IACT

IACT (imaging atmospheric [or air] Cherenkov telescope [or technique]) is a device or method to detect very-high-energy gamma ray photons in the photon energy range of 50 GeV to 50 TeV.

As of 2017, there are four operating IACT systems: High Energy Stereoscopic System (H.E.S.S.), Major Atmospheric Gamma Imaging Cherenkov Telescopes (MAGIC), First G-APD Cherenkov Telescope (FACT), and Very Energetic Radiation Imaging Telescope Array System (VERITAS). The Major Atmospheric Cerenkov Experiment Telescope (MACE) is under construction in Hanle, Ladakh, India and is set to be the highest and second-largest IACT. The Cherenkov Telescope Array (CTA) is a multinational project to build next-generation IACTs and is scheduled to begin data collection in 2022. Provided by Wikipedia