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Preparatory Commission for the Comprehensive Nuclear Test Ban Treaty Organization (CTBTO)

THE PREPARATORY COMMISSION for the CTBTO

The Preparatory Commission (Prepcom) for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) was created by a Resolution of the States Signatories of the CTBT on November 19, 1996. The Prepcom meets twice a year in Vienna, and is responsible, inter alia, for overseeing the establishment of an International Monitoring System (IMS).
The Prepcom comprises a plenary body of all States Signatories, which has established a Provisional Technical Secretariat (PTS) to install and operate the monitoring facilities of the IMS and the related International Data Center (IDC) in Vienna.  The Prepcom has two subsidiary bodies: Working Group A which addresses administrative and budgetary matters, and Working Group B which deals with issues involved in establishing the International Monitoring System and the IDC.
The PTS started work on March 17, 1997, and currently consists of about 280 staff members. It works with States Signatories to build up the International Monitoring System, the International Data Center, and a Global Communications Infrastructure.

THE INTERNATIONAL MONITORING SYSTEM

The IMS comprises 321 monitoring stations located at 260 stations in over 80 countries worldwide. It utilizes four technologies: seismic (underground seismic waves), radionuclide (radioactive isotopes), hydroacoustic (underwater seismic waves), and infrasound (atmospheric sound waves). The data from these stations flow continuously via a global communications network into the IDC in Vienna where analysts receive, analyze, and archive the data. Data from the IDC also is provided electronically to States Signatories.
The United States does not support the Comprehensive Test Ban Treaty and will not become a Party to it, but does support the work of the Preparatory Commission for the CTBTO and its Provisional Technical Secretariat with respect to the International Monitoring System (IMS). The United States is host for 37 of the IMS stations, and is also assisting with upgrading and maintaining others. 

U.S. REPRESENTATION TO THE PREPCOM

The U.S. Ambassador at the United States Mission to International Organizations in Vienna (UNVIE) is the United States Representative to the Prepcom. The Deputy Chief of Mission serves as Deputy U.S. Representative to the Prepcom. There is one Alternate Representative to the Prepcom, based in Vienna at the UNVIE Mission. Mission Officers represent the United States on a daily basis to the Prepcom, work to ensure that the global verification system is accomplished in a manner that meets U.S. concerns, and promote U.S. interests in the PTS.