337 facilities employing four different technologies will monitor the planet from the poles to the tropics for evidence of nuclear testing.
300 of these facilities are already in place.
Around 15 gigabytes of data are transmitted to the CTBTO’s International Data Centre in Vienna every day by these monitoring facilities.
The data provided by the system are the property of the CTBTO’s Member States. Under the Treaty, it is up to these Member States to draw their own conclusions about whether a detected event is indeed a nuclear explosion.
Once in force, the Treaty will permit a Member State, who suspects that a nuclear test has taken place, to request an on-site inspection (OSI). An OSI will involve searching the suspected area and seeking evidence directly on the ground.
In 2014, CTBTO carried out the largest-ever on-site inspection exercise in Jordan.