Hybrid PNT Drives Space Defense Shift From Resilience to Advantage
Defense officials push layered Positioning, Navigation, and Timing systems to secure operational edge in contested environments
For decades, Positioning, Navigation, and Timing (PNT) has been treated as invisible infrastructure — an assumed utility delivered primarily through Global Navigation Satellite Systems (GNSS). That era is ending. Defense planners now argue that hybrid PNT architectures are no longer about redundancy alone, but about competitive advantage over adversaries.
The conversation is shifting from “How do we protect GPS (Global Positioning System)?” to “How do we combine multiple sources of timing and positioning to outmaneuver threats?”
The emerging doctrine emphasizes layered systems, fusion engines, terrestrial and satellite alternatives, and faster procurement cycles.
“There is no one size that fits all. It’s about finding the right horse for the right course and determining what you value most and how you fit those things into your requirement,” said Captain Adam Clarke, Deputy Head of Space, C4ISR Branch, Cyber & Specialist Operations Command, UK Ministry of Defence.
Clarke said his focus was on securing PNT advantage, noting that while resilience and hybrid approaches remain central, advantage over an adversary ultimately stems from resilience, situational awareness, understanding vulnerabilities, and selecting the right solution for each operational requirement.
His framing reflects a broader reassessment underway across military and commercial sectors: PNT is no longer a single-source service, but a dynamic ecosystem requiring orchestration.
Beyond Drop-In GNSS
Clarke acknowledged that decades of reliance on GNSS created a culture of convenience.
“We’ve existed in a world where GNSS solutions have been a ready-made drop-in fix for so many applications that we have not had to think about how we employ time, where we take it from, or what our dependencies are,” he said. “We now have an abundance of choices to make.”
That abundance introduces complexity. Instead of a single satellite constellation delivering timing and positioning globally, operators must now weigh trade-offs between medium Earth orbit (MEO) systems such as GPS and Galileo, low Earth orbit (LEO) constellations, terrestrial transmitters, fiber-based time transfer, and signals of opportunity derived from communications satellites.
The shift forces procurement officials and engineers to reconsider assumptions embedded in legacy infrastructure. Much of today’s fixed infrastructure — from defense networks to civil systems — was designed with the expectation that precise timing “just exists.”
“We’re faced with the challenge of a brownfield site,” Clarke said. “Fixing forward is definitely one of the things we can do. But we must also manage our risks today.”
The brownfield problem is particularly acute in defense, where user terminals and waveforms are often locked into long life cycles. Andy Lincoln, Vice-President and Chief Engineer at Viasat, highlighted the tension.
“I don’t want any changes to the user terminals or to the waveforms,” Lincoln said. “And so, how can you make the problem much better? That’s difficult, because you took away most of the free variables.”
Commercial Layers Emerging
While defense grapples with modernization timelines, commercial providers are advancing alternative layers.
Michael O’Connor, Executive Vice President of the PNT Group at Iridium Communications, argued that market realities are already shifting.
“Organizations that rely on PNT need to implement solutions that make it more robust and resilient — and those solutions come in a variety of forms,” O’Connor said.
One major obstacle, however, is economic psychology.
He noted that GPS and other GNSS services are effectively free for end users, which has historically created a barrier for commercial alternatives trying to enter the PNT market.
Iridium’s low Earth orbit satellites operate much closer to Earth than traditional MEO navigation constellations. According to O’Connor, that proximity translates into stronger signals.
“The signal itself is about 30 dB — about 1,000 times stronger than GPS,” he said.
Stronger signals reduce the effective radius of jamming. O’Connor noted that spoofing and jamming incidents are no longer theoretical.
“Eighteen months ago, there were fewer than 1,000 reported spoofing and jamming events per month. Today, that’s over 1,000 events per day,” he said. “We don’t want to give our adversaries the advantage of waiting for a perfect solution.”
His message echoed Lincoln’s broader procurement warning: waiting for an all-encompassing future architecture could expose current systems to avoidable risk.
“Implementing solutions now does not preclude adding additional solutions later,” O’Connor said. “There’s no reason not to start now with solutions that are available today.”
Signals of Opportunity
Another emerging pillar of hybrid PNT is the concept of extracting positioning and timing data from communications satellites.
John-Paul Szczepanik, Chief Technology Officer at ALL.SPACE, described how satellite communications (SATCOM) terminals can act as sensors.
“Maintaining SATCOM in these challenging environments is becoming harder, and satellite communications increasingly rely on PNT to establish a link,” Szczepanik said.
Instead of relying solely on dedicated navigation signals, multi-beam and digital phased-array antennas can analyze Doppler shifts — changes in a signal’s frequency caused by the relative motion between a satellite and the receiver — and angle-of-arrival data from satellites already in orbit.
“If you can look at signals of opportunity — use the information that is out there today in the signals that are up in the sky — you can deliver an alternative PNT solution that is much more resilient,” he said. “It does bring in that hybrid idea, because you’re using everything that’s out there and fusing it together.”
This convergence of communications and navigation reflects a broader technological trend: as more constellations launch for broadband and Earth observation, the sky becomes richer in exploitable signals.
Lincoln added that computing power at the edge is falling in cost rapidly, making fusion engines increasingly viable even for small platforms.
“It’s much better to just do something and to learn from it, and then do something else next year,” he said.
The discussion took place at the Defence In Space Conference (DISC) 2025 in London. The panel was moderated by Lincoln and focused on hybrid architectures and PNT advantage in contested environments.
Clarke emphasized that defense acquisition is evolving toward outcome-based approaches rather than rigid specifications.
“As defense moves toward a more open outcome-based approach, I can see real opportunity for suppliers to identify opportunities to insert resilience and to pick the right sorts of PNT capabilities to make sure the digital fabric of the things being delivered is secure, trustworthy, and safe,” he said.
Rather than issuing detailed prescriptions, defense organizations are increasingly inviting industry to propose integrated resilience layers.
That approach is especially relevant as uncrewed systems proliferate. Autonomous platforms, from small drones to maritime vessels, are expected to form a growing portion of future force structures. These systems demand low-cost, lightweight PNT solutions that can operate in jammed environments.
Hybrid architectures, therefore, must scale across vastly different cost and performance envelopes.
Rapid Iteration
Panelists also stressed that the biggest risk may be waiting too long for a perfect solution.
Lincoln warned that defense procurement often aims to buy systems guaranteed to work for 10–15 years against every future threat, a goal he said is unrealistic in the rapidly evolving electromagnetic environment.
“It’s much better to just do something and to learn from it, and then do something else next year,” Lincoln said.
O’Connor echoed that point, noting that adopting new PNT capabilities today does not prevent organizations from integrating better technologies later.
“Implementing solutions now does not preclude adding additional solutions later,” he said. “There’s no reason not to start now with solutions that are available today.”
Panelists concluded that the next phase will likely involve deeper integration of commercial constellations, software‑defined receivers, and artificial‑intelligence‑driven fusion engines that can automatically select the most reliable timing and positioning signals in real time.
They suggested future PNT architectures may resemble a data network rather than a single navigation system, with platforms switching among satellite, terrestrial, and opportunistic signals as conditions change. If that model takes hold, hybrid PNT could become a flexible infrastructure layer supporting autonomous platforms and resilient communications in contested environments.