The Indian Space Research Organisation (ISRO) establish a comprehensive network of ground stations to provide Telemetry, Tracking and Command (TTC) support to Satellite and Launch vehicle missions. These facilities are grouped under ISRO Telemetry, Tracking and Command Network (ISTRAC) which its headquarters at Bangalore, Karnataka State, INDIA.ISTRAC uses the F&T system including the Cesium frequency standard units as the primary frequency source for its station at Bangalore. It is the sole purpose of the F&T system to provide the reference frequency for controlling satellites and launch vehicles. .
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