invalid event classification by analysts)
into interactive and automatic processing also with daily increasing number of master events
• The ParMT GUIs are tested using various source types and settings of the defining parameter
• Further development of the ParMT and SCT according to the Project
SHI Expert Technical Analysis: Discussion