Overcoming navigation blues

THE Indian Space Research Organisation (ISRO) launched a navigation satellite using the Geosynchronous Satellite Launch Vehicle on Monday. The satellite, NVS-01, will be joined by four other NVS satellites to complete the constellation over the next few years. This set of second-generation satellites will augment the constellation of the first-generation navigation satellites already in orbit under the Indian Regional Navigation Satellite System (IRNSS) programme launched in 2013. The navigation and positioning service provided by these satellites is known as NavIC (Navigation with Indian Constellation). When it was launched, it was claimed that the NavIC system will rival the Global Positioning System (GPS) of NASA and other regional systems such as the BeiDou Navigation Satellite System of China, Europe’s Galileo navigation system and the Russian GLONASS. But ISRO has faced many challenges in the past decade while making NavIC an Indian GPS.

The govt is yet to make it mandatory for phones manufactured in India to feature Navigation with Indian Constellation.

Like most aerospace technologies, navigation and positioning satellites are dual-purpose tools. Their primary application is strategic. The civilian use of positioning services such as GPS in smartphones and other devices was a later development. At the height of the Cold War, the American defence establishment realised that missiles, warships, military or spy satellites needed a dependable navigation system based on standard time. This resulted in the launch of the first Navigation System with Timing and Ranging (Navstar) satellite in 1978. The 24-satellite constellation became fully operational only in 1993, covering almost the entire globe. By this time, civilian applications of the technology were also on the horizon. So, the GPS was transformed into a multi-use, space-based navigation system that provided two types of services — Standard Positioning Service (SPS) for civilian use and Precise Positioning System (PPS) for military use. Both operate on different frequencies.

India realised the importance of PPS during the 1999 Kargil war when accurate positioning data was needed. It is widely believed that India was denied access to GPS by the US Air Force, which operates the service. America has maintained that GPS was never selectively deactivated during wars or anti-terrorism operations since its commissioning in 1995. Whatever may be the case, ISRO decided in 2010 to design and develop a regional navigation system that covered not only the Indian landmass but also a vast area (about 1,500 km) surrounding it. This gave birth to IRNSS in 2013. China launching its regional system in 2000 was another consideration for the launch of an Indian system. NavIC covers the Indian Ocean, which has sea routes that connect West Asia, Africa and East Asia with Europe and the Americas. It was made inter-operable with other systems such as GPS and Galileo and can work in a hybrid mode. With seven satellites, NavIC remained a regional system. A global system such as GPS has 26 operational satellites in orbit currently.

While the Indian system became operational in 2017 with three geostationary orbits satellites and four inclined geosynchronous orbit satellites, the programme encountered many challenges. The first satellite in the series, IRNSS-1, failed to work optimally, while IRNSS-1H (eighth in the series) was lost during the launch in August 2017.

The reason for the malfunctioning of IRNSS-1 was the Rubidium atomic clock which is supposed to transmit standard time — critical for accurate positioning as well. ISRO had procured the clock from a Swiss firm, SpectraTime, for all satellites. The government stated that the same company had supplied the clocks to the Russians as well and they too faced similar issues with GLONASS satellites. ISRO had to launch a replacement satellite in 2018 after fixing the glitch in the clock system. Simultaneously, ISRO began developing its own clock. The NVS satellite is fitted with the Rubidium atomic clock designed and fabricated at the Space Applications Centre, Ahmedabad.

NavIC satellites also ran into other technical problems. A study of the service, published in 2020, reported that its performance faced “challenges for positioning accuracy” during the summer season and an intense geomagnetic storm that occurred on September 8, 2017. The satellite signals are available in two bands (L5 and S). Compared to L5, the S-band faced more challenges for positioning accuracy. The same group of Indian researchers had earlier reported that “the Wi-Fi signal transmission represents a potential source of interference for NavIC applications and causes severe degradation on NavIC satellite signals.” Many communication services coexist in the same bands owing to the limited availability of the frequency spectrum. The NVS-01 signals will be available in the L1 band, which is more suitable for civilian applications.

The application of Indian navigation satellites has been low so far for various reasons. They have been used largely in government projects such as public vehicle safety, power grid synchronisation, real-time train information systems and fishermen safety alerts. To make use of the positioning, timing and navigation signals from NavIC satellites, the ground equipment and devices need to be compatible, for which they have to be fitted with requisite chipsets. For this, equipment manufacturers need to be convinced. GPS is available in all smartphones because they all come fitted with necessary receivers. Qualcomm recently started manufacturing NavIC chipsets and some smartphone manufacturers are integrating them into their products.

The Union government is yet to make it mandatory for phones manufactured in India to feature NavIC. At the same time, ISRO will have to convince all end users of the accuracy of positional and navigation signals from its satellites. ISRO should have started working with all stakeholders and potential users from the beginning, sharing data with them and encouraging device manufacturers as well as service providers to adopt its navigation system. The experience so far shows that technological self-sufficiency in critical and strategic areas is a tough task. It is also a continuous process as the technology is constantly changing to respond to new threats such as jamming. Monday’s launch, therefore, is only a significant step forward in the long journey towards technological self-reliance.