Isro and CSIR sign a Mou to increase accuracy in satellite navigation

The Council for Science and Industrial Research (CSIR) and the Indian Space Research Organisation (Isro) on Friday signed a MoU for exchanging time and frequency traceability to bring accuracy in satellite navigation and other ventures. The CSIR is the custodian and mandated to maintain the Indian Standard Time (IST), and as per the memorandum of understanding (MoU), it will provide time and frequency traceability to the Isro. At the national level, time synchronisation is essential for all kinds of financial transactions, stock handling, digital archiving, time stamping, international trade, national security and to prevent cyber crimes. The MoU was signed in the presence of Union Minister for Science and Technology Harsh Vardhan and Minister of State for Department of Space Jitendra Singh at CSIR Science Centre here. “Isro needs accuracy up to nanoseconds level for navigation, surveillance and other national missions, whereas millisecond or micro second accuracy is sufficient for day-to-day activities,” said Jitendra Singh. Speaking at the event, Harsh Vardhan said the development dynamics of a country was highly dependent on the preciseness of time keeping. “Smart grids for electricity distribution networks have made it essential to use precise time synchronisation… Weather forecast depends on accurate time information and its synchronisation,” he said. Under the MoU, the National Physical Laboratory (NPL) of the CSIR will provide the Universal Coordinated Time (UTC) traceability to the Time Scale of Indian Regional Navigational Satellite System (IRNSS) - an independent navigation satellite system being developed by the Isro. The UTC has an uncertainty of 20 nanoseconds. To reduce this uncertainty to make it more precise, the Two Way Satellite Time and Frequency Transfer (TWSTFT) system between CSIR-NPL’s Lab in New Delhi and Isro’s Lab in Bengaluru and Lucknow have been set up. According to the CSIR, the accuracy of satellite navigation systems depends on the proper sync of onboard clocks. For navigation purposes, at least four satellites are needed to know someone’s position accurately, for which the time has to be incredibly accurate. “The light travels 30 centimetres in one nanosecond - 300 million metres in one second. Thus, even a tiny error in the time signal could put a defined activity by a very long way,” said a CSIR statement.