US Prepares for Wars Without GPS as New Clock Technology Could Rewrite the Rules
The Pentagon’s research arm is testing a new generation of ultra-precise clocks in the hope of eventually integrating them into military aircraft and radar systems. The technology is intended to provide US forces with a reliable backup whenever the Global Positioning System, or GPS, is disrupted by jamming or spoofing.
To achieve this, the Defense Advanced Research Projects Agency, known as DARPA, is addressing a vulnerability rooted in a complex and widely misunderstood principle: GPS depends entirely on extremely precise timing, according to US news outlet Business Insider.
“Positioning, navigation and timing are the services we receive from GPS,” said Dana Goward, president of the Resilient Navigation and Timing Foundation.
GPS satellites operate by continuously broadcasting exceptionally precise timestamps, Goward explained. A receiver — whether a mobile phone or a military weapons system — compares signals from several satellites and uses the minute differences in their travel times to determine its location.
However, these signals are extremely weak by the time they reach the Earth’s surface, making them vulnerable to interference, according to Goward. Such interference can be deliberate, as in jamming that prevents a receiver from detecting the signals, or electronic spoofing, which feeds the device false information. It can also occur unintentionally as a result of disturbances caused by natural solar activity.
These disruptions, particularly deliberate interference during wartime, have become an increasing concern for the Pentagon. GPS is now so deeply embedded in both military and civilian technologies that no equivalent alternative can provide the same level of precision, Goward said.
Through its new clocks, DARPA is seeking to strengthen the resilience of the US military’s positioning, navigation and timing capabilities, collectively known as PNT. The research could, however, have broader implications for other GPS-dependent systems, including banking, the internet and power grids.
The agency has already tested the clocks aboard military aircraft, ships and vehicles, moving beyond laboratory trials and into operational environments.
Mukund Vengalattore, a DARPA programme manager, told Business Insider that clocks developed under the agency’s ROCkN programme could maintain GPS-level timing accuracy for more than two or three weeks without requiring resynchronisation.
Comparable technology currently available can preserve that level of accuracy for only a few hours, he added.
The next phase of the initiative, called “It’s About Time”, will focus on making the clocks practical for use outside research environments. It will also assess whether they can be manufactured at scale and integrated into existing military platforms.
Goward said the most advanced clocks currently available face limitations related to their size, weight, power requirements and cost, all of which restrict their practical deployment.
The present challenge is to overcome those constraints. “A prototype is not a technology,” said Vengalattore, who previously served as a physics professor at Cornell University.
A 2021 report issued by a US government watchdog had already raised concerns about military efforts to build a more resilient positioning, navigation and timing architecture.
The report found that no single alternative technology could provide everything the military obtains from GPS, adding that the Pentagon would probably need to pursue several innovative and complementary solutions.
Greater levels of accuracy, such as those potentially offered by DARPA’s clocks, could help the military synchronise information from large numbers of sensors. This has become an increasing concern for forces at every operational level, as improved synchronisation would also enable them to build a coherent picture of battlefield developments more rapidly.
“We know GPS can be jammed and spoofed, and that has an enormous impact on how our military forces operate in what are known as electromagnetically contested environments,” Vengalattore said.
The New York Times recently reported that Russian satellites had caused disruptions to GPS communications in short bursts lasting about ten seconds across various parts of the world since at least 2019. It remains unclear whether those incidents were deliberate, and the brief disruptions do not appear to have caused significant consequences.
According to Vengalattore, if DARPA succeeds in developing the clocks to its target specifications, the technology could ultimately provide not only a reliable alternative to GPS but also timing between 1,000 and 100,000 times more precise than GPS itself.
He said one of DARPA’s current challenges was helping the military establishment understand the implications of such a technological advance.
“This is not only about improving resilience against GPS jamming or spoofing, but also about creating entirely new capabilities that could provide the joint force with a fundamental strategic advantage,” he said.
“We have not thought deeply enough about the question: what could I do better, or qualitatively differently, if I had timing that was superior to GPS?”
“If you have spent your entire life using flashlights and I suddenly give you a high-powered laser, it will not immediately be obvious what you can use it for,” Vengalattore concluded.
