We asked our Editorial Advisory Board (EAB) which emerging sectors are driving the most demand for advanced positioning and timing solutions right now?
“The defense sector needs an off-the-shelf GNSS module that is small, light and low power, yet also highly resilient — such as a military-grade location system — to satisfy the insatiable growth in drones. While this segment is about a tenth of the total commercial vehicle market, it is significant compared to the emerging autonomous driving segment, where the need for resilience is still trying to figure out the cost-benefit of mitigating intentional interference.”
“If I had to pick newly emergent sectors with the highest need for precise and continuous PNT, I would say the autonomous system operations sector and portion of the artificial intelligence (AI) sector. AI cannot provide spatially or temporally ‘intelligent’ support if it does not have access to precise positioning and timing information from outside itself. PNT sources do not depend on AI, but ‘autonomous’ AI must have reliable PNT.
“The primary driver is the broad adoption of autonomy and automation across industries such as construction, logistics, agriculture, infrastructure, defense, or even entertainment. Amplifying this demand is the proliferation of smaller and lighter UAVs, drones and robots. Where a single manned platform once required one navigation system, a drone swarm may require hundreds or thousands of units. It is the combination of these two forces, adopting autonomy and automation and multiplying platforms, that is driving demand growth.”
For many, the meaning of advanced positioning and timing solutions equates to solutions that provide higher accuracy and precision. For me, achieving an advanced PNT solution must require equal focus on the other PNT metrics — availability, integrity, continuity and coverage. Given the tumultuous state of the world these days, there is an emerging demand for solutions that enable resilient PNT in the defense sector, the commercial aviation and maritime sectors, in telecommunications and in power
Among the technical approaches being researched this year for GNSS/PNT protection, which do you consider most effective or promising?
Photo: Jules McNeff
“The simple answer is what I have been saying many times before. The most effective way to back up GPS/GNSS is to use the terrestrial technology available from eLoran. It is affordable, long-range, precise and essentially unjammable. However, it’s not what I would call ‘promising’ because that’s not what the government wants to hear. In fact, the government is in the process of dismantling the existing Loran infrastructure that could easily be recapitalized as autonomous eLoran stations. eLoran could provide robust nationwide timing and positioning preservation, including in the northern Pacific Ocean and Alaska, as well as across the Arctic, with Canada, to link up with our allies in the UK and Europe, who are also investing in eLoran. There is no real commercial market in the far north and there are no commercial systems proposed that can provide such coverage in those areas where we are facing challenges from Russia and China today and that will only increase into the future.”
—Jules McNeff
Allison Brown
“L-band jamming and spoofing is now prevalent in many parts of the world. It has now been confirmed that space-based jammers have been active, as well as conventional terrestrial jamming. Anti-jam solutions can only provide protection up to a certain jammer power level and are not a ‘silver bullet’ solution. Moreover, nulling of space-based jammers will also have the effect of nulling parts of the sky where GPS satellites are in view, degrading performance by reducing DOP. Alternative PNT solutions that are not relying on L-band signals are the most effective solution for operations in highly contested, jammed or spoofed L-band environments.”
— Allison Brown
Mitch Narins
“I believe that both orbital and ground-based PNT systems, operating in tandem and integrated properly, are the ultimate solution for critical infrastructure applications, but to get there, ‘the budget-office-inspired problem’ of having to pick one and only one must be abandoned: prevention is usually cheaper than curation. Only after space-based and ground-based PNT designers, developers, regulators and users understand and welcome the essential nature of PNT source diversity will we actually achieve the resilient PNT capabilities that we all need.”
What urgent policy or industry actions are needed to protect and advance resilient PNT services amid spectrum sharing debates and GNSS regulation changes?
Jules McNeff, vice president, strategy & programs, Overlook Systems Technologies
In my article, “Is There a Silver Bullet for Resilient PNT?”, I addressed the confusion caused by the numerous and diverse industry initiatives now being offered. Industry is understandably motivated to provide resilient PNT capabilities, but each also wants the government to pick its solution and make policy decisions accordingly. Spectrum sharing decisions that favor a single service provider may harm others in a crowded space, and so are difficult or impractical, as we have seen with the decades of litigation associated with LightSquared/Ligado and the spectrum surrounding the GPS L1 frequency.
Not everyone can win that competition, and as I noted at the end of the article, “Unless our government accepts responsibility, there will be no PNT silver bullet for domestic CI. Experience shows that industry will not solve this problem alone.”
For years, I have advocated that U.S. PNT technology policy be managed and services acquired holistically as vital dual-use civil/military capabilities. For the civilian community, that means making sure the national leadership understands the reliance our domestic critical infrastructure (CI) has on constant access to precise PNT to maintain continuity of operations across all CI sectors in the face of well-known threats. The leadership must then decide whether that reliance deserves proactive attention by the government to ensure PNT continuity is not disrupted.
Several years ago, I suggested that significant regulatory changes were needed in how civil PNT services were handled throughout U.S. CI. Both the Departments of Homeland Security and Transportation were assigned responsibility in Presidential Directives for finding a GPS backup to PNT services in domestic CI. I won’t revisit that years-long debate (which is still unsolved), but I will revive the framework of the suggestion.
The DOT has overall responsibility for civil agency PNT matters, and DHS frequently cites lack of regulatory authority as a limitation on its ability to encourage compliance in the CI sectors for which it is responsible. Therefore, I suggested that the National Space-Based PNT Executive Committee consider regulatory changes to expand the definition of the Transportation CI Sector to include safe and uninterrupted transportation of all elements contributing to domestic critical infrastructure. In addition to current air, road, rail, and oil/gas pipeline transportation, add the interstate transport of information (Communications and IT), electrical energy (Power Grids), economic transactions (Finance), crops (Agriculture), and water, as well as domestic maritime services (U.S. Coast Guard) and possibly emergency response services in the case of large disasters.
In the spirit of the former Interstate Commerce Commission, which years ago was replaced by a DOT Surface Transportation Board (primarily concerned with freight rail), the DOT may then seek expansions to STB authorities and membership to address the PNT dependencies and vulnerabilities affecting those fundamentally transportation-oriented activities vital to the viability of all U.S. critical infrastructure sectors.
— Jules McNeff Overlook Systems Technologies
Miguel Amor, chief marketing officer, Hexagon’s Autonomy & Positioning Division
Regulatory authorities must quickly approve and protect RF spectrum allocated for new PNT capabilities, particularly for emerging low-Earth orbit (LEO) constellations. These systems offer clear advantages in signal strength, geometric diversity and resilience against jamming and spoofing. Without timely and well-defined spectrum authorization, along with strong adjacent-band protections, the deployment of GNSS receivers capable of supporting these constellations will be delayed.
On the industry side, LEO PNT developers must urgently finalize signal structures and release Interface Control Documents, enabling GNSS receiver manufacturers to begin implementation, validation and system integration.
— Miguel Amor Hexagon Positioning Intelligence
Mitch Narins, Strategic Synergies
Interesting and timely question. I’ve written quite a few pieces and papers on the need for resilient and robust PNT services. If I were to point to a single thing that has held the US (and many other countries in the world back (except for China) it is lack of strong mission-oriented, dedicated leadership. It has been said that the definition of a committee is an entity with four or more legs and no brain. It is time to designate a single entity and a single office and a single person as responsible for ensuring resilient PNT services to US critical infrastructure so as to maintain the safety and security and economic benefits these these sectors support. Some wise men once came up with the idea that a government must “provide for the common defense” and “support the general welfare.” Resilient PNT is essential to achieving both.
In addition to the lack of empowered, centralized PNT leadership, a key problem that has impeded progress towards resilient PNT is the lingering belief by many that given enough time and money and spectrum, GNSS-sole means is achievable and that all non-GNSS systems (affectionately called “Legacy PNT Systems”) can be discontinued. In fact, over the years budget justifications for GNSS systems have used discontinuance of ground-based systems as “a benefit” to balance out the costs of establishing, updating, and operating GNSS.
Engineering System Designer should never fall in love with their solutions. The mission, i.e., the needs of the customers must always remain their first concern. After many years, integrity was added to the list of PNT metrics; coverage has yet to be officially added. Yet, even today, there remains confusion regarding the availability metric and the associated risks. For GNSS systems, the risk of losing required PNT metrics should always be considered “1.0”, and therefore, for critical infrastructure users and providers, require effective and implementable contingency/continuity of operation plans. Loss of PNT performance (accuracy, availability, integrity, continuity, and coverage) the using GNSS can no longer be considered a “Black Swan” event.
— Mitch Narins Strategic Synergies
In the February 2025, Professor Washington Ochieng proposed the following question to the GPS World EAB.
When we discuss the security of GNSS/PNT systems, we nearly always focus on interference — i.e., meaconing, intrusion, jamming or spoofing. However, GNSS/PNT systems are embedded in systems of systems that also offer many other opportunities for cyberattacks. What should we do about it?
I have thought for some time about why this is an issue. This is an interesting question, and the answer should be straightforward – but it’s not. For whatever reason, it seems many in the “cyber community” believe they are different, somehow, and apart. This has been apparent to me in dealing with those in the cyber community regarding their PNT dependencies and vulnerabilities going back to the creation of USCYBERCOM as a separate combatant command within the DoD. Those in the cyber world seemingly do not see a need to recognize and account for the intersection of PNT and cyber as mutually integral parts of a broader Information Technology ecosystem. Yet, across that entire IT ecosystem, PNT is simultaneously an enabler and a product of IT functionality, as communications and data systems could not operate without it, and it is likewise vital to IT users in executing their diverse missions. Ultimately, interference effects, whether from jamming or spoofing in their various forms or from digital intrusions of one kind or another, disrupt vital elements of that IT ecosystem. Our national and economic security depend on the continuous, reliable, uncorrupted functioning of IT services enabled by and delivering PNT information. So, a straightforward but difficult to implement answer is that we need formal education programs to routinely inform the leaders of industry and government (and the public) of the ubiquitous, vital role of positioning and timing (what we call PNT) throughout all the systems-of-systems whose operation depends on the IT ecosystem – and how to tell if something is amiss.
Question: What are the main challenges facing GNSS/GPS-based autonomous solutions in terms of signal integrity, jamming and spoofing, and how are these being addressed?
Answer: Outside of the military, interference is the most common threat to GNSS, with the dominant source being cellular transmission harmonics. It is commonly addressed with out-of-band filters. Non-terrestrial networks (NTN), like Global Star uplink at 1.6 GHz, are gaining traction in more mobile and wearable devices to fill gaps in cellular availability. However, it can create coexistence issues for devices for concurrent L1 GNSS reception during NTN uplink.
In military cases, while intentional interference is effective, the increasing number of GNSS bands to cover requires more transmission power. Modernized GNSS signals with wider bandwidth signals require more jamming power, which risks detection by radiofrequency emission satellite systems such as Hawkeye 360. The frequency of spoofing events will likely continue to increase and spill over into civilian domains.
Thanks to the increasing number of test ranges being made available to commercial GNSS developers, anti-spoofing technology is making some gains, at least in the high-end systems used for autonomous GNSS.
Q: What are the most impactful use cases and sectors benefiting from recent advancements in autonomous solutions?
A: Ride sharing and transport are the likely winners in exploiting the cost savings of driverless systems with autonomous navigation. The past 15 years’ investments in the development of augmented navigation systems — mainly lidar and vision-based — are finally paying off as we see Waymo in service, and soon Uber and Tesla in commercial deployments. Still, these systems depend solely on GNSS as the absolute positioning system, used for navigation in non-urban environments, but also fallback in certain cases where the sensors are problematic, as well as system calibration.
Agriculture, being one of the first segments to exploit autonomous solutions, can still see incremental gains as GNSS corrections systems move RTK from local to regional, allowing some monthly service margin improvements. High-precision consumer products like robotic lawn mowers will be enabled with similar infrastructure. Data services are a key part of infrastructure, for communication as well as precision navigation enablement. Companies such as Swift Navigation, Point One Navigation and RxN networks are expanding their networks and competing with the likes of Trimble and Hexagon.
For our March 2025 issue, Professor Washington Ochieng proposed the following question to members of our editorial advisory board: When we discuss the security of GNSS/PNT systems, we nearly always focus on interference — i.e., meaconing, intrusion, jamming or spoofing. However, GNSS/PNT systems are embedded in systems of systems that also offer many other opportunities for cyberattacks. What should we do about it?
Miguel Armor
“As a GNSS receiver manufacturer and correction service provider, cyber attacks are a risk we must consider seriously that arises from our customers’ integration of our solutions into complex systems. At the receiver level, it is important to make risk assessments to identify vulnerabilities across all components and implement a robust, multi-layered security strategy that includes physical, network and software components. At the core, our strategy incorporates cybersecurity considerations into our product/service development processes. We utilize the ASPICE framework for our engineering processes and we layer into that process the ISO21434 standard to ensure that we take steps all along the development path to consider cybersecurity. We selected this standard from the automotive industry due to the connected car use case, which is now in the front of cybersecurity development. ISO21434 covers the entire development life cycle — from system, to hardware and software, to verification and validation — in a way that many other standards do not. As a correction service provider, we ensure our data streams are secure and reliable, maintaining the highest standards of accuracy and availability. We also use ISO27001 as an IT framework for our correction network infrastructure. Continuous monitoring and iterative improvements are crucial to maintaining a secure and resilient GNSS/PNT infrastructure. It is key also to prioritize redundancy and backup systems to ensure continuity and resilience, to develop a comprehensive incident response plan that allows for rapid action in case of a breach and to conduct regular employee training to promote cybersecurity awareness across all products and platforms.” – Miguel Amor, Hexagon Positioning Intelligence
Alison Brown
“Cyberattacks are a credible threat to all existing GNSS systems and certainly need to be taken into account when considering alternative resilient PNT solutions. In fact, Goal 3 of the recently released U.S. Department of Transportation PNT Strategic Plan identifies PNT cybersecurity as a critical element of PNT resilience. The National Institute of Standards and Technology (NIST) provided a report titled Foundational PNT Profile: Applying the Cybersecurity Framework for the Responsible Use of Positioning, Navigation, and Timing (PNT) Services. This cybersecurity framework was created for both users of PNT services to manage risks when using PNT signals or data, and for operators of alternative PNT services to leverage when providing PNT signals or services. It was created by applying the NIST Cybersecurity Framework (CSF) and provides approaches for cybersecurity for PNT by continuously monitoring for attacks (e.g., denial of service, jamming), false data, and other malicious behavior within the systems and across the PNT services, using data-driven methods and solutions. This Cybersecurity Framework should be routinely adopted by both users and providers of PNT services.” – Alison Brown, NAVSYS Corp.
GPS vulnerabilities have been widely reported in the press. What steps have been taken to back up GPS use in U.S. critical infrastructure?
Jules McNeff
“President Biden on April 30 issued a National Security Memorandum on Critical Infrastructure Security and Resilience. GPS plays a vital role in the operation of critical infrastructure, and some sectors are considering their own backups. Other than conducting studies and meetings to admire the problem, the federal government has done virtually nothing to provide a comprehensive answer. In fact, the government is now dismantling the Loran system, though enhanced Loran (eLoran) is a viable and affordable GPS backup, specifically recommended for use by prior U.S. Department of Defense and U.S. Department of Homeland Security Deputy Secretaries. Given the vital role PNT and GPS play, it’s a mystery why such a viable solution is simply ignored.”
— Jules McNeff Overlook System Technologies
Will GPS remain the Gold Standard of space-based PNT services for the foreseeable future?
“GPS led the emergence and growth of a global space-based PNT service enterprise and has been the Gold Standard since its inception. The U.S. Department of Defense and Air Force (now Space Force) have maintained that standard through stable, transparent, and consistent policies and continuous performance improvements for the services it provides to all users. Now, in the face of foreign competition, hostile threats, budgetary pressures, reorganizations and management fragmentation, dilution of corporate memory, and inconsistent leadership support, those policy and performance foundations are in danger of eroding. The outcome for GPS and its future in the global PNT Enterprise is purely in the hands of our federal leadership today.”
How can commercial space help bridge the GPS vulnerability gap by providing alternative PNT services?
“With the proliferation of commercial SATCOM services being launched to provide global broadband services, there is an opportunity to leverage these capabilities to also augment positioning, navigation and timing (PNT). The Defense Science Board has been directed to consider this and is evaluating how these commercial alternatives, such as PNT signals-as-a-service, could supplement GPS if technical and logistical challenges could be overcome.
With the recent announcement of Iridium buying out Satelles for $115M and the apparent interest in the U.S. Department of Defense (DOD) to consider using commercial alternatives to provide backup PNT, this is likely to spur other innovations in this space and bring more players (and investors) to the market. This has the potential to significantly increase PNT resilience around the world by enabling the use of existing SATCOM services, with a wide diversity of spectrum allocations separated from GPS, allowing operation
in a GPS-denied environment.
Deployment also can be accelerated by leveraging commercial manufacturers of SATCOM equipment who can rapidly release commercial products with alternative embedded PNT capability that can provide aiding data through the Modular Open Systems Approach (MOSA) standards already developed for A-PNT devices in the DOD acquisition process.
The major barrier to adoption of these services, however, could be the anemic funding being provided for adoption of commercial space services to Space Systems Command’s new Commercial Space Office (COMSO).”
OCX is more than seven years behind schedule. What are the consequences?
Greg Turetzky
“It’s more consequential than most people realize. The first and most impactful consequence is the limitation of the GPS constellation to
32 satellites. There are more healthy satellites in the sky and, more importantly, Block III satellites sitting in the barn. These additional satellites and their modernized signals would improve navigation globally with improved accuracy and resilience. Additionally, without OCX the L5 signals are labeled ‘unhealthy’ and therefore the constellation is labeled ‘pre-operational.’ Without OCX, L5 cannot reach initial operational capability (IOC), which prevents certain market segments from being able to officially use them. GPS will remain in third place if the delay continues.”
— Greg Turetzky Consultant
Michael Swiek
“OCX seems more than seven years behind when you consider that we have been hearing about it as a concept and then a proposal for years before it became an actual program. In the Hope and Crosby movie, “The Road to Rio,” Jerry Colonna leads a cavalry charge to rescue the heroine across several brief scenes. He never arrives, and the heroine is saved by other means. Colonna then proclaims, ‘Well, we didn’t make it, but we sure added some excitement!’ While waiting for the heroic arrival of OCX, might the evolution of technology, and regular updates to the current system, already provide some of the improvements promised by OCX? The OCS is already upgraded to accommodate Contingency Operations for GPS III satellites, M-Code early use and incorporated cyber security protections. Is it, maybe, time to just move beyond OCX and start anew with today’s context and assessment of future needs?”
Should GPS have a satellite-based high-accuracy service, like Galileo’s and BeiDou’s? What would it take to build it?
Bernard Gruber
“No. As Peter Lynch once said, ‘Know what you own, and know why you own it.’ Although this sage advice was for individuals buying equities, I would offer the same for GPS investing in or ‘guaranteeing’ high-accuracy service. Myriad differential GPS solutions currently exist, next generation atomic clocks are in orbit now, internet-based corrections are available. Evolution will improve accuracy, and techniques for higher accuracy will develop when they are needed by the market. I would rather see investment continue in Alt Nav and compatible GPS solutions. As for Galileo and BeiDou authentication plans, I may provide a different answer.” — Bernard Gruber Northrop Grumman
Jules McNeff
“What’s in a name? For most people, GPS already provides a high-accuracy service. Depending on how one uses its signals, you can already track the movement of tectonic plates and changes in Earth reference frames — that’s pretty high accuracy. There are always those who want more, but it’s unreasonable to expect GPS to be the only source, given performance and resilience gains with positioning, navigation, and timing (PNT) augmentations and complements along with GPS basic services. The GPS providers need to focus on Job One, a robust set of GPS services for all its users, and not have that mission complicated further.” — Jules McNeff Overlook Systems Technologies
What are the key challenges and promising trends for GNSS/PNT over the next three to five years?
Bernard Gruber
“In 2023, the GPS program celebrated its 50th anniversary. It has had untold positive impacts on the world. I strongly believe this trend will continue through GNSS and complementary PNT systems for the next 50 years! That said, continuing challenges faced in the era of great power competition — specifically, to disrupt, deny, and destroy PNT capabilities — pose a clear and present danger. Ingenuity, competition, and strong coalitions will drive how we think and how we utilize our incredible resources – human and system – to persevere.
Unfortunately, challenges will always exist. Since the beginning, the GNSS community has had to deal with jamming threats, such as pervasive black market ‘cigarette lighter’ jammers, militarily sophisticated ones, or brute force high powered systems. This challenge will not go away. The burgeoning of artificial intelligence and machine-to-machine computations offers an opportunity and poses a threat: as commercial and government entities embrace these technologies, they exponentially increase the need to adapt.
Several promising trends will continue. Through the hard work of countless governmental organizations supporting the National Coordination Office, periodicals such as GPS World, academic papers, conferences and symposiums, marketing and communications, the public is now aware of how vital GNSS and PNT systems are. Second, buyers, operators, and users will demand that robustness be built into systems by anticipating needs such as increased cybersecurity, assured access, and tiered defense schema.
Third, innovative technical trends will drive increased processing power, cybersecurity/encryption toughness, signal diversity, adaptive antennas, and network augmentations, while an ever-increasing focus on model-based engineering and digital twins will allow us to field and learn faster. Additionally, as signal diversity grows, the opportunity for software-defined radios that utilize authenticated and available signals while ignoring others automatically will mature; programs such as the NTS-3 demonstration will at minimum force the decision of how we adapt.”
— Bernard Gruber Northrop Grumman
Jules McNeff
“Trends have emerged and evolved over the last three decades — since GPS became operational — that addressed earlier challenges and yet have created new, and possibly more daunting, ones. Early issues with awareness and acceptance of the need for continuous, precise positioning, navigation and timing (PNT) have been overcome, and the markets and governments have responded with a proliferation of PNT services — both space-based and other.
I’ll leave the market trends and opportunities to our industry colleagues and focus more closely on some remaining challenges that are particularly vexing to me. That requires stepping outside the comfortable GNSS/PNT-as-a-technology engineering and science bubble full of topics for collegial international cooperation. Instead, one must look at GNSS/PNT as an incredibly valuable tool for public safety, political and economic advantage, and military dominance, all separate, but closely interrelated and so as a tool to be protected. Other nations, some unfriendly to the United States, recognize the political/economic reality and are deploying PNT services to compete with GPS and erode international public confidence.
The U.S. government appears complacent and naively unwilling to accept that changes are necessary in its approach to international economic competition in PNT technology over the immediate future. Similarly, in the public safety arena, most of U.S. critical infrastructure (CI), an area of federal government responsibility, is well-known to be vitally dependent on GPS to function. However, the government agencies responsible for CI have been beyond reluctant to implement needed resilience measures, specifically regarding the terrestrial enhanced Loran (eLoran) system, which would provide substantial resilience if GPS service were lost or disrupted. This is despite multiple requests over the last decade from Congress and the National PNT Advisory Board to recapitalize eLoran.
At the same time, friendly and hostile foreign nations invest in their own eLoran systems to bolster PNT resilience within their sovereign territories. Knowing this, the United States cannot be happy with a situation that threatens economic and national security, yet it persists. Finally, and also important to public safety, we need to get serious about how PNT positions (geoaddresses) are reported to the public – important for economic purposes and specifically for incident/accident location and emergency response operations of all kinds. Continuing reliance on lat/lon as a default or on unique proprietary methods is both ineffective and dangerous given the ready availability of the U.S. National Grid as a public resource, as identified in the U.S. Federal Radionavigation Plan. As with eLoran above, the public safety challenge is to save lives and livelihoods and not allow them to remain at risk.
— Jules McNeff Overlook Systems Technologies
Jean-Marie Sleewaegen
“Recent years have seen a spectacular boost in the number of global navigation satellite systems (GNSS) satellites and signals. The launch pace has now slowed down, which does not mean the end of GNSS innovation. On the contrary, now comes the time to exploit and get the best out of all these new signals and services.
One of the first benefits of signal diversity is improved resilience: the more signals, the more fallback options in case of jamming or spoofing. Designing the optimal blend of all the constellations and signals into a precise and resilient PNT solution is and will remain a major innovation challenge in the industry. The recent introduction of Galileo OSNMA and the announcement of authentication services by other systems will play a key role in this evolution.
Having many types of signals also means that there are many ways of dealing with them. This is particularly visible in the current PPP-RTK offerings. Various service providers use different correction formats as well as protocols and this complexity is still too exposed to users. A key challenge will be the standardization and consolidation of the correction environment in a multi-constellation and multi-signal context. At the receiver side, this involves evolving from a vendor-specific to a correction-agnostic approach.
In the next few years, the focus will also expand beyond classical GNSS, with the announcement of the first low-Earth orbit (LEO) LEO PNT constellations, promising improved precision, resilience, and security compared to traditional medium-Earth-orbit (MEO) GNSS. The promises and challenges of LEO PNT constellations and their interoperability with GNSS will undoubtedly foster major innovations in the PNT industry.”
— Jean-Marie Sleewaegen Septentrio
Michael Swiek
“A basic question for the next three to five years is how will we be receiving PNT, or P, N, and/or T individually or in combination and from where? We have become accustomed to receiving reliable PNT from government-operated MEO satellite constellations. However, new options appear to provide PNT or P, N, or T from LEO constellations, terrestrial beacons, etc., from both government and private sector providers. These options can help address vulnerabilities in traditional GNSS services and provide options for new applications. The question becomes one of coordination and integration of diverse solutions. The challenge is managing the technical, market and regulatory elements while not undermining existing stable infrastructure or future innovation.”
What is the most promising innovation in satellite navigation being introduced by BDS, Galileo, QZSS, or NavIC?
“Two things are having an immediate impact: authentication methods, such as Galileo’s Open Service-Navigation Message Authentication (OS-NMA), and the proliferation of correction services for high accuracy. Navigation message authentication offers a practical, easy-to-implement defense against several (though not all) types of spoofing attacks. QZSS and NavIC offer this too. And though paid correction services have been available for some time, Galileo’s High Accuracy Service (HAS) will bring it into the mainstream. Sometimes innovation is just applying simple techniques in a useful, efficient manner.”
For critical infrastructure, how good a remedy are multi-constellation receivers to GNSS vulnerability?
“Multi-constellation receivers do not do much to combat jamming and spoofing; they only detect failures in a constellation itself through comparison. Since they all are open standards, a good spoofer can fake all the systems simultaneously. Multi-frequency receivers are a bit more resistant to jamming, since one must jam multiple bands, but since all the bands are relatively close, the barrier is not high. To be truly resilient, you need diverse, redundant PNT sensors — IMUs, CRPAs, strong signals of opportunity, lidars, etc. — in addition to GNSS receivers.”
“Regarding augmentation services such as Galileo HAS, at what accuracy level should public services end and private ones begin?”
Michael Swiek
“This reminds me of the questions that arose many years ago over whether the U.S. Coast Guard differential correction service (DGPS) would unfairly compete with commercially provided augmentations. I don’t know whether there is a single rigid number that fairly separates publicly provided augmentations from commercially provided ones, or if such a number could be set for all time. It would probably need to be flexible, and evolve over time as needs change and technological improvements come to pass. In the end, the public-provided service should be at a reasonable minimum level to address an identifiable broad public need — such as safety of life requirements — but not so fine as to undercut finer levels of accuracy for which there is a market of users willing to pay for such services from the private sector. This could ensure a responsible service provision for the public good, as well as a healthy competitive environment for commercial technological development.”
