Expert Meetings on Special Studies (SPS) and Expert Technical Analysis (ETA) ‎ with Waveform Methods and with Radionuclide (RN) and Atmospheric Transport Modelling ‎‎(ATM) Methods‎

LOCATION
Vienna, Austria

DATES
20-24 October 2025

LANGUAGE
The working language will be English.

SYNOPSIS
The Treaty Protocol specifies that the IDC is required to respond to requests from States Signatories for what are referred to as Requested Services, which include the Special Analysis activities of ETA and SPS.

After several meetings to gather feedback on the expectations from the States Signatories, the purpose of this expert meeting is to present a draft Minimum Viable Concept (MVC) for Special Analysis as a whole and gather expert feedback on its usability, usefulness, and feasibility.

These requests for Special Analysis comprise two distinct services: Special Studies and Expert Technical Analysis:

Special Studies (SPS) provide in-depth technical reviews by experts of data from the CTBT’s International Monitoring System (IMS) to improve the estimated values for standard parameters, resulting in an Updated Radionuclide Report (URR) or an Updated Event Bulletin (UEB).

Expert Technical Analysis (ETA) uses IMS data and other relevant data provided by the requesting State Signatory to assist in identifying the source of specific events. The output of an ETA is the State Requested Methods Report (SRMR).
The Expert Meetings on SPS and ETA for Waveform Methods, and for RN and ATM Methods, will be held concurrently. There will be several joint sessions to stress-test the concept for understanding, feasibility, and practical use.
This year, we will focus on defining our MVC, building on discussions about procedures and templates from previous years.

Our MVC encompasses

• Clear definitions and distinctions between SPS and ETA.
• A structured process for requesting Special Analysis, including prioritization criteria.
• An approach to develop an agreed-upon method list for both SPS and ETA, including procedures to add and maintain methods.
• Standard Operating Procedures (SOPs) for executing SPS and ETA, including associated templates and documents.
• Potential report content for URR, UEB, and SRMR.

MEETING OBJECTIVES

1. To present the MVC concept to participants, explaining its structure, components, and intended processes.
2. Advance the common understanding of the defined procedures, building on what was developed at previous meetings.
3. Facilitate interactive sessions to stress-test the MVC and receive viable feedback on proposed procedures.
4. Gather expert feedback on:
   - The understanding of the concept among participants.
   - The usefulness and practicality of the MVC in real-world scenarios.
   - The feasibility of implementing the proposed procedures, methods and materials.
5. Identify areas for improvement and potential challenges in implementing the MVC.
6. Discuss advances and introduce new approaches to scientific methods (for the respective technologies) which could be used during Special Analysis.

Additional specific objectives for the respective technology sessions

Waveform (SHI) Methods

• Discuss methods for providing additional information about event source mechanisms, e.g. moment-tensor analysis.
• Discuss the potential contributions and limitations of waveform-correlation processing for event analysis.

Radionuclides (RN) and Atmospheric Transport Model (ATM) Methods

• Discuss methods to determine which samples are related to the same event (Screening).
• Discuss ATM methods to locate the source region for single or multiple samples.
• Characterize the atmospheric isotope background based on known man-made sources.

Data Fusion (DF)

• Discuss methods for matching SHI events to radionuclide samples.
• Discuss methods to prioritize matches based on measured properties of the SHI event and radionuclide samples.

Expected/Envisioned Outcomes

1. A refined MVC for Special Analysis, incorporating expert feedback.
2. Clear action points and recommendations for further development and implementation.
3. Enhanced understanding and endorsement among experts regarding the proposed approach.

AGENDA
The focus is on receiving feedback about the developed MVC for Special Analysis, as laid out in the 'Objectives' section of this announcement. 

PARTICIPANTS PROFILE
Experts from National Data Centres (NDCs) and research establishments involved in testing, applying, and developing waveform, radionuclide, or ATM methods that may be suitable for inclusion into the IDC automatic processing pipelines or may be applicable to Special Studies and Expert Technical Analysis.

Meeting participants are welcome to contribute to the Technical Meetings by either:

1. Preparing a contribution by presenting and discussing a method that can be used to:
   a.    Update our estimated values for standard parameters, 
   b.    Include additional data that a State Signatory can provide, or,
   c.    Asist in identifying the source of an event. 

   or 

2. Submitting a conceptual contribution outlining what the State Signatory of the participant expects from Special Analysis and how this will most likely be made use of. 
    

APPLICATION PROCEDURES
Applicants are kindly requested to visit the website ctnw.ctbto.org and complete the online application no later than 11 July 2025. This deadline also applies to the submission of abstracts for those wishing to make a presentation.

Financial support may be available for a limited number of participants. Requests for such assistance must be submitted at the time of registration by selecting the appropriate option in the online form, and no later than 11 July 2025. Applicants seeking financial support are required to submit an abstract related to one of the contribution types specified in the Objectives section.

States Signatories intending to nominate experts are requested to notify the Provisional Technical Secretariat (PTS) via the PTS Point of Contact, through their respective Permanent Missions

 

FINANCIAL INFORMATION
Applicable to PTS-funded participants only

For participants receiving funding from the PTS, please note that following the Staff Regulations and Rules and Administrative Directives, the PTS will provide the following:

• A Daily Subsistence Allowance (DSA) that is sufficient to cover related expenses during the meetings;
• The PTS travel agent will reserve, issue, and send the flight tickets to the participants for the most direct and economical route;
• Funded participants are not allowed to purchase their tickets unless, under exceptional circumstances, they are authorized to do so and only if this proves to be most cost-efficient for the PTS;
• Information on hotel booking and method of covering expenses will be sent to participants after the registration/application deadline;
• Health insurance will be provided for the duration of the meetings, including transportation time.

Requirement: Scanned passport copies.

OTHER PERTINENT INFORMATION

Visas
Participants should apply for visas, if needed, at the corresponding Embassy/Consulate upon receipt of an Acceptance Note Verbale from the PTS, in order to ensure timely processing.

Health/Accident Insurance 
It is strongly recommended that prior to departure all participants not funded by the PTS should acquire health and accident insurance for the duration of the meetings.