• In order to monitor compliance with the Comprehensive Nuclear-Test-Ban Treaty, a global verification regime is being established.

• This is the main task of the Preparatory Commission, which needs to ensure that the regime is operational by the time the Treaty enters into force.
  

The verification regime consists of the following elements:

Global network

• The International Monitoring System (IMS) comprises a network of 321 monitoring stations and 16 radionuclide laboratories that monitor the earth for evidence of nuclear explosions on earth. The system uses four verification methods, utilizing the most modern technology available.

Verification technologies

• Seismic, hydroacoustic and infrasound stations are employed to monitor the underground, underwater and atmosphere environments, respectively.
• Radionuclide stations can detect radioactive debris from atmospheric explosions or vented by underground or underwater nuclear explosions.

Location of stations

• The establishment of the IMS poses engineering challenges unprecedented in the history of arms control, with many stations located in remote and inaccessible parts of the globe.

Certification of IMS stations

• Once established and certified as meeting all technical requirements, monitoring stations are provisionally operated by local institutions under contracts with the PTS.

The IMS is supported by the International Data Centre, which is based at the headquarters of the Preparatory Commission for the CTBTO in Vienna.

Purpose

• The IDC supports the verification responsibilities of the States Parties by providing objective products and services necessary for effective global monitoring.

Transmission of data to the IDC

• Over 200 stations are already transmitting data to the IDC, many of them continuously.
• Global coverage is being ensured through the Global Communications Infrastructure (GCI), which receives and distributes data and reporting products relevant to Treaty verification. Data are received and distributed through a network of three satellites.
• The GCI became functional in mid-1999.
• The five GCI hubs are located in the United States of America, Italy, Germany, Australia and Japan.
• GCI terminals have so far been set up at 260 IMS stations, national data centres and development sites.
• The GCI hubs are connected via terrestrial links to the IDC in Vienna.

Processing of IMS data at the IDC

• The data, which the IDC uses to detect, locate and analyse events, are processed immediately, with the first automated products being released within two hours.
• The products comprise lists of seismoacoustic events and radionuclides that have been detected by the stations.
• Analysts subsequently review these lists in order to prepare quality-controlled bulletins.

Transmission of data to States Signatories

• The IDC has been providing IMS data and IDC products to States Signatories on a test basis since 21 February 2000.
• Secure signature accounts have been established in nearly 100 countries to allow States Signatories to access these data and products.

Scientific Methods

• IDC software is state-of-the-art, in line with technical and scientific progress.

Technical Assistance

• Extensive support is given to the users designated by the States Parties by providing a standard software package, training courses and technical assistance( Visit our training and workshops area for more information).

Computer Infrastructure

• The IDC operates the computer infrastructure necessary for the Provisional Technical Secretariat (PTS) to execute its mission effectively.