When Justin Deifel sat down with Inside GNSS at XPONENTIAL, it was his first media interview since joining Xona as vice president of government programs. The setting was fitting. Xona is moving Pulsar, its low Earth orbit (LEO) PNT service, toward operational status at a time when government, defense, infrastructure and commercial users are reassessing long-standing dependence on GNSS alone.

Deifel joined Xona in May after a career across the U.S. Space Force, Air Force, national security space and intelligence communities. His recent assignments included chief of staff for PEO Space Sensing, squadron commander and materiel leader for Resilient GPS, program manager and materiel leader for the Military SATCOM and PNT Directorate Futures division, and leadership roles supporting MUOS, the Enhanced Polar System Recapitalization and future GPS capabilities. Earlier, he worked at Edwards Air Force Base on test range capabilities and flight test programs, deployed to Afghanistan in support of air operations, led U.S. government and commercial testing related to terrestrial network interference with GPS, and managed elements of the GPS III space vehicle program. 

“Rapid innovation in launch and satellite communications has shown that commercial companies can deliver capability at the speed of relevance,” Deifel said. “Xona is bringing that same approach to rethinking positioning, navigation and timing for the modern era with Pulsar.”

For Deifel, resilient PNT is no longer a future planning problem. “Over the past year, Xona has demonstrated on orbit what many inside government long believed would be impossible: broadcasting a new navigation signal alongside GPS while materially improving signal strength, precision and protection against jamming and spoofing,” he said. “Resilient PNT is not a future requirement. It is an operational requirement now, and Pulsar will be an important part of how that resilience gets delivered.” 

That view reflects Deifel’s experience inside government programs, where promising capability can take years to field. He does not describe Pulsar as a replacement for GPS, GNSS, M-Code or other resilient PNT efforts, but as one layer in a broader architecture.

“Resilient PNT is not an either-or discussion,” he said. “Users benefit from multiple independent sources of PNT capability working together.” 

Pulsar broadcasts in L-band, like GPS, which Deifel said means many existing GNSS devices can add support through software updates rather than new hardware. That integration path is central to his assessment of how new PNT capabilities become useful at scale.

“Having spent years inside government programs, the gap between promising technology and fielded operational capability is often underestimated,” he said. “Adoption depends on integration burden, cost, timelines, and whether users can realistically deploy it across various applications with different requirements.” 

He pointed to M-Code as an example. Although M-Code has been broadcasting since 2005, he said, the government and industry are still building and integrating the user equipment needed to support it, delaying important capability for warfighters. 

Deifel connected those fielding realities to current electronic warfare conditions and drone operations. Many platforms, particularly smaller or attritable systems, need resilient PNT at a size, scale and price traditional modernization pathways may struggle to serve. He described Xona as part of the “future infrastructure,” citing higher power, signal diversity and GPS independence as capabilities increasingly needed by both national security and commercial users. 

“The time is now to begin thinking beyond a single-source PNT architecture,” Deifel said. “Pulsar’s capability will make a measurable difference in performance well before the full constellation is complete, and its value will only increase over time.” 

Recent testing with commercial receiver partners, he added, has shown even one Pulsar satellite augmenting GNSS can improve urban availability and multipath performance, while enabling coarse-location authentication to help mitigate spoofing. 

Max Eunice, a Xona spokesperson, said Deifel joins as Pulsar approaches operational status, with Xona’s manufacturing facility in place and its first production batch of satellites scheduled to launch in October.

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“How was the weather up there?” my friend asked.

I had just finished chairing the last session of the 2026 Munich Space Summit. The final question from the audience was in the nature of “why don’t we have a terrestrial system across most of the globe to back up GNSS and make the world safer?”

That triggered my “preacher mode.” I had mounted my soap box (hence the question about the weather up there) and given a version of my favorite sermon:

“Water and electricity are essential utilities. Today, PNT is also an essential utility, but it is invisible to almost everyone. This invisibility, especially among political leaders and other decision 
makers, is a big obstacle to implementing complementary and backup systems for GNSS. Folks here at the summit are respected experts. You have a duty to share your knowledge and understanding with others, especially national governments. Go forth and tell the story.”

It was very much like the message I offered in 2017, but, nine years later, was a bit more urgent. While the West has seen some movement toward greater resilience since then, one wonders if it is commensurate with the increases in obvious threats and risks.

By the way, to answer my friend’s question—the weather on top of my soapbox usually seems clear. But there is always a chance of rant.

Munich 2017: Admitting a Solvable Problem

The 2026 event was my second time at the Munich summit. The first was in 2017. That year’s theme was “GNSS—Time for a Backup?”

Spoiler alert: The resounding answer from all was “yes!”

I was privileged to chair a distinguished panel asked to discuss the summit’s theme question. The “set up” in the program was:

The Challenge: GNSS has been described as “…a single point of failure for critical infrastructure.” Free and available anywhere with a view of the sky, GNSS timing and location signals have been incorporated into virtually every technology. GNSS service disruptions are caused by natural events, accidents and equipment malfunctions. Malicious acts by nation states, terrorists, organized crime, and “privacy seekers” are a widespread and increasing problem. Many nations are considering establishing terrestrial PNT systems to complement GNSS, or encouraging industry to establish such systems as a partly commercial enterprise. Members of the panel will be asked to describe desirable characteristics of such systems.

Definitions: For the purpose of this panel, “Backup” will be understood to mean one or more PNT systems to complement GNSS services. Complementary systems continuously operate alongside and seamlessly with GNSS and can be integrated in the same timing and navigation receivers.

While it was nine long years ago, the set up and panelists’ observations seem as on point today as they were then. Here is what the experts said nine years ago:

• Dominic Hayes (European Commission) discussed a project that at that point had collected the electronic signatures of over 100,000 jammers in Europe. He called for a comprehensive approach and said more than one complementary system would likely be needed if everyone was to be protected.

• Gian-Gherardo Calini (European GNSS Agency) agreed that more than one backup was needed and urged users to protect themselves.

• Francis Zachariae (IALA) asked who was responsible for protecting GNSS services. He opined that a big obstacle to progress was that we have not had a major failure event. 

• Tony Flavin (Chronos) agreed the lack of a major failure had led to complacency. Also, using multiple GNSS did not provide much protection as most jammers hit all the systems simultaneously.

• Guy Buesnel (Spirent) discussed how spoofing was getting easier and cheaper, and that users need a warning when GNSS is not reliable. He also said spoofing and jamming were impacting aviation safety and operations.

• Professor Per Hoeg (Technical Institute of Denmark) cautioned that not all threat vectors were malicious. Solar activity can also profoundly impact GNSS signals.

• John Fischer (Orolia-Spectracom) discussed the importance of networks and the danger of over-dependence on space-based timing for synchronization.

• Harold “Stormy” Martin (U.S. National Coordination Office) said the U.S. President directed action on a GPS backup in 2004 and Congress had recently reinforced the need. His government was developing system requirements. It was long past time for a backup, he said.

Side discussions (often the most productive at such events) focused on technical mitigations and solutions. Galileo’s Public Regulated Service (PRS) service, ideas for low Earth Orbit (LEO) PNT, and terrestrial systems.

One attendee, Reelektronika’s Durk Van Willigen, even showed off an integrated GNSS/eLoran/Chayka receiver only 6 cm long. His company had developed it to meet what they saw as an emerging need.

The mood at and coming out of Munich 2017 was one of concern and expectation. The issues were clear and well understood. Yet, this was a solvable problem. Importantly, leadership in the European Union (EU) and U.S. were working on it. 

Munich 2026: “How Do We Get There?”

Concerns expressed in 2017 were well represented and amplified at this year’s Munich Space Summit. Mentions of jamming, spoofing and other interference were ubiquitous and almost offhand. In 2026, disruption is no longer unusual. It is a normal part of the environment.

Yet, the agenda did not address the question of whether one or more complementary systems were needed to protect GNSS and users. It was an assumption in nearly every panel, every presentation, and every comment. 

Panel topics included phrases like “resilient navigation, “multi-layer PNT” and “multi-faceted PNT.” Difficult times and the need for trust were regularly mentioned.

And, in a surprising parallel to 2017, an attendee at the event’s grand evening reception had his newest micro receiver with him to show around. Trevor Landon gave me a look at the new Iridium ASIC. 

Recognition of the need for complements and alternatives to GNSS was universal. There was less agreement on which systems should be implemented.

But this was to be expected. Many, if not most, attendees have already decided on their favorite system. They’ve dedicated years of effort to developing and understanding their technology, have a substantial financial interest in its success, or both. And the systems discussed were overwhelmingly space-based or space-dependent. Which made perfect sense. It was the Munich Space Summit, after all. 

Progress Since 2017

The last day, last panel, and last question of the summit was why, nine years later, we have not done more about complementing and backing up GNSS. 

For the previous two and a half days, incredibly intelligent and capable people had affirmed the need and demonstrated that a wealth of solutions are available. 

Private and government studies in the West have shown the value of combining signals from space, terrestrial broadcast, and fiber-based timing. This “resilient triad” can create a national PNT architecture that is very difficult to disrupt. Extant systems in China, Russia, South Korea, and elsewhere are exemplars of what’s possible.

Many rightly question why the West hasn’t made more of a start. In fairness, some projects are underway, and others are emerging.

The EU is exploring LEO PNT and launched the first two Celeste satellites the day after the summit closed. U.S. companies Xona Space Systems and TrustPoint have made their business cases and are in the early stages of building their constellations. 

Scandinavia is building out a fiber timing network connecting Sweden, Finland and Norway. There are papers and proposals for the EU to do the same thing on the continent.

Baltic nations have extensively tested R-mode for maritime. The European Aviation Safety Agency has issued an action that suggests examining additional navigation sources, though such a study would be done in the distant future.

More proactively, the United Kingdom is the first Western nation that’s committed to establishing a coherent and integrated resilient PNT triad. A fiber timing network with three centers spread across Britian is being implemented. It will feed users directly and support a terrestrial broadcast eLoran network that will serve the entire nation and most of the North Sea. The UK government is also investing in LEO PNT. 

While less public about its plans, France has recently joined the UK in its eLoran project. Depending on the scope of the French effort, the two systems could provide high-power terrestrial broadcast time to most of Western Europe. This signal at 100kHz would presumably complement France’s existing 162kHz time signal. Also, the Paris Observatory has been forward leaning on international time synchronization over fiber. It has established synchronizing optical fiber links with laboratories in the United Kingdom, Italy and Germany.

But Is It Enough?

One can rightly ask if enough has been done in enough places. 

Has Europe progressed far enough and in enough ways to mitigate the risk of daily minor disruptions and the much greater risk of PNT denial in struggles between major powers?

And what of the inter-dependent world writ large? 

Major economies in the United States, Japan, India, Brazil, Canada, Australia, and Mexico seem to still be overwhelmingly dependent on highly vulnerable signals from space. For smaller economies, the idea of sovereign, resilient PNT to complement GNSS may not even be a “someday” vision.

Yet, there are very, very few among the world’s eight billion people who don’t depend on uninterrupted PNT service in their daily lives. For many, the possibility of a major GNSS disruption is an invisible sword of Damocles.

And let’s all remember, as those who understand the issues, our duty to speak up and share our knowledge and concern. Too often I hear that such issues are “above my paygrade.” If your boss doesn’t know the problem and isn’t concerned and involved, then this issue is exactly at your pay grade. You have a duty to speak out.

Let’s strive to ensure the next nine years see more progress instituting widely adopted resilient PNT than we saw in the last nine. We owe it to ourselves and the world we serve.

OK, now the weather atop the soap box seems like it is turning to rant. So, as they say in church, here endeth the sermon. Go in peace. 

The post Munich 9 Years On: Same Message, More Urgency appeared first on Inside GNSS - Global Navigation Satellite Systems Engineering, Policy, and Design.

Attacks on GNSS are no longer simply a nuisance or a trivial disruption we can afford to ignore. Spoofing and jamming have become increasingly widespread, driving economic losses and costing lives, both in military operations and in civilian settings. Now, more than ever, we need to look closely at backup and complementary solutions that can fill the voids when GNSS falls short.

I recognize this may come across as cliché; however, in this case, it is not. The threat is real. The urgency is real. And the consequences of inaction are becoming harder to ignore.

Low Earth orbit, or LEO, positioning, navigation and timing (PNT) may be one of the most important answers. Commercial companies are creating mega-constellations to harness the many advantages of LEO, and it has become clear that LEO satellites could play a major role in future PNT architectures. In some applications, LEO could complement GNSS. In others, it may provide a space-based alternative when GNSS is degraded, manipulated or denied altogether. There is a lot of interest and excitement around LEO in the industry, and for good reason. It is an emerging area that many of us are studying with intensity and enthusiasm. But there are different schools of thought on how best to leverage LEO PNT, and the path forward comes with its own technical, operational, commercial and regulatory challenges.

That is why this column is born and will exist in every edition. 

Inside LEO will explore how LEO systems are reshaping PNT, communications, resilience and the broader architecture of space based services. LEO is not just another orbit. It changes the signal environment, the economics, the business model and, potentially, the way users think about trust in PNT.

But let’s be clear: LEO PNT is not a new, revolutionary concept. In fact, the first satellite navigation system, Transit, was a LEO system developed in the 1960s. Through Transit, we learned that LEO PNT is both a blessing and a curse.

It is a blessing because of speed, geometry and signal strength. LEO satellites are closer to Earth and move quickly across the sky. Those characteristics can be extremely useful for navigation. But LEO is also a curse because it requires a large number of satellites to provide persistent, useful coverage. During the Transit era, users often had to wait an hour or more to get a position fix. That was not exactly ideal then, and it is certainly not acceptable for the world we live in today.

To address the LEO curse, we needed a very large number of satellites, which was not feasible given launch capabilities in the 1960s. That is why GPS quickly became the dominant PNT system. A medium Earth orbit (MEO) architecture, where GPS operates, achieves comparable performance with an order-of-magnitude fewer satellites than would be needed in LEO. GPS’s design mitigated the problem of slow position fixes while still delivering high accuracy and continuous global coverage. Yes, GPS had limitations, particularly in urban canyons and indoors, but those were limitations users could often live with or augment using localized sensors.

For decades, GPS and then GNSS were enough for many applications.

In an ideal world, it might have stayed that way. But times have changed. GNSS alone is no longer enough.

The Emergence of LEO PNT

Two things happened simultaneously and independently: the rapid development of autonomous systems and continuous, escalating attacks on GNSS. Autonomous platforms exposed the limits of GPS alone in safety critical, dynamic environments. At the same time, spoofing and jamming became easier, more accessible and more prevalent, both in military theaters and in civilian life.

The PNT community realized something had to change. The search for complementary and backup solutions became urgent. LEO PNT emerged as one of the most intriguing options.

Although satellites started to launch into LEO in significant numbers in the late 1990s, interest in LEO PNT did not really accelerate until around 2017 or 2018. That was when Starlink announced plans to put nearly 12,000 satellites into LEO. This was significant because, at the time, there were not even close to 12,000 satellites in all of LEO combined.

Many people thought that target number was wishful thinking. I took it seriously and started studying LEO PNT with existing constellations [1].

My lab started with Orbcomm satellites and developed the simultaneous tracking and navigation (STAN) approach to address their poorly known signal, ephemerides and timing [2, 3]. In 2018, we conducted the first post-Transit LEO PNT experimental demonstration with non-cooperative satellites, where we navigated an unmanned aerial vehicle (UAV) by exploiting Orbcomm LEO signals of opportunity. We experienced first hand experimentally the curse that had plagued LEO in the past. Our navigation solution began to degrade after about 30 seconds (Figure 1) [4]. We also drove a vehicle in Southern California for a few kilometers. The errors were on the order of hundreds of meters (Figure 2) [1].

So, yes, LEO can give you a navigation solution. But with sparse constellations and limited observability, it is not necessarily accurate enough for many modern applications. That changes when you add satellites. Many satellites (Figure 3).

When there are thousands of satellites in LEO, the geometry, availability and signal opportunities begin to change dramatically (Figure 4). You start to get performance that can become comparable to GNSS in certain respects and potentially superior in others. That is what makes mega constellations a game changer for LEO PNT.

Right now, GNSS is the only truly global sensor. LiDAR, vision and radar are powerful, but they are proximity sensors. They can help keep you from colliding with a car or a building, but they do not readily place you directly in a global reference frame. They also do not work equally well in every environment. If you are in an aircraft at 38,000 feet or flying over an ocean with no features, how much can vision help you? If you are operating in a feature poor, denied or degraded environment, what sensor gives you global context?

That is the promise of space based PNT. And LEO, if we learn how to use it properly, can provide a new and powerful layer in that architecture.

The Reason LEO is so Compelling Starts with Physics

LEO satellites are much closer to Earth than GNSS satellites in MEO. Because they are closer, their signals are generally received at higher power. That matters. Higher received power can make a signal more useful and more resilient, particularly in difficult environments.

LEO satellites also move much faster across the sky than GNSS satellites. This faster motion means Doppler becomes highly informative for positioning and navigation. With GPS, Doppler can be useful, but the system is primarily built around pseudorange and carrier phase. With LEO, the fast motion of the satellite itself becomes a major source of navigation information.

Then there is bandwidth. Some LEO communication signals are much wider than traditional civilian GNSS signals. Wider bandwidth can provide better resolution and more precise time estimation. When higher bandwidth is combined with higher received power, fast satellite motion and large numbers of satellites, the PNT opportunity becomes very interesting.

LEO also changes the frequency picture. GNSS is concentrated in the L band. LEO systems operate across a much more diverse set of frequencies. Some are in VHF. Some are in L band. Some are in C band. Many are in Ku and Ka band. This matters because frequency diversity can contribute to resilience. If we limit ourselves to one band, we leave one of LEO’s great advantages on the table.

This is an important point. Many people involved in LEO PNT also worked on GNSS, and there is a natural tendency to duplicate as much of the GNSS model as possible while fixing the most obvious shortcomings. I understand that instinct. But if we are starting fresh, why limit ourselves to one band? Why ignore the signal diversity that LEO offers?

Which band is best? That is hard to say. Some companies favor C band. Others favor L band because it allows users to leverage GNSS antenna infrastructure. Ku and Ka band systems are seeing enormous growth because so many broadband satellites operate there. Whether you like those bands or not, they are going to be a force to be reckoned with.

That is the beauty of LEO. It gives us options. It gives us signal diversity. It gives us Doppler. It gives us stronger signals. It gives us large numbers of satellites. And, used intelligently, it can provide a much needed layer of resilience.

But LEO PNT is not one thing. That is where the taxonomy matters.

The Various Schools of Thought

There are several schools of thought on how LEO should be used for PNT: dedicated, dual purpose, augmented and opportunistic.

The first is dedicated LEO PNT. These are constellations designed specifically to provide PNT from low Earth orbit. Companies such as TrustPoint and Xona are examples. Their systems are built around navigation as the primary mission. This approach has the advantage of intentional design. The signals, payloads, constellation architecture and user equipment can be optimized for PNT. The challenge is scale, adoption, service continuity and the need to build an ecosystem from the ground up.

The second model is dual purpose LEO PNT. In this approach, PNT is paired with another primary service, such as communications. A satellite may be transmitting a communication signal that can also support positioning, navigation or timing. Iridium and Globalstar are examples of constellations that dual-purposed their satellites for PNT. Starlink and Amazon LEO appear to be headed that way. The attraction is obvious: If the satellite infrastructure is already being deployed for communications, perhaps PNT can ride along. The challenge is the signal, business model and operational priorities may not be designed for PNT users first.

The third model is augmented LEO PNT, where LEO is not necessarily a standalone replacement for GNSS. It is part of a multilayer architecture that works with GNSS and other PNT sources. This is where Europe is headed with Celeste, an in orbit demonstrator mission that will feature an 11 satellite constellation. Celeste helps when she can, but she is not positioned as a full standalone global replacement for GNSS. This model may be especially important because the future is unlikely to be one system replacing another. It is more likely to be layered, hybrid and context dependent.

The fourth model is opportunistic LEO PNT. This is the broadest and, in some ways, the most interesting category. Opportunistic PNT can include dedicated, dual purpose or augmented systems, but it can also include signals that were never designed for PNT at all. A communications satellite constellation may not transmit anything intended for navigation, but its signals can still be leveraged for positioning and timing if we know how to use them. Starlink and OneWeb are examples often studied in this context.

A New Way of Thinking About PNT

The shift to LEO also introduces complications GNSS users are not accustomed to thinking about. GPS is a government system. It is offered as a free service. It is mature, open, globally integrated and deeply embedded into receivers, systems, standards, operations and user expectations. GPS is also self contained. A user can wake up a receiver and obtain the information needed to use the constellation. LEO is a different ball game.

Many LEO PNT approaches are commercial or non governmental. That changes the landscape from the user’s point of view. What happens if your subscription lapses? What guarantees do you have that the company providing your PNT service will still exist in five years? What if it is acquired? What if prices rise? What if the service changes? What service level commitments are available? What happens in safety critical applications? How will spectrum licensing work? What does signal access look like? How will standards and interoperability evolve?

These are not side issues. They are central to the future of LEO PNT.

The transition from government provided GNSS to commercial or hybrid LEO services is not only a technical shift. It is an institutional shift. Users who have spent decades relying on open GNSS signals will now have to think about contracts, subscriptions, service guarantees, business continuity, liability, receiver access and long term trust.

Commercial LEO PNT remains a compelling and necessary part of the future PNT landscape. But the industry must be clear-eyed about what changes when PNT becomes part of a commercial service architecture.

Where Will LEO PNT be Used First?

It will first be leveraged where the loss of GNSS hurts the most. Defense, safety-of-life and mission critical applications will be major drivers of adoption, although some sectors, such as aviation, will be difficult to change because of certification, regulation and long equipment cycles.

Drones represent lower hanging fruit. They are critical systems, but they can be adapted more quickly than legacy aviation systems. The market is still developing. Many platforms and operational models are still being built. I expect to see meaningful adoption there, and not just in small drones. Larger unmanned aircraft will also begin leveraging LEO PNT. Some defense applications are already moving in this direction, and that will rapidly grow.

Maritime is another important area. It is heavily regulated, but the need is clear. GNSS interference at sea is already a serious problem, and maritime users need resilient alternatives that can support navigation, timing and situational awareness.

The next wave will likely include autonomous systems and self driving vehicles, although I do not see automotive adoption as immediate. The need will grow as autonomy matures and as platforms require resilient global positioning beyond what proximity sensors can provide.

Eventually, LEO PNT will be integrated into smartphones. There will also be a major push through 6G to make positioning and communications more deeply intertwined. That convergence is coming, and LEO will be part of it.

Regardless of how adoption unfolds, the need is clear. GNSS jamming and spoofing are becoming more sophisticated and more prevalent in Ukraine, the Middle East and other regions. Organized crime and other nefarious actors are capitalizing on GNSS vulnerabilities in the civilian world. Unintentional interference is also a growing problem. Lives are being lost. Damage is being done. And the situation will only get worse if we do not act.

Autonomous systems first forced the PNT community to confront the limitations of GNSS alone. Jamming, spoofing and interference then exposed vulnerabilities that can no longer be treated as rare exceptions. We need complementary systems. We need backups. We need resilience. We need architectures that do not fail catastrophically when GNSS is denied or manipulated.

Why LEO, Why Now 

LEO has been born again at the right moment. The surge in satellites has made LEO an attractive option for space based PNT. The signals are stronger. The satellites move faster. The bandwidths can be much wider. The frequencies are more diverse. The number of potential signals is growing dramatically. And unlike terrestrial alternatives, LEO has the potential to provide broad, space based coverage that can complement GNSS at scale.

The question is simple: We have mega constellations in LEO. Why not use them?

LEO PNT is an emerging area, and it is changing constantly. Inside LEO will help readers understand what is real, what is hype, what is technically possible and what still needs to be solved. In future columns, I will dive deeper into LEO fundamentals, deployment models, the current state of LEO, user demand, operational adoption, signal design, standards, interoperability and the future of resilient PNT.

GNSS transformed the world. But the world GNSS helped create now demands more than GNSS alone can provide.

That is why LEO matters. And that is why we need to understand it now. 

References

(1) Z. Kassas, J. Morales, and J. Khalife, “New-age satellite-based navigation—STAN: simultaneous tracking and navigation with LEO satellite signals,” Inside GNSS Magazine, Vol. 14, Issue 4, Aug. 2019, pp. 56-65.

(2) J. Khalife and Z. Kassas, “Receiver design for Doppler positioning with LEO satellites,” Proceedings of IEEE International Conference on Acoustics, Speech, and Signal Processing, 2019, pp. 5506-5510.

(3) J. Morales, J. Khalife, and Z. Kassas, “Simultaneous tracking of Orbcomm LEO satellites and inertial navigation system aiding using Doppler measurements,” Proceedings of IEEE Vehicular Technology Conference, 2019, pp. 1-6.

(4) J. Morales, J. Khalife, A. Abdallah, C. Ardito, and Z. Kassas, “Inertial navigation system aiding with Orbcomm LEO satellite Doppler measurements,” Proceedings of ION GNSS+ Conference, 2018, pp. 2718-2725.

ZAHER (ZAK) M. KASSAS is a global leader in resilient and alternative PNT. He is the TRC Endowed Chair in Intelligent Transportation Systems and a Professor at The Ohio State University. He is the Director of the U.S. Department of Transportation Center for Automated Vehicle Research with Multimodal AssurEd Navigation (CARMEN+) and Director of the Autonomous Systems Perception, Intelligence & Navigation (ASPIN) Lab. A Fellow of IEEE and ION, he has authored over 200 publications and holds multiple patents. He was awarded by President Biden the Presidential Early Career Award for Scientists and Engineers (PECASE), the highest honor bestowed by the U.S. government on outstanding scientists and engineers; the IEEE AESS Richard Kershner Award for pioneering contributions to the theory and practice of PNT with terrestrial and non-terrestrial signals of opportunity; and more than 60 scientific and governmental awards. He was ranked as the top scholar globally in the field of Navigation. His research has attracted more than $28 million in competitive grants; has been featured in dozens of international media outlets; and has shaped government programs, policies and investments.

The post Inside LEO: LEO PNT – Why Now? appeared first on Inside GNSS - Global Navigation Satellite Systems Engineering, Policy, and Design.

Twenty years on, Galileo stands as both a major European achievement and a hard-won lesson in what it takes to build sovereign, resilient and globally relevant navigation infrastructure. Hein will examine the decisions, compromises and challenges that shaped the system, offering readers a rare behind-the-scenes perspective on Europe’s strategic choice to move from dependence to capability—and why that story still matters now.

Highs and lows in the development of the European Satellite Navigation System, Galileo. 

For much of the late 20th century, the world had access to only one fully operational global satellite navigation system: the United States’ Global Positioning System (GPS). Conceived in the 1970s as a military asset and declared fully operational in 1995, GPS had by the mid-1990s become indispensable to civilian users worldwide—from pilots and ship captains to farmers, surveyors and ordinary motorists. Yet, beneath the convenience of free, open signals lay a profound strategic vulnerability: GPS was owned, operated and controlled exclusively by the United States Department of Defense (DoD). Washington could, in principle, degrade or deny the signal at will.

This dependency troubled European policymakers and military planners throughout the 1990s. The concern was not merely theoretical. During the Gulf War of 1991, the United States deliberately degraded GPS accuracy through a technique known as Selective Availability, limiting civilian precision to roughly 100 meters. Although Selective Availability was switched off in May 2000, the capability to reinstate it remained. European governments, aerospace industries, and transport authorities recognized that building critical infrastructure—aviation, rail, maritime, precision agriculture, financial timing networks—on a foreign-controlled system was a risk that strategic autonomy could not tolerate.

Early Studies and the Political Will to Act

European interest in an independent navigation capability had simmered since the 1980s. The European Space Agency (ESA) had developed NAVSAT and GRANAS concept studies, and various national programs explored augmentation systems. A concrete step came with the European Geostationary Navigation Overlay Service (EGNOS), developed jointly by ESA, the European Commission (EC), and Eurocontrol from the mid-1990s. EGNOS, which became operational in 2009, could improve GPS accuracy and provide integrity signals for safety-critical applications, but it remained dependent on the underlying GPS constellation. It was a patch, not a solution.

The decisive political turn came in the second half of the 1990s. The European Commission’s 1999 communication, “Galileo: Involving Europe in a New Generation of Satellite Navigation Services,” laid out the case openly: Europe needed its own system, civilian-controlled and commercially oriented, interoperable with GPS but independent of it. The name Galileo, a tribute to Galileo Galilei, an Italian astronomer who made foundational contributions to the science of motion and observation, was chosen to signal both scientific heritage and a new era of European technological ambition. (I believe Kepler would have been the better name. But politics had decided, not technology!)

The Early Days of Galileo: 1999-2000 Political Launch and National Ambitions

The story of Galileo’s political birth is, in many respects, the story of a European pilgrimage. This was the first generated “income” of Galileo: however, not for the space system but for the Galileo Travel Agency! In 1999 and 2000, delegations, lobbyists, industry representatives, and national officials from across the continent converged on Brussels with a shared ambition but—as would quickly become apparent—with rather different ideas about what that ambition should deliver. The atmosphere was one of excitement tinged with opportunism: here was a major program taking shape, and every stakeholder wanted a seat at the table. 

The process generated what insiders sometimes called national “wish lists”—catalogues of desired outcomes, preferred industrial workshares, and projected economic benefits that each member state hoped to extract from the new system. These lists were gathered under various headings and studies. The Galileo Overall Architecture Definition (GALA) study was among the most prominent. GALA was intended to define the overall system architecture, but it also became a vehicle through which competing national interests were channelled into the technical debate. The result was a negotiating process as much as an engineering one.

The official justifications advanced for building Galileo were numerous and, on close inspection, of uneven quality. Safety of life, employment creation, industrial spin-offs, enhanced road and rail navigation, search and rescue improvements, integrity, public-private partnership—all were cited, sometimes with statistics that did not survive scrutiny. Several of the arguments were, frankly, either misconceived or greatly exaggerated, and those with a critical eye could see the economic forecasts in particular owed more to political necessity than to rigorous analysis. The need to justify a multi-billion-euro public investment demanded a compelling narrative, and not every element of that narrative was equally well-founded.

Beneath the rhetoric, however, two motivations stood out as genuinely sound. The first was the desire to break the GPS monopoly. At the turn of the millennium, the entire world depended on a single navigation system owned and operated by the United States DoD. The vulnerabilities this created—strategic, commercial and operational—were real, and no amount of goodwill between allies could fully substitute for an independent capability. The second motivation was equally clear-eyed: Galileo was to be Europe’s ticket into the front rank of high-technology infrastructure. Satellite navigation was not merely a useful service; it was becoming the invisible foundation of the digital economy, and Europe’s long-term competitiveness depended on being a provider rather than merely a user of that foundation. These two reasons, strategic independence and technological leadership, were, in the end, the ones that mattered, and they were sufficient.

An American colleague told me: “I thank Europe for the decision to build up its own satellite navigation system: This was the best investment in GPS. We have never seen so many improvements in GPS after a while of stagnation.”

The Lisbon Treaty and European Space Governance

Before continuing the discussion about the early days of Galileo, I must mention an important political move of the European Union (EU) and its Member States. The Lisbon Treaty, which entered into force in December 2009, marked a turning point in European space governance by providing, for the first time, an explicit legal basis for space activities at the Union level. The key instrument is Article 189 of the Treaty on the Functioning of the European Union (TFEU), which authorizes the EU to develop a European Space Policy aimed at promoting scientific and technological progress, strengthening industrial competitiveness, and supporting the implementation of broader Union policies.

On this basis, the EU may establish a European Space Programme and adopt the necessary legislative measures (regulations, directives and decisions) through the ordinary legislative procedure. In terms of the division of competences, however, space occupies a carefully circumscribed position. Although it falls within the category of shared competences, it is in practice treated as a “support or coordination competence.” The Treaty explicitly prohibits the harmonization of national laws and regulations, preserving the legislative autonomy of Member States in the field.

The Treaty recognizes the security and defense dimensions inherent in space activities. Because space infrastructure is frequently dual-use in nature, serving both civilian and military purposes, the Treaty permits, and in certain respects requires, the EU to address these dimensions as part of a comprehensive space policy. This provision has taken on growing practical significance as Europe’s dependence on space-based services for defense, border management, and crisis response has deepened.

Finally, the Treaty also mandates that the Union establish appropriate relations with the ESA, acknowledging ESA’s longstanding role as Europe’s principal space organization and the need for coherent institutional cooperation between the two bodies.

The Treaty also codifies, at least implicitly (and theoretically), a division of labor between the EU and ESA that has evolved over decades of institutional practice. The EU concentrates on space policy, program funding, and the demand side of the equation, defining what services are needed and ensuring they are delivered to users. ESA, by contrast, remains primarily responsible for the supply side: the engineering, infrastructure, and technical development that make those services possible. The two organizations should be complementary rather than competing.

My impression is the ESA underestimated the implications that were arising over the following years and remained silent. At first glance, it seems quite natural for the EU to be responsible for space policy, taking up the needs of the European community and preparing funding for space activities, while the ESA takes responsibility for technical realization. Unfortunately, the boundary between their respective roles has not always been free of friction and has led many people to a perceived disempowerment of ESA in some directories. I will later come back in detail what is meant with this statement.

One of the Treaty’s most consequential constraints is precisely what it does not permit. The EU has no power to impose harmonized space regulations on its Member States: national space law remains firmly within the sovereign remit of each country. This limitation reflects the broader constitutional settlement of the Lisbon Treaty, which sought to expand Union competence in space while simultaneously protecting the regulatory independence of member governments. The practical effect is a patchwork of national licensing regimes and liability frameworks sitting alongside, but not superseded by, European-level policy. In fact, one can still observe space activities in the Member States, which are duplicating efforts of the EC or even competing by building up similar satellite navigation or satellite communication systems.

Since 2009, the EU’s engagement with space has also acquired a markedly more security-oriented character. The dual-use nature of space infrastructure—navigation, Earth observation, and satellite communications all serving both civilian and defense purposes—has increasingly drawn space policy into the orbit of broader strategic autonomy debates. Protecting European space assets from jamming, spoofing, cyber intrusion, and anti-satellite threats has moved from the margins to the mainstream of EU space thinking, reflecting a wider recognition that space is no longer a benign domain but a contested one in which Europe’s ability to act independently depends on the resilience and security of its own infrastructure.

According to its convention, the ESA is limited to “exclusively peaceful purposes.” However, under pressure from the EU, this term has increasingly been interpreted to also allow for “defensive” military aspects (e.g., surveillance or encrypted communications).

The Decision to Build Galileo

The formal decision to proceed with Galileo was taken by the European Council in March 2002, when EU transport ministers gave their approval for the development and deployment phase of the system. This followed years of preparatory studies, feasibility assessments, and political negotiation, and it represented a definitive commitment by the Union to invest in an independent satellite navigation capability. The EC and the ESA were tasked with jointly overseeing the program, with ESA taking the lead on the technical and procurement side while the EC held overall political authority. A dedicated management structure, the Galileo Joint Undertaking, was established in 2002 to coordinate the two institutions and to manage the program’s early phases.

Costs and Funding

The original cost estimates for Galileo were, in retrospect, optimistic. The development and in-orbit validation phase was initially budgeted at approximately €1.1 billion, with overall deployment costs for the full constellation estimated at around €3.2 billion. These figures reflected the assumptions of the early 2000s, including the expectation that a substantial share of the funding would come from private industry through a public-private partnership (PPP) model. Under this model, a private concession holder was to operate the system commercially and recover costs through service revenues, with public funds covering only a portion of the investment.

I live in a town south of Munich. At the same time as the Galileo decision, a family-owned pharmaceutical company that produced generic medical drugs and had about 100 employees was sold to a multinational medical company for more than 6 billion Euro—just two Galileo systems (cost assumption early 2000s)!

Civil Control, Military Reality and the Question of Dual Use

One of the most deliberate and politically significant design choices made for Galileo was the insistence that it be a civilian system under civilian control. This was not merely a technical or administrative detail; it was a statement of principle, and it was intended to distinguish Galileo fundamentally from GPS. The United States’ system had been conceived as a military asset, and its civilian use, however widespread, remained conditional on the goodwill of the U.S. DoD. Galileo, by contrast, was to be governed by the EC, a civilian institution, and its primary purpose was defined in terms of civilian applications: transport, agriculture, timing, search and rescue, and commercial services.

This civilian identity was not, however, synonymous with exclusion of the military. European policymakers were candid from the outset that defense and security forces would be entitled to use Galileo signals, including the encrypted Public Regulated Service (PRS) reserved for government-authorized users. The formulation that became standard in policy documents was straightforward: Galileo is a civil system under civil control, and the military may use it. This formula allowed Europe to maintain its civilian branding while acknowledging the inescapable reality that any global navigation system is of strategic value, and that European armed forces and security agencies would naturally make use of a European system. 

What happens to the civil control of Galileo in times of crisis? Most European Member States have a Radionavigation Plan that makes clear that, when it comes to the crunch, the military has the final say. The tension between Galileo’s civilian identity and the realities of national security has therefore never been fully resolved; it has merely been deferred.

The PRS was conceived as a government-controlled, encrypted service for authorized institutions—customs agencies, specialized police units, border control, and similar bodies—with strictly limited access. Some nations, however, lobbied for PRS access to be extended to fire brigades and other local emergency services, apparently overlooking the fact that the number of simultaneous users the system can support is not unlimited, and a large number of users might create a problem for security. The military, meanwhile, was not explicitly named among the intended users—the working formula remained the familiar one: they may use it—even though the PRS was developed to a specification, and at a cost, that closely mirrors a military-grade service. The omission was not accidental; it reflected the political sensitivity of departing too visibly from Galileo’s declared civilian character.

Adding a further layer of complexity, most European nations had already concluded Memoranda of Understanding with the United States for the use of GPS, particularly within the NATO framework. Against that background, Galileo’s PRS was initially regarded by many European military establishments as superfluous—a costly duplication of a capability they already accessed through their American alliance commitments.

The world has changed substantially since those early design decisions were made. The conflicts and wars of recent years and today have made clear Europe can no longer take its security for granted and must rebuild defense capabilities that were allowed to atrophy significantly after the end of the Cold War. In that context, an independent, European-owned global satellite navigation system such as Galileo is plainly a major strategic asset for modern defense—essential for the guidance and operation of aircraft, naval vessels, armoured vehicles, and precision weapons alike. 

It is, therefore, even more remarkable that Galileo has not yet been officially designated as a dual-use GNSS. Every other global and regional satellite navigation system—GPS, GLONASS, BeiDou, NavIC—carries an explicit dual-use status. Galileo’s continued omission from that category is increasingly difficult to justify, and the argument for formally recognizing what has always been true in practice grows stronger with every passing year.

A further technical observation is warranted in the context of the PRS. Given that the PRS encryption is not watertight, the signal can be tracked without knowledge of the access code, so-called codeless tracking. One is therefore entitled to ask: What is the justification for the extraordinarily expensive and complex national access key schemes, which differ from country to country? I hope the second generation of Galileo will overcome that problem.

Opening Galileo to the World: International Partners

From an early stage, the EC pursued an active strategy of inviting third countries to join Galileo as partner nations and stakeholders. The rationale was partly financial—contributions from partner countries would help share the costs of development—and partly strategic. A system with broad international participation would be more difficult to challenge or marginalize, and would generate a larger global user base, strengthening the commercial case for European industry.

China was among the earliest countries to engage substantively with the program: A cooperation agreement with the Chinese government was signed in 2003, and China initially contributed funding and participated in technical working groups, though its involvement later diminished as Beijing’s own BeiDou navigation system matured. Israel signed a cooperation agreement with the EU in 2004, becoming one of the first non-European partners to formalize its engagement with the program. Ukraine, Morocco and South Korea also concluded first political agreements in the mid-2000s, each bringing different motivations—industrial participation, regional positioning, or access to high-accuracy services. However, it did not come to the second agreement defining the operational engagement in Galileo. India entered into discussions with the EU during the same period, reflecting the interest of major spacefaring nations in securing a stake in the emerging global navigation landscape. 

Together, these early partnerships gave Galileo an international footprint from the outset and underscored the EC’s ambition to build not merely a regional system, but a genuinely global one. 

PROF. DR.-ING. HABIL. DR. H. C. GÜENTER W. HEIN, Emeritus of Excellence at Bundeswehr University Munich, draws on more than two decades of first-hand experience to recount the development of Galileo, the European satellite navigation system. His involvement began with national research conducted between 1995 and 2008 at his former Institute of Geodesy and Navigation at Bundeswehr University Munich, funded by the Deutsches Zentrum für Luft- und Raumfahrt (DLR, German Aerospace Center). From 2000 onwards, he represented Germany in various EC Galileo study groups, including the Galileo Signal Task Force, and took part in the EU-US negotiations on GPS/Galileo interoperability from 2000 to 2005. He subsequently joined the European Space Agency as Head of the EGNOS and Galileo Evolution Programme Department from 2008 to 2014. He later served as a member of the Executive Board of Munich Aerospace e. V. and has provided consultancy to leading European satellite navigation companies. Güenter W. Hein is the founder of the Munich Satellite Navigation Summit and the Munich New Space Summit, which were merged in 2026 to form the Munich Space Summit. Through all these roles, he has played a central part in shaping European satellite navigation over the past 20 years.

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The work centers on GPS technologies that underpin U.S. military operations, allied forces, and critical infrastructure. Apogee will deliver technical expertise and mission support across Wright-Patterson Air Force Base in Ohio, Robins Air Force Base in Georgia, and Eglin Air Force Base in Florida, working in collaboration with the Air Force Life Cycle Management Center to advance next-generation PNT solutions and improve system performance and reliability.

The award comes as DoD continues to evolve its acquisition strategy for resilient PNT capabilities, with the task order specifically targeting enhancements to existing GPS control systems and accelerated delivery of operational capabilities following recent shifts in that approach.

“This award reflects both the urgency and importance of delivering resilient PNT capabilities to the warfighter,” said Frank Varga, CEO of Apogee. “Our team remains steadfast and committed to evolving the way the Department acquires and advances its weapons systems.”

Apogee describes itself as a multi-domain firm with expertise in digital transformation, science and technology, adaptive acquisition, and mission operations. The company said it is actively hiring across those domains to meet growing program demands.

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Announced at the European Navigation Conference 2026 in Vienna, Precise+ extends FocalPoint’s patented Supercorrelation platform into the carrier phase domain, directly targeting the cycle slips that cause RTK and PPP systems to lose lock in urban canyons, under foliage, and in multipath-heavy environments. When carrier phase lock is interrupted — a routine occurrence in dense cities and under tree cover — receivers suffer cycle slips and force reinitialisation, the defining barrier to deploying centimetre-level positioning at scale in automotive and robotics applications.

In testing at Thetford Forest, a standard GNSS reference environment for dense-foliage performance, Precise+ delivered 80 cm accuracy at the 99th percentile. State-of-the-art receivers produced errors exceeding three metres in the same conditions. The results are receiver-level only, meaning the gains compound with whatever sensor fusion, RTK, or PPP corrections an integrator applies on top.

“RTK and PPP deliver centimetre accuracy in open sky but degrade sharply where signals are disrupted by tree cover, buildings or multipath,” said Scott Pomerantz, CEO of FocalPoint Positioning. “This limits deployment to a narrow slice of the road network, not the environments people actually drive in.”

Precise+ targets automotive ADAS, automated driving, and V2X applications, and is applicable to any system requiring sustained high-precision GNSS outside open-sky conditions. FocalPoint says it is working with leading chipset manufacturers on commercialization.

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The single-feed stacked patch design supports simultaneous L1 and L5 reception without the complexity of multi-feed architectures. Dual-band operation reduces multipath interference, improving positioning reliability in complex RF environments. The antenna achieves peak gain of up to 1.5 dBi, approximately 50 percent efficiency across both bands, and an axial ratio of around 4 dB, providing stable right-hand circular polarization and consistent positioning performance. It is optimized for GPS, Galileo, GLONASS, and BeiDou.

Two variants are available. The passive GVLB208.A uses a pin-mount configuration compatible with standard PCB designs, with optimal performance on a 70 x 70 mm ground plane. The active AGVLB208.A adds onboard electronics and filtering and ships with a 1.13 mm micro-coax cable and I-PEX MHF I connector for direct integration with current multiband GNSS modules.

Target applications include UAVs, autonomous delivery robots, telematics, and fleet management — use cases where high-precision positioning is required but form factor constraints limit antenna options.

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The P8 sits at the top of the G5 tier structure, distinguished by Septentrio’s AIM+ Ultimate interference mitigation — a step above the AIM+ Premium protection on the P6 released at XPONENTIAL earlier this month. Beyond interference rejection, the module delivers situational awareness data combining spoofing indicators with power and frequency information that operators can use to help localize jamming sources.

The design also emphasizes integrity: the module is built to ensure truthful positioning and reporting, with automatic sensor switching during GNSS disruptions in heavily compromised environments. Secure communication with input and output authentication guards against unauthorized access and data interception.

The P8 shares the G5 family’s 23 x 16 mm footprint and 2.2-gram weight. It supports open-source autopilots PX4 and ArduPilot for drone integration, and an evaluation kit with direct autopilot connections is available through Septentrio’s RxTools interface. Septentrio began volume shipments of the broader G5 line last October.

Septentrio, part of Hexagon, is demonstrating the mosaic-G5 P8 at SOF Week in Tampa this week, booth 609.

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The release encompasses 72 products drawn from 15 GNSS RO receivers or receiver constellations, processed at four independent processing centers. Missions represented include COSMIC, CHAMP, GRACE, METOP, TanDEM-X, TerraSAR-X, and KOMPSAT, alongside commercial data providers Spire and PlanetIQ. Data from EUMETSAT’s ROM SAF, JPL, and UCAR are also included.

The standardization effort addresses a longstanding friction point in RO data use: independent retrieval and processing centers have historically produced outputs with differing variable sets, complicating multi-source analysis. The new version 2.0 products give those datasets a common structure across Level 1b through Level 2b processing — from calibrated phase and orbit data through high-resolution bending angle and refractivity profiles to temperature, pressure, and humidity retrievals.

Version 1.1 of the products remains available through the AWS Registry of Open Data. The algorithm was developed with support from NASA’s ACCESS 2019 program and the NASA Supplements for Open Science Support. Full documentation is available via the README and Algorithm Theoretical Basis Document on NASA Earthdata.

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The deal adds 44 antennas to Intuitive Machines’ space-to-ground network and brings in Goonhilly’s Lunar and Deep Space Communications, Commercial Satcom, and Defense and Security divisions.

The acquisition is aimed squarely at building an integrated, end-to-end network for communications, data transport, and position, navigation, and timing services across low Earth orbit, lunar, and cislunar environments. Goonhilly’s assets include the 32-meter GHY6 antenna and the cryogenically cooled 30-meter GHY3, with multiband support across X-, S-, and Ka-/Ku-band frequencies. Its strategic location in Cornwall expands Earth-viewing arc coverage for lunar and deep-space contact windows.

“Customers have been clear that they want a single, integrated, and resilient solution for their communications and PNT needs as they accelerate missions at an unprecedented pace,” said Steve Altemus, co-founder and CEO of Intuitive Machines.

The transaction follows Intuitive Machines’ January acquisition of Lanteris Space Systems (formerly Maxar Space Systems) for approximately $800 million and a subsequent $175 million strategic equity investment. The company reported record Q1 2026 revenue and raised its full-year guidance to $900 million–$1 billion, with a backlog of $1.1 billion. Intuitive Machines was also recently selected for the Air Force’s $1.8 billion Andromeda contract vehicle for space domain awareness.

Goonhilly will retain its UK identity and Cornwall base as a wholly owned subsidiary. The transaction requires approval under the UK National Security and Investment Act 2021 and from the U.S. Federal Communications Commission, with close expected in Q3 2026.

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