GPS Gave America An Edge — Until China Built A Triad Of Satellites, Towers And Fibre

Every time your phone shows exactly where you are, or a plane lands precisely on time, or a financial transaction clears in milliseconds, an invisible system is quietly doing its job. You don’t see it. Most people don’t even know it exists. But it’s what lets the digital and physical worlds move in sync, across continents and time zones, with astonishing accuracy.

This global infrastructure isn’t buried in cables or housed in data centres. It is enabled by a complex web of satellite constellations, ground stations, and signal processing technologies, the most well-known of which is the US’ Global Positioning System (GPS).

These signals allow systems to calculate three things with extraordinary accuracy: location, movement, and time. Together, this triad — Positioning, Navigation, and Timing, or PNT — gives everything from digital networks to transportation and communication systems a common reference for space and time.

By calculating the time it takes for signals to travel from satellites to a receiver, devices on the ground can triangulate their position, determine velocity, and synchronise their internal clocks with remarkable precision.

These functions are now so deeply embedded in daily life that most people remain unaware of how much depends on their constant, seamless operation.

This same infrastructure also underpins the modern battlefield. Militaries rely on PNT to navigate, coordinate strikes across dispersed units, and guide autonomous platforms like drones. Its signals help synchronise encrypted communications and ensure that time-sensitive operations, from targeting to resupply, occur without delay or error.

Without reliable PNT, a drone might veer off course, a ship could miscalculate its location, or missile systems may fail to engage accurately. In a high-tempo conflict, these are not minor glitches, they are the difference between operational success and failure.

But for all its sophistication, satellite-based PNT remains fragile. The signals it relies on are extremely weak by the time they reach Earth, making them susceptible to jamming, the deliberate broadcasting of interference that overwhelms and blocks legitimate signals. They are also vulnerable to spoofing, where false signals are transmitted to deceive receivers about their true location or time. These disruptions can misdirect ships, cause aircraft to stray, and throw entire digital systems out of sync.

In addition to these electronic threats, satellite infrastructure faces physical risks. Anti-satellite weapons, orbital interceptors, and directed-energy systems are all being developed to disable or destroy satellites.

The risks are no longer theoretical. China has quietly developed and repeatedly demonstrated the ability to exploit them for strategic gain.

One of the clearest examples came in 2019, during the now-infamous Shanghai Port “circle spoofing” incident. Dozens of ships reported GPS positions that showed them moving in perfect loops — often on land — a clear indicator of deliberate spoofing rather than system error. The false signals appeared designed to conceal real vessel movements, likely to obscure port operations or test electronic warfare capabilities.

Similar interference has since been detected near Hainan Island, where Chinese nuclear submarines are based, across the South China Sea, which China claims in entirety, and in the East China Sea, where Chinese and Japanese territorial claims overlap.

China’s capacity to tinker with GPS signals is expanding. Thanks to a 2017 interoperability agreement, its BeiDou system is compatible with GPS, making it easier for Beijing to imitate or manipulate those signals when needed.

What these disruptions increasingly suggest is that satellite-based PNT is no longer just a background utility. It is becoming a contested domain in its own right.

And while China has developed tools to degrade PNT systems used by others, it has simultaneously invested in strengthening its own, adding layers of redundancy to guard against the very vulnerabilities it seeks to exploit.

From ground-based backups like enhanced-Loran (Long-Range Navigation) to fibre-linked timing networks and multi-orbit satellite constellations like BeiDou, Beijing has built a multi-layered, resilient PNT architecture, designed not just to survive disruption, but to operate through it.

From 'unforgettable humiliation' to triumph

In March 1996, Taiwan was preparing for its first direct presidential election. In Beijing, it looked like a provocation in slow motion, one that couldn’t be ignored.

Just months earlier, President Lee Teng-hui had described Taiwan’s relationship with the mainland as “state-to-state” — a phrase that, to the Chinese Communist Party, sounded uncomfortably close to a declaration of independence, even if informal. The People’s Liberation Army (PLA) was ordered to respond with a show of force.

From launch sites in Fujian, the PLA fired three DF-15 short-range ballistic missiles into the East China Sea. At the time, the DF-15 was a relatively new system, a marker of China’s growing precision-strike capability. But while the first missile landed near its intended splash zone, the second and third did not behave as expected.

Midway through their flight, the two missiles veered off course. PLA commanders couldn't confirm where the warheads had landed, or why. For China, the failure was a public stumble at a moment when it could least afford one.

“It was a great shame for the PLA … an unforgettable humiliation,” a retired senior PLA colonel would recall years later. “That’s how we made up our mind to develop our own global [satellite] navigation and positioning system, no matter how huge the cost."

The crisis was brief. But the GPS disruption, or the fear of it, exposed a blind spot in China's military capabilities. It convinced Beijing that no modern power could afford to rely on a foreign-owned navigation system in wartime. And it set in motion the creation of a sovereign Chinese alternative to GPS — BeiDou.

Nearly 30 years later, BeiDou is at the core of China’s PNT infrastructure. And in many ways, it is already more resilient than the older, US-operated GPS.

The most visible edge lies in sheer numbers. As of 2025, BeiDou is supported by a constellation of 56 satellites, nearly double the number that currently provide GPS coverage. This expanded constellation increases the likelihood that receivers on the ground, whether in urban canyons or mountainous terrain, maintain uninterrupted access to satellite signals. It also builds in greater fault tolerance. Disabling a few BeiDou satellites is unlikely to meaningfully degrade the system's performance.

But quantity is only part of the story. BeiDou is also structured differently.

The Chinese system uses a mix of three satellite orbits — geostationary (GEO), inclined geosynchronous (IGSO), and medium Earth orbit (MEO) — to build a more flexible and resilient navigation system. GEO satellites stay fixed over the equator and provide constant coverage across Asia. IGSO satellites follow looping paths that pass frequently over China, helping maintain strong signals even in areas where terrain or buildings block satellite visibility. MEO satellites orbit the globe and provide worldwide coverage.

This layered design gives BeiDou an edge in both regional performance and global reach. It improves accuracy, strengthens reliability, and makes the system harder to disrupt.

In contrast, GPS satellites are confined to MEO, making the system more uniform and potentially more vulnerable to synchronised attacks or orbital congestion.

BeiDou’s ground segment is also more robust. China has built an extensive network of over 120 ground control and monitoring stations, compared to just 11 that support the GPS constellation. This wider network gives operators more visibility into system performance at any given moment. If a satellite shows irregularities in its signal, timing, or orbit, China’s broad ground network allows operators to respond quickly, correct the issue in real time, and keep the system functioning with minimal disruption.

China is also extending this resilience to its allies. In 2018, it gave Pakistan access to BeiDou’s military-grade navigation data, enabling far more precise targeting for missiles, aircraft, and naval platforms. Indian officials say Pakistan has since shifted entirely to BeiDou for both military and civilian use, effectively cutting its dependence on GPS.

China is now doubling down on its advantage in satellite-based PNT by building a new constellation in low Earth orbit (LEO), called CentiSpace. Research suggests that PNT signals from LEO are not only significantly stronger than those from traditional medium Earth orbit (MEO) satellites but also harder to jam or spoof. When combined with MEO signals, they offer far greater positional accuracy and signal resilience.

Back in 2019, a Chinese official confirmed that Beijing had submitted an application to the International Telecommunication Union to deploy 120 LEO PNT satellites at an altitude of 700 km. That plan is now in motion. In January 2025, China launched 10 CentiSpace navigation enhancement satellites, the first phase of a larger LEO constellation that is expected to grow to around 190 satellites over time.

Layers of resilience on land

Given the inherent fragility of satellite-based PNT, China has been adding layers of redundancy on the ground to ensure there is no disruption even if BeiDou is compromised. Over the last decade, it has built nearly 300 ground-based backups, fibre-optic networks to transmit accurate timing information, and an eLoran system, a ground-based alternative to satellite-based navigation.

The most critical of these is eLoran, a land-based navigation and timing system that uses low-frequency radio signals. These signals can propagate over long distances, up to 1,500–2,000 km, and penetrate obstacles like buildings, terrain, and even shallow water, making eLoran ideal for urban and maritime environments. Unlike satellites, eLoran uses high-power transmitters, producing a signal millions of times stronger than the weak GPS signals typically received on Earth.

This high signal strength, combined with eLoran’s distinctive pulse-based signal — each station sends a unique pattern — makes it much harder to jam or mimic than GPS, which uses a steady, continuous signal that's easier to interfere with.

The system traces its roots to Loran-C, a Cold War-era long-range navigation technology first developed by the US in the 1950s to guide ships and aircraft across oceans. It operated by sending synchronized pulses from a chain of coastal transmission towers. By measuring the difference in arrival time from multiple stations, a receiver could triangulate its location. While revolutionary at the time, Loran-C was eventually eclipsed by the advent of GPS in the 1990s, which offered greater accuracy and global coverage.

By 2010, most Western countries, including the US, had shut down their Loran infrastructure, deeming it obsolete in the age of satellites. But the vulnerabilities of space-based systems, increasingly apparent in the 2010s, gave new life to the idea of a terrestrial fallback.

Unlike the older system it replaced, eLoran has been modernized with a range of upgrades. It continues to use low-frequency radio signals but now transmits in digital form. Its timing is tightly synchronised with Coordinated Universal Time, ensuring high precision. It also sends correction signals that help fix small errors caused by weather, terrain, or other conditions, making its location data much more accurate.

Thanks to these changes, eLoran can now deliver precise time to within a few nanoseconds and locate positions with an accuracy of 10 to 20 meters in ideal conditions. While this may not match GPS’s sub-meter precision for military-grade applications, eLoran’s robust signals and ground-based infrastructure make it an ideal fallback, immune to satellite-specific threats like orbital attacks or signal interference.

China is no longer treating eLoran as a niche or experimental system. Since the mid-2010s, it has steadily developed a national eLoran network, expanding coverage through a growing number of high-power transmission stations across the country.

While legacy sites in the east anchored early coverage, the real expansion has occurred over the last decade, with new stations constructed in western China.

As of 2024, the network includes at least 20 primary transmission sites, supported by an additional 270+ terrestrial timing nodes linked by a fibre-optic backbone. This land-based infrastructure ensures not only wide geographic coverage but also system resilience. If any one station is disabled, whether by natural disaster or hostile action, others can continue broadcasting, and networked timing corrections can ensure continuity.

To make this terrestrial system interoperable with China’s broader PNT ecosystem, eLoran has been integrated with the BeiDou satellite network and a fibre-linked timing grid.

Multi-mode receivers, capable of processing BeiDou, eLoran, and other signals, automatically select the most reliable source based on real-time availability and integrity checks. For instance, if satellite signals are jammed, these receivers seamlessly fall back to eLoran without user intervention.

The fibre-optic network, spanning over 20,000 kilometres and connecting 294 timing stations, distributes UTC from atomic clocks to critical infrastructure like data centres, military bases, and industrial zones, providing a timing reference independent of both satellite and radio signals.

Advanced PNT fusion algorithms further enhance resilience by combining data from BeiDou, eLoran, inertial navigation systems, and fibre networks, optimising accuracy and continuity across diverse applications.

With the construction of stations in Dunhuang, Korla, and Nagqu, all located in western China, not too far from the border with India, China now has an eLoran network that covers the entire country, giving it what some refer to as a “PNT triad", combining signals from satellites, ground-based transmitters and fibre-optic networks.

The three channels are technically independent, with no shared points of failure. An attack on one, whether through jamming, spoofing or physical sabotage, is unlikely to compromise the others. The result is a hardened, defense-grade system built to absorb strikes and keep operating in contested conditions.

Even though eLoran is not a complete replacement for satellites, it is a formidable insurance policy against disruptions.

The Chinese eLoran system extends 1,500 km offshore, covering the Taiwan Strait, the island of Taiwan, and key surrounding waters.

In a conflict over Taiwan, China could spoof or jam satellite navigation signals across the region. This would severely disrupt US, Japanese, and allied forces that rely on satellite-based PNT for navigation, targeting, and coordination.

Meanwhile, Chinese forces would continue operating with reliable positioning and timing via eLoran.

The resulting asymmetry would give Beijing a major tactical advantage in the early stages of a campaign, allowing it to act quickly and decisively before meaningful outside intervention is possible. And that advantage could be all China needs to tip the scales.