For the first time in the world, India's GRAPES-3 muon telescope facility measured potential of thundercloud. This muon detection facility is located in ___________.

For the first time in the world, researchers at the GRAPES-3 muon telescope facility in Ooty have measured the electrical potential, size and height of a thundercloud that passed overhead on December 1, 2014. This cloud had ten times higher potential than the previous record in a cloud with 1.3 gigavolts (GV). The study of thunderclouds is helpful in navigation of aircraft and preventing short circuits in aeroplanes. The GRAPES-3 experiment (or Gamma Ray Astronomy PeV EnergieS phase-C) located at Ooty in India started as a collaboration of the Indian Tata Institute of Fundamental Research and the Japanese Osaka City University.