International Pulsar Timing Array
The International Pulsar Timing Array (IPTA) is a multi-institutional, multi-telescope collaboration of pulsar timing arrays (PTAs). It comprises the European Pulsar Timing Array (EPTA), the North American Nanohertz Observatory for Gravitational Waves (NANOGrav), the Parkes Pulsar Timing Array (PPTA) in Australia, the Indian Pulsar Timing Array Project (InPTA), the Chinese Pulsar Timing Array (CPTA), the Meerkat Pulsar Timing Array (MPTA), and African Pulsar Timing (APT).
Source: Wikipedia — International Pulsar Timing Array (CC BY-SA 4.0)