In the very early hours of February 26, 2019, the cold, crisp air of a fading winter gave way to a heated phase of India-Pakistan tensions as a formation of Indian Air Force (IAF) Mirage-2000s hit terror targets inside Pakistan. This air attack in response to the Pulwama terror attack, which claimed the lives of 40 CRPF personnel, was carried out using GPS-guided weapons.These bombs gave the Indian aircraft enough separation from their target so as to safely extricate themselves after deploying their munitions.A little over six years ago, key terror targets in Pakistan, which included the headquarters of both Lashkar-e-Taiba, located in Muridke, and the headquarters of Jaish-e-Mohammad, in Bahawalpur, were struck with pinpoint accuracy in response to the killing of tourists in Pulwama in Kashmir. Both these strikes were carried out using weapons guided by a constellation of satellites.Satellite navigation is increasingly gaining importance for advanced militaries. Satellite navigation is not only important for guiding precision weapons on to a target, but they are also important for other tasks such as navigation, drawing up a common picture to know dispositions of units of both sides, avoiding friendly fire and increasingly to optimally utilise autonomous systems across different domains. Due to the sensitive and critical nature of this technology, different entities have developed their own satellite navigation systems.
Why militaries need their own navigation systems
The Americans, first on the bus developed the Global Positioning System, the Soviets and now the Russians use the Global Navigation Satellite System (GLONASS), China the BeiDou Navigation Satellite System and the European Union has developed the Galileo. While Japan and India have developed Regional Navigation Satellite Systems (RNSS). Tokyo has developed the Quasi-Zenith Satellite System (QZSS) and New Delhi has set in place the Indian Regional Navigation Satellite System (IRNSS), also known as NavIC (Navigation with Indian Constellation).
Satellite navigation systems developed and deployed by different countries.
The NAVIC constellation was designed to deliver an indigenous navigation and positioning services, comparable to the US GPS but specifically tailored for regional coverage. For the armed forces the constellation will ensure secure, encrypted signals critical for targeting, communications and mobility. The aim of deploying an Indian satellite constellation is to reduce reliance on foreign systems, enhance resilience against denial or spoofing in conflict scenarios. Its integration into missiles, aircraft and naval platforms will strengthen operational autonomy. NAVIC also supports civilian applications.
How satellite navigation finds a target
Global Navigation Satellite Systems work on a surprisingly elegant principle, they let a receiver, whether in your phone or a fighter jet, calculate its exact position by measuring how long radio signals take to travel from multiple satellites orbiting the Earth. Since these signals travel at the speed of light, even a tiny timing error translates into a massive positional error, a single microsecond of drift can throw off a location fix by nearly 300 metres.This is precisely where atomic clocks come in. Each satellite carries atomic clocks, typically rubidium or caesium-based, that measure time with extraordinary precision by tracking the natural oscillation frequency of atoms, a rate so stable it barely drifts by a second over millions of years. To fix a position accurately, a receiver needs signals from at least four satellites simultaneously, three to triangulate location in three-dimensional space, and a fourth to correct for the receiver’s own less-precise internal clock.Without perfectly synchronised atomic clocks across the satellite constellation, the entire system falls apart, since even nanosecond-level timing errors compound into navigation inaccuracies that could provide imprecise positioning.
From submarines to smart weapons: How GPS became a military tool
The story of GPS begins not on our smartphones but with the US Navy, which developed it in the 1960s under the Navy Navigation Satellite System to guide vessels and, crucially, to track submarines carrying nuclear missiles. The project was spearheaded by the Advanced Research Projects Agency alongside Johns Hopkins University’s Applied Physics Laboratory.Inspired by the Navy’s early work, the Department of Defense expanded the effort in 1978, launching a network of 24 satellites for a far more advanced system. President Reagan opened GPS to commercial aviation in 1983 for safer navigation, while advances in solid-state microprocessors and bandwidth utilisation through the late 1990s pushed the technology further forward. The system became fully operational for military use by 1993, before former US President Clinton opened it up for global civilian and commercial use in 2000. The battlefield impact came into sharp focus during the first Gulf War, the first major use of satellite navigation in warfare, where US Army armoured units relied on GPS to outflank Iraqi positions with striking precision.Recognising that GPS needed to keep pace with expanding applications, work on modernisation continued for decades, culminating in the upgraded satellites, the last of which launched in 2017. The following year in 2018, the first GPS III satellites went up, delivering three times the positional accuracy of their predecessors.
Kargil lesson: Why India built NavIC
The IRNSS was a result of the Kargil conflict, India was denied access to the more accurate military grade GPS data during the Kargil conflict. India had to rely on the civilian grade signals that were less accurate. The Kargil Review Committee headed by K Subrahmanyam had also highlighted the lack of satellite based surveillance. India is now planning to launch a 52-strong surveillance satellite constellation under the third phase of the Space Based Surveillance project.Navic, was designed to run as a constellation of seven satellites backed by a round-the-clock network of ground stations, with three satellites placed in geostationary orbit and four in inclined geosynchronous orbit. The system offers two distinct services, a Standard Position Service for civilian users and a more precise Restricted Service reserved for strategic applications. The constellation covers the entire country and extends roughly 1,500 kilometres beyond the borders. From transportation across land, air and sea to location-based services, personal mobility, resource monitoring, surveying, scientific research and time synchronisation, Navic has fulfilled many roles.
NavIC beyond the battlefield
For civil aviation specifically, ISRO and the Airports Authority of India jointly developed GAGAN, or GPS Aided Geo Augmented Navigation, a satellite-based augmentation system tailored for Indian airspace. Designed to work seamlessly alongside similar international systems such as America’s WAAS, Europe’s EGNOS and Japan’s MSAS, GAGAN enhances the accuracy, availability and reliability of satellite navigation across each phase of flight.
In the 21st century, the strategic continuum now extends from seabed to space, spanning multiple domains where national security is increasingly contested. Knowing where you are is not merely a matter of geography, but a matter of strategic autonomy, sovereignty, and technological sovereignty. An indigenous satellite navigation system is not a luxury, it is an unavoidable necessity, one that underwrites both our sovereignty and our national security. We need an established and dependable system. In the era of networked warfare and smart munitions, the need for satellite guidance, and the technological sovereignty it guarantees, is now more than ever. During peace this system will strengthen our economy and safeguard our sovereignty, and in conflict it will protect our freedom of action and defend our national security.
Lt General PS Minhas (retired), defence analyst
NavIC’s big problem: Only three satellites remain operational
The government has told the parliament, that the seven-satellite constellation, has now dropped to just three operational satellites, one short of the minimum four required to provide an accurate fix. The shortfall traces back to March this year, when the atomic clock aboard IRNSS-1F failed, joining a string of earlier satellite setbacks. Union Minister of State for Space Jitendra Singh told the Lok Sabha that only IRNSS-1B, IRNSS-1I and NVS-01 currently provide positioning, navigation and timing services.Of the 11 satellites ISRO has launched under the programme over the years, several have either completed their design life, suffered onboard clock failures, or failed to reach their intended orbit altogether. Notably, many of Navic’s early reliability issues stemmed from imported atomic clocks that repeatedly malfunctioned, a problem the newer NVS-series satellites, which use indigenously developed clocks, are meant to fix. ISRO now working to restore the constellation through the upcoming launch of the next-generation NVS-03 satellite.
Why the shortfall matters for India’s military
The Indian armed forces are in the middle of a massive modernisation drive, as the armed forces are increasingly moving towards networked warfare. Such a paradigm would increase the dependency on satellite based positioning in order to have all forces on the same page, having a functional indigenous satellite navigation system will be a strength in such a scenario, as the country would not be at the mercy of any other country to provide it with such a critical capability.
