Alternative. Backup. Complementary. These words describe the global efforts to find technologies capable of fulfilling critical infrastructure requirements for positioning, navigation and timing (PNT) in the absence, degradation or disruption of GNSS services. This search has been ongoing and continues to evolve. Here, we provide a historical look back at some of the efforts in the U.S. and Europe, a snapshot of the current PNT environment and how it has influenced more recent developments in the search for resilient PNT solutions, and a glimpse into what may lie ahead in that quest.

The U.S. Leads the Charge 

For years, the U.S. has been sounding the clarion call to protect, toughen and augment PNT.

The 2021 analysis prepared by the Volpe National Transportation Systems Center under the direction of the U.S. Department of Transportation (DOT) was one of the early studies charged to identify viable backups or complements to GPS. 

The Volpe Report evaluated the effectiveness of 11 different technologies from various companies and organizations based on several performance characteristics (e.g., resilience, accuracy, coverage and deployment feasibility) using 14 Measures of Effectiveness (MoE), across various scenarios. 

Specifically, the five timing scenarios assessed vendor systems based on four attributes: 72-Hour Bench Static Timing, Static Outdoor Timing, Static Indoor Timing, Static Basement Timing, and eLORAN Reference Station Offset. DOT also developed four positioning scenarios to assess vendor systems based on these five attributes: Dynamic Outdoor Positioning with Holds, 3D Positioning, Static Outdoor Positioning, and Static Indoor Positioning.

Volpe, however, also concluded no single alternative technology can fully replace GPS or meet all PNT requirements across its four identified critical infrastructure sectors (Transportation, Telecommunications, Energy and Space Operations). Instead, it recommended the use of a diverse portfolio of complementary technologies to enhance the nation’s critical infrastructure. It also emphasized the importance of continued research and development, the need for public-private partnerships to explore and deploy effective PNT solutions and the necessity of federal guidance and coordination to ensure the interoperability and security of alternative PNT (A-PNT) systems.

Europe Gets into Alt-PNT Game 

It has been three years since the Volpe Report was published, and new technologies have emerged that were not tested. Hence, the European Commission (EC) Joint Research Centre (JRC) in Ispra, Italy, launched its own testing campaign for A-PNT, using a Call for Tender from the Directorate General for Defence Industry and Space (DEFIS). The resultant report presented the findings from this latest and extremely comprehensive European test campaign (“DEFIS Report,” officially titled “Assessing Alternative Positioning, Navigation and Timing Technologies”).

Six companies were awarded EC contracts for the test campaign: OPNT BV, Seven Solutions SL, Satelles Inc., GMV Aerospace and Defence, Locata and NextNav. The JRC used several key performance indicators (KPIs) and related performance characteristics: robustness to interference (including for GNSS frequencies, weak RF, strong RF), encryption-readiness (including for data, signal) and scalability to local, regional or continental areas.

Like the Volpe Report before it, the DEFIS Report does not specify a single “winner” among the technologies tested. Both NextNav and Satelles tech again performed well in several tests. However, studying performance Tables 1 and 2 (as published in the final JRC DEFIS Report), it’s clear Locata’s new technology appears to have been the top performer in this study. Locata was the only technology, amongst all of the PNT candidates, that delivered exemplary performance in all tested environment scenarios, and also across all tested resilience, accuracy, and deployment parameters.

Locata is a terrestrially based technology that offers high-precision positioning and timing. It uses a network of proprietary ground-based transmitters, known as LocataLites, which emit signals that a Locata receiver can use to calculate its position with high accuracy. The Locata network is novel in that its transmitters can maintain sub-nanosecond synchronization without any dependence on GPS, satellites, external corrections, or the atomic clocks relied upon by all other tested systems. This unique new capability was clearly demonstrated during the JRC tests and is documented in the final DEFIS Report. Locata specifically designed this technology to work in areas where GPS and other GNSS signals are unreliable or unavailable.

In the JRC tests, Locata’s tech displayed significant resilience, the ability to maintain operational capability in the face of challenges such as signal interference, jamming or environmental obstacles. Locata tests, conducted in both an industrial test facility in Düsseldorf, Germany, and a “multipath-rich” indoor space at the JRC facility in Ispra, assessed the positioning accuracy of Locata technology against various challenges, including those that affect resilience. The technology’s performance in these diverse environments suggests a high level of resilience, particularly in overcoming signal multipath issues common in urban and indoor environments.

Accuracy, a critical measure for any PNT technology, indicates a system’s ability to provide precise location and timing information. JRC engineers tested Locata systems to measure the precise time transfer capability and positioning accuracy. The tests included a local area component within the JRC facility and a wide area component extending outside the premises, using an outdoor “timing backbone” to also synchronize an indoor positioning network. The specific numerical results of these tests indicate a focus on validating the accuracy of Locata’s technology under different conditions.

The JRC tests also covered the practical aspects of deploying the technology on a wide scale, including infrastructure requirements, scalability and integration with existing systems. For the JRC demonstrations, Locata used its technology at a fully automated port machinery manufacturing and testing facility. The autonomous machinery at the site was used to demonstrate Locata’s centimeter-level performance in environments requiring high precision and reliability, plus its ability to integrate into complex industrial applications. Additionally, the demonstration of UTC time transfer to an indoor Locata Rover suggests the technology’s capability to integrate with global time standards, an important factor for deployment feasibility. The report confirmed that Locata’s ground-based networks provide non-GPS based, centimeter-level positioning accuracy in areas where GPS doesn’t work. 

What did we learn from the Volpe and DEFIS Reports? Despite originating from different regions at different times, they share several commonalities in their findings regarding A-PNT. 

Commonalities and Learnings 

The commonalities of both Volpe and DEFIS reflect a global consensus on the need for resilient PNT solutions that can complement or serve as backups to GNSS. At a high level, both reports also underscore the vulnerabilities of GNSS, including susceptibility to jamming, spoofing and signal degradation in certain environments. This shared concern highlights the critical need for A-PNT solutions to ensure continuity of services for critical infrastructure and national security.

Resilience and accuracy emerged as key performance characteristics in both reports, especially in transportation and telecommunications. Both reports evaluated technologies for their ability to provide reliable and precise PNT information, even in challenging conditions where GNSS signals are compromised. 

From these demonstrations, Locata, NextNav and Satelles seemed to be the top contenders. At the same time, both reports concluded that no single A-PNT technology can fully replace GNSS across all applications and sectors. Instead, they advocated for a diverse portfolio of technologies in a system-of-systems integration to serve different needs and environments in a layered approach. 

The two reports also converged on the needs for further R&D, supportive public-private partnerships and policy frameworks to enhance the resilience of PNT services worldwide. 

With regard to the ongoing need for R&D, they focused on the requirement to enhance the performance, scalability and cost-effectiveness of A-PNT technologies and emphasized the importance of innovation and testing to identify viable solutions that can be deployed at scale. This specific point seems to be at the core of the U.S. Department of Transport Critical National Infrastructure tests. 

Finally, they agreed that on the policy front, considerations for interoperability, standardization and security will ensure these technologies can be effectively implemented within existing infrastructure.

Since the publication of the DEFIS and Volpe Reports, several global events have highlighted the vulnerabilities of relying solely on GNSS and have validated the need for real solutions now.

The Evolving Threat Picture 

In the past few years, the world has witnessed a ramp up in cybersecurity threats, geopolitical tensions, natural disasters, space weather events and climate change as well as technological advancements that come with their own new vulnerabilities. All of these underscore the increasing importance of resilient PNT systems and robust alternative solutions.

Cybersecurity threats, including more sophisticated cyber-attacks on critical infrastructure, have risen in number. Attacks on energy grids, transportation networks and government databases have shown how vulnerabilities in digital and communication networks can be exploited. For example, the energy grid, both in the U.S. and globally, faces numerous virtual (cyber) weak spots that can lead to disruptions in power supply and everyday life unless alternative solutions can shore them up.

Escalating geopolitical tensions involving major powers have led to additional concerns over the security of satellite navigation systems. Instances of GPS signal jamming and spoofing in conflict zones, such as Russia-Ukraine, have extended to nearby regions.

Add to this the increasing frequency and severity of natural disasters, driven by climate change, which pose significant risks to GNSS infrastructure. Hurricanes, wildfires and earthquakes have been known to damage satellite ground stations and other critical infrastructure. A-PNT technologies can ensure continuous operations during and after such events.

Significant space weather events, such as solar flares and geomagnetic storms, have the potential to disrupt satellite operations. If a strong solar flare interferes with satellite communications, this could lead to reduced accuracy or a complete loss of positioning and timing data. This risk underlines the importance of having terrestrial and non-satellite-based systems as viable PNT alternatives.

Finally, technology continues to advance and with it, new vulnerabilities have emerged. The expansion of 5G networks and the Internet of Things (IoT) increases our dependency on precise and reliable timing, predominantly provided today by GNSS. Any disruption in GNSS services could have cascading effects on everything from urban transportation to critical health care services. This interconnectedness highlights the need for diversified PNT solutions to provide independent backup in the event of GNSS failures.

These events collectively illustrate the growing imperative for countries and industries to invest in and develop resilient PNT systems that can ensure continuity and reliability of critical services in the face of diverse and evolving threats. As the need for robust A-PNT solutions has become more critical than ever to safeguard national security, economic stability and public safety, other countries have jumped on the A-PNT bandwagon—notable among these, the United Kingdom (UK).

The UK Launched Its Own Initiative

In response to the growing recognition of the vulnerabilities faced by space-based PNT assets, particularly arising from nearby geopolitical tensions, the UK launched a comprehensive strategy to enhance the resilience and innovation of its PNT services.

Key components of the UK’s PNT strategy included: development of a cross-government crisis plan to ensure immediate short-term preparedness for scenarios where services become unavailable; creation of a National Timing Centre to provide resilient, terrestrial, sovereign and high-quality timing services across the UK; a PNT Growth Policy emphasizing R&D programs, standards and testing activities across various sectors; and a Contextual Complementary PNT (CPNT) Framework to dovetail off work from the JRC and DOT.

In support of this strategy, the UK Research and Innovation Council unveiled a Strategic Priorities Fund. The UK National Timing Centre currently spearheads this 5-year £36 million initiative dedicated to ensuring reliable Time and Frequency services across the UK. It has three main objectives: establish a Resilient Enhanced Time Scale Infrastructure; financial support to the UK industry through Innovate UK; and offering specialized training programs for experts, postgraduates and apprentices.

Specifically, to enhance the nation’s timing resilience, the initiative plans to broaden the network of sites generating time by providing atomic clock backups to ensure users have access to UTC(k) traceable time (think: network of resilient, distributed atomic clocks throughout the UK). This Resilience Enhanced Time Service (RETS) infrastructure includes four sites designed to operate independently of GNSS. 

As the UK continues to ramp up its timing efforts, so too does the USDOT’s effort to develop and implement CPNT technologies.

DOT Ramped Up Its Search

Over the past year, in what can only be characterized as an intensification of effort, the USDOT issued both a Request for Information (RFI) and a subsequent Request for Quotes (RFQ).

The RFI clearly indicated the DOT primarily seeks high Technology Readiness Level (TRL) non-space-based alternatives that can offer accuracy, integrity and resilience under adverse GNSS conditions. It specified stringent requirements for the tech it seeks, including accuracy and integrity in the face of signal disruptions, reliability to withstand a variety of signal threats, and stringent security practices consistent with national cybersecurity frameworks.

In our recent interview with the Office of the Assistant Secretary for Research (DOT/OST-R) Director for the Office of Positioning, Navigation and Timing & Spectrum Management Karen Van Dyke on the follow-on RFQ, she characterized DOT’s effort as “a two-pronged approach” focused on bolstering GPS as well as finding “gap fillers,” to step up if GPS becomes unavailable.

At the Assured PNT Summit Conference in Washington D.C. in late May, Van Dyke announced that the DOT hoped to award contracts to the CPNT candidates selected by the U.S. Government for Critical National Infrastructure testing sometime in June, and they did. 

No One Size Fits All 

One thing is for sure, whether in the U.S., EU or UK, there will be no one size fits all solution for A-PNT | CPNT because the relevant critical infrastructure sectors each have their own specific operational requirements and challenges that make certain A-PNT technologies more suitable than others. What we’ve seen, based on the demonstrations so far, is some tech works for some applications and arguably, some of that tech could work across all.

Together, these technologies could provide the necessary resilience, accuracy and security to support the critical infrastructure sectors identified in the Volpe and DEFIS Reports. In the meantime, all we can do is continue to wait and see what developments will continue to occur both in the U.S. and across the pond, in the search for A-PNT and CPNT solutions that will protect our security, economy and daily lives.

The post The ABCs of PNT appeared first on Inside GNSS - Global Navigation Satellite Systems Engineering, Policy, and Design.

Positioning, Navigation, and Timing (PNT)-related solutions stood out among the many other cutting-edge space technologies showcased by over 230 innovators, reaching across space agencies, commercial enterprises, military entities, governmental bodies, research and development institutions, educational establishments and entrepreneurial ventures. Here’s a review of some of the more distinctive PNT efforts, live from the Space Symposium expo hall floor.

Spaceport America – AeroVironment Sunglider

Located on 18,000 nautical miles of trust land in Las Cruces, New Mexico, within the envelope of the Space Valley Coalition, a pioneering partnership between Spaceport America and AeroVironment pushes the boundaries of PNT solutions. 

At an elevation of 4600 feet above Mean Sea Level (MSL), Spaceport America’s remote location, strategically chosen for its low nearby population, reduces risk and ensures uninterrupted experimentation. As it stands poised for the orbital launches of tomorrow, (anticipated within the next decade) it has become a current hub for suborbital ventures like Virgin Galactic’s space tourism endeavors, meteorological sounding and stellar observation as well as for unobstructed flight patterns. 

The latter provides the backdrop for innovative ventures like AeroVironment’s solar-powered High Altitude Pseudo-Satellite (HAPS) Sunglider, a joint venture with Japanese telecommunications company SoftBank. The Sunglider spans 262 feet across, shrouded in solar panels to harness the sun’s energy to power its remarkable capabilities. With a payload capacity of 150 lbs and a steady supply of 1500 watts, the Sunglider aims to redefine the possibilities of PNT solutions from an altitude of 60,000 to 80,000 feet.

Designed to loiter for up to six months at a time, the Sunglider can endure extreme conditions, including temperatures as low as minus 50 degrees Celsius in the stratosphere. Its mission encompasses not only PNT advancements but also facilitates 5G, marking a convergence of cutting-edge technologies.

According to Spaceport America Executive Director Scott McLaughlin, AeroVironment prepares to resume flights in May to test the Sunglider’s nocturnal descent to 60,000 feet powered solely by stored solar energy to prove its autonomy and adaptability. 

The Sunglider may play a pivotal asset in safeguarding critical PNT infrastructure by providing a backup PNT for GPS to support command and control (C2) and intelligence as well as  surveillance and reconnaissance (ISR) capabilities for the Department of Defense (DOD), among other stakeholders. As such, Spaceport America’s collaboration with AeroVironment on the unique Sunglider craft exemplifies innovation in PNT solutions. 

Safran – Skydel GNSS Simulation Software

Safran, the third-largest global aerospace company with a diversified portfolio encompassing air and spacecraft components, electronics, and defense solutions, also provides groundbreaking GNSS (Global Navigation Satellite System) Simulation software to a global clientele.

According to Marco Ventresca, Senior Sales Manager at Safran, Skydel, the company’s GNSS simulation software empowers customers to simulate and test their receivers and other equipment with unparalleled precision, covering a vast spectrum of GNSS signals and constellations including GPS, Galileo, and Xona’s PULSAR.

On the timing side, the simulator platforms integrate SecureSync technology, ensuring uninterrupted signal continuity even in the absence of GPS connectivity. Meanwhile, on the navigation front, Skydel facilitates comprehensive testing scenarios, from benchtop simulations to live sky testing, enabling clients to validate receiver performance in diverse environments.

What sets Safran apart, Ventresca explained, is the scalability and flexibility inherent in its software-defined architecture. Whether clients opt for turnkey solutions or prefer to integrate their own hardware, Safran’s software adapts seamlessly to meet their needs. This versatility extends from receiver testing to CRPA simulations and anechoic chamber systems, offering clients a holistic suite of solutions for their PNT requirements. The software’s compatibility with off-the-shelf GPUs  translates into reduced costs and enhanced flexibility and performance for clients. Finally, the software’s capability to realistically simulate jamming, spoofing and scintillation ensures that clients are equipped to confidently navigate real world challenges.

Pierre Desjardins, Business Development Manager at Saffran explained, “Our software saves companies both time and money. Traditional GNSS signals testing to ISO standards involves putting together costly fixed arrays, and driving around to receive the signals, to accumulate the required one million hours of testing for functional safety. Our software can provide this in a safe, remote environment from the comfort of one’s own computer screen.”

Safran’s commitment to innovation extends beyond commercial applications. Through initiatives like the Minerva academic partnership program, Safran nurtures collaborative research and development (R&D) with universities, providing its software for free to support students and professors.

In an era defined by evolving market demands, Safran’s GNSS Simulation software paves the way for a future of PNT precision and reliability that empowers industries worldwide.

Psionic – Navigation Doppler Lidar (PNDL) & SurePath System

Psionic, headquartered in Hampton, Virginia, produces the revolutionary Psionic Navigation Doppler Lidar (PNDL) technology. This innovative system leverages laser beams with minimal footprints to provide precise velocity and positioning data, eliminating clutter issues that plague conventional radar systems. This makes PNDL ideal for navigation in GPS-denied or challenging environments.

According to Diego Pierrottet, Chief Engineer at Psionic, the breakthrough behind their PNDL is precise altimetry and incredibly accurate velocity measurements powered by an all fiber-optic coherent LiDAR network. This technology delivers an unprecedented 1000-fold leap in sensitivity, outperforming traditional radar and revolutionizing navigation accuracy in the absence of GPS.

Among other highlights, the technology was demonstrated in the recent Odysseus lunar landing by NASA’s NDL in February 2024. The NDL’s compact design (about the size of a toaster) demonstrated remarkable data integrity using three 2 inch collection optics. In contrast the Mars Science Lab (MSL) used six 8 inch diameter radar antennas while landing over similar dynamics. The NDL also consumed significantly less power, while maintaining superior accuracy.

The PNDL’s versatility extends beyond aerospace applications. It appears poised to replace microwave altimeters with its superior precision, accuracy and immunity to interference. Psionic’s SurePath system is a derivative of the PNDL designed primarily for ground applications and has the potential to revolutionize high-precision navigation across a wide variety of vehicles, particularly in GPS-denied environments. This innovation aligns with emerging trends in autonomous navigation, particularly in ground vehicles, drones and air taxis, where SurePath could serve as a safeguard against GPS spoofing and aid in navigation in challenging terrains.

To this end, Psionic’s roadmap for commercializing the PNDL and SurePath includes miniaturization that will enable broader applications. The company aims to shrink the technology to a fraction of its current size, with aspirations to eventually be reduced to the size of smartphones by 2026, paving the way for transformative applications across various industries.

Parsons – Assured Positioning System (APS)

Parsons, a digitally enabled solutions provider focused on creating the future of the defense, intelligence and critical infrastructure markets, aims to redefine the boundaries of assured positioning through its newly released Assured Positioning System (APS).

A pioneering hardware and software configuration, the APS operates on a software-defined radio (SDR) platform. Parsons engaged in over two years of meticulous R&D to create a form factor optimized for operational effectiveness. Characterized by its low Size, Weight, and Power with Cost (SWaP-C) profile, according to Mike Hite, Business Development Lead for Parsons, APS earned the moniker “SDR peanut” for its compact yet potent design.

The heart of APS lies in its ability to harness commercial satellite radio frequency (RF) downlinks and convert them into actionable PNT information. With a global accuracy ranging between 30 to 40 meters (barring the polar regions), APS promises reliable positioning capabilities tailored for diverse operational environments.

Hite underscored the dual-use nature and versatility of APS and Parsons’ commitment to addressing the evolving needs of military and commercial sectors alike. In its current dismount configuration, soldiers can wear this tech. The company has near-term plans for vehicular installations, with a long-term goal of airborne vehicle integrations (think: drones). This phased approach, from dismounted to mounted configurations and ultimately to aerial platforms, reflects Parsons’ commitment to incremental innovation, epitomized by the mantra “crawl (dismount) – walk (ground) – run (flying).”

Stay tuned for more as Parsons continues to iterate on the transformative potential of APS.

L3Harris – Navigation Technology Satellite-3 (NTS-3)

Navigation Technology Satellite-3 (NTS-3), an advanced experimental satellite developed by L3Harris, stands poised to revolutionize assured PNT for the nation’s joint force.

The project began when L3Harris answered the call from the United States Air Force (USAF) for innovation to evolve PNT capabilities beyond the confines of GPS. To create the cutting-edge NTS-3 satellite, which will operate independently of GPS by using advanced and alternative waveforms, L3Harris integrated its technologies into the Northrop Grumman ESPAStar bus. 

This agile waveform platform will empower operators to develop and deploy new signals by allowing operators to simultaneously transmit Earth-coverage beams and multiple independently configurable regional beams. This will entail augmenting power levels and leveraging electronically steerable antennas to enhance resilience and allow for precise targeting of diverse areas of interest in denied environments, where traditional GPS signals may be obstructed or degraded. 

NTS-3 boasts several additional technological milestones, including the pioneering use of phased array antenna technology for space-based PNT missions. To tackle the challenges posed by transmitting and receiving PNT signals simultaneously, L3Harris collaborated closely with NASA’s Jet Propulsion Laboratory (JPL) to develop autonomous navigation capabilities that ensure operational continuity in adverse conditions.

According to Joe Rolli, Director of Business Development for PNT at L3Harris, another transformative aspect of the NTS-3 relates to its on-orbit reprogrammability and autonomous navigation, facilitated by state-of-the-art software-defined radio (SDR) technology.  Through the use of a fully reprogrammable in orbit Cion receiver, the satellite can utilize signals from multiple GNSS to enable such autonomous navigation, if necessary. This will ensure continuity even in scenarios where contact with ground control is lost due to interference. 

With a mission lifespan of 1 to 3 years, NTS-3 also epitomizes a faster, more agile approach to satellite deployment, poised to accelerate innovation and shape the future of PNT.

In collaboration with the Air Force Research Laboratory (AFRL), L3Harris has already meticulously validated NTS-3’s capabilities through a series of rigorous pre-launch tests, including range testing and thermal vacuum chamber testing. Range testing confirmed expected transmission performance and signal survivability of the innovative waveform in denied areas, 

Next up, AFRL and L3Harris have a suite of 100 experiments planned for the NTS-3’s orbital deployment later this year. The significance of these experiments cannot be overstated as they will undoubtedly inform the integration of novel technologies into future GPS satellites.

NTS-3 represents a paradigm shift in PNT capabilities, poised to deliver uninterrupted, assured navigation solutions tailored to the evolving needs of the nation’s defense forces through waveform operation, re-programmability and autonomy.

Shooting for the Stars

To be sure, Space Symposium featured other PNT tech not reviewed here. The organizations discussed here, however, represent some of those pushing the boundaries of what is possible for PNT in terms of resilience, augmentation, autonomy, testing, development and the overall future of the space-based PNT ecosystem. We applaud these, and all the companies, out there shooting for the stars to make PNT persistently available to everyone.

The post PNT Tech From the Floor of Space Symposium 2024 appeared first on Inside GNSS - Global Navigation Satellite Systems Engineering, Policy, and Design.

In this exclusive interview, Musawwir revealed the latest updates regarding the company’s Global Positioning System (GPS) III satellite project, including the evolution from GPS III to GPS IIIF, advancements in anti-jamming technologies, additional capabilities to bolster military navigation and security and a first responder search and rescue (SAR) capability.

A Brief Around the World…

The landscape of space has undergone significant transformation since the launch of the first GPS satellite in the 1970’s. It has evolved into an increasingly contested domain with a wide variety of emerging threats, ranging from competitive adversaries vying for superiority to space clutter to spoofing and jamming. To stay one step ahead of the ever-changing space environment, GPS has undergone a remarkable evolution since its inception, with each iteration representing significant advancements in technology and capabilities. 

Past GPS satellite generations include the Block IIA (2nd generation, “Advanced”), Block IIR (“Replenishment”), Block IIR-M (“Modernized”) and Block IIF (“Follow-on”). With each iteration, the GPS system had become more robust, reliable and capable of supporting a myriad of applications across various sectors.

Lockheed Martin’s GPS III and GPS IIIF (“Follow-on”) satellite project marks the third instantiation of the system.  Of the 31 total GPS satellites already in orbit, 6 of these are Lockheed’s Block III. The company is currently on contract to construct up to 20 of these next-generation GPS III/IIIF satellites, with additional contract options available to build up to 32 space vehicles. 

Next Gen GPS At the Ready

A response to the U.S. Space Force’s initiative to upgrade the current GPS satellite array, the GPS III process began with the award of contracts for 10 satellites, followed by plans for an additional 22 GPS IIIF satellites. 

According to Musawwir, Lockheed has completed the remaining 4 GPS III satellites (#s 7-10), which “remain at the ready for the Space Force to launch once they have the ability to do so.”

Space Vehicle 11 (SV11) marks the beginning of the GPS IIIF series, with satellites numbered 11 through 32 comprising this next phase of the GPS program. Lockheed Martin has already started manufacturing its IIIF satellites, with numbers 11 through 20 in active production. 

The assembly, testing and launch (ATLO) of these satellites takes place at Lockheed Martin’s state-of-the-art 40,000 square foot GPS processing facility in Waterton, Colorado. Integration plays a crucial role in the development of these GPS satellites. Lockheed Martin meticulously assembles all intricate systems and components to form fully functional satellites. After this, rigorous testing ensures the reliability and functionality of each satellite before launch. 

Given the “single line flow” nature of ATLO, Musawwir estimates 2026 for completion of the first GPS IIIF spacecraft. This will mark yet another significant milestone in the ongoing evolution of the GPS system, as these satellites represent the pinnacle of GPS technology, with enhanced performance to meet the evolving needs of users worldwide. This block contains cutting-edge technology and enhanced functionalities. Among these new capabilities, anti-jamming (A-J) features prominently.

RMP’ing Up

The new GPS III satellites will already have greater than 8x anti-jamming capabilities above other satellites in the GPS constellation. Musawwir emphasized the even-more powerful A-J capabilities integrated into the GPS IIIF satellites, called Regional Military Protection (RMP). Using RMP functionalities, satellites can operate in higher power modes which enables them to overcome or overpower jamming threats effectively.  RMP can provide up to 60x greater anti-jamming in theater to ensure U.S. and allied forces cannot be denied access to GPS in hostile environments. This is achieved through the refinement of radio frequency (RF) physics, by focusing the satellite’s beam into areas as small as 12 kilometers in diameter. 

The GPS IIIF mission takes this a step further. The tech onboard combines operational behaviors designed to provide additional power within certain frequency bands to counter jamming attempts. “It’s all about power distribution,” Musawwir explained. “We’re taking RMP to the next level.” 

The Search Is Over

Beyond A-J, Musawwir discussed various updates and enhancements incorporated into the GPS IIIF satellites. One notable addition, the SAR capability, enables the satellites to intercept distress calls and relay them back to Earth. Its antennas facilitate global communication, ensuring continuous access worldwide, with a growing presence in Medium Earth Orbit (MEO) to complement the GPS mission.

This can aid first responders in locating and rescuing individuals in emergency situations. This functionality is particularly crucial in maritime settings, where it is predominantly utilized. This feature, already on the Geostationary Operational Environmental Satellites – R Series (GOES-R), has proven instrumental in saving lives, contributing to over 400 total rescued facilitated by NOAA satellite SAR beacons over just a one-year period.

And Even More

In addition to RMP and SAR, the GPS III and IIIF satellites boast encrypted M-Code capabilities, ensuring secure and reliable access to GPS signals, particularly those in defense and security sectors. Currently, 25 vehicles come equipped with M-Code. This means users can rely on assured access to GPS signals even in contested environments. Once fully deployed, GPS III/IIIF will ensure that important capability is constellation wide.

Another crucial aspect of the GPS III/IIIF project, it includes its contribution to national security through the Nuclear Detonation Detection System (NDS). This system enhances the ability to detect nuclear radiation and pinpoint the location of nuclear blasts below Medium Earth Orbit (MEO) with precision. This can provide invaluable support for nuclear monitoring and response efforts.

The Sky Is Not the Limit

Lockheed Martin’s GPS III/IIIF satellite project represents a significant advancement in navigation and security technology. With enhanced A-J capabilities, SAR functionality, encrypted M-Code, and NDS integration, these satellites remain poised to redefine the standards for global positioning systems, by providing critical support to military operations, emergency response efforts and national security initiatives.

Looking ahead, Musawwir expressed enthusiasm for the continued evolution of the GPS program. “We’re excited to launch these next generation satellites in support of the Department of Defense,” he said. “GPS III, and the IIIF mission that will follow, will enable the warfighter to execute their missions…and to come home safe.”

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Now, Volpe has put out another relatively short-fuse formal Request for Quote (RFQ) to award multiple contracts to presumably some of the RFI-responsive companies.

In this exclusive interview with OST-R’s Director for the Office of Positioning, Navigation and Timing & Spectrum Management Karen Van Dyke, Inside GNSS gleans some insights into the why and how of the latest CPNT developments.

Why Now?

Jamming and spoofing has been a pervasive issue for the PNT community for years, but recent world events have ramped up these and other challenges to PNT (e.g., Russian cyberattacks on satellites and alleged plans to put nukes in space). If anything, the increasing and real nature of these threats have underscored the need to move toward having viable CPNT capabilities sooner rather than later.

Perhaps in response, during each of the past two fiscal years, Congress has appropriated about $15 million in additional funds on top of DOT OST-R’s budget request. Not surprisingly, Congress has been applying “significant pressure…on moving out and marching forward in expediting CPNT implementation,” Van Dyke said.

Yet implementation is not easy. Van Dyke foot stomped that, “DOT cannot recommend deploying additional technologies until they have been thoroughly tested, are well understood with regard to their own limitations and vulnerabilities and have been run through their paces just like GPS.”

Hence, we have this latest RFQ. It seeks proposals from CPNT vendors interested in allowing Volpe to test, evaluate and monitor their services’ performance against scenarios involving disruptions or manipulations of GPS/GNSS services and CPNT-specific threat vectors. The RFQ furthers the Rapid Phase of DOT’s CPNT Action Plan, with the aim of advancing CPNT adoption across federal interagency initiatives, in alignment with critical infrastructure PNT user requirements.

Responses to the RFQ must specify that the bidder’s CPNT services will be up and running, and in compliance with all government specs, within six months after award at one of these types of test ranges: Federal Government-hosted; government-aligned critical infrastructure or vendor-facilitated (caveat on this one: when the other two models are not appropriate and/or beneficial to the government). Once ready to roll, the expected period of performance for the selected vendors will be one year.

From Crawl to Run

This is not Volpe’s first rodeo on testing CPNT. In 2020, the Center conducted CPNT demonstrations that resulted in a report to Congress. As noted, Congress has since (FY22 and FY23 appropriations) provided a significant budget in support of those important recommendations. Between 2020 and now, DOT has continued to be deliberate in its approach toward both toughening and complementing PNT with other technologies.

On the bolstering side of the house, in the latter part of 2020, DOT OST-R started a pilot program with the agency’s Maritime Administration (MARAD) to evaluate CPNT technologies, as well as test anti GPS-jamming and spoofing capabilities using Controlled Reception Pattern Antennas (CRPA) on vessels. While CRPA proved effective, International Traffic in Arms Regulations (ITAR) restrictions on their civil use have created legal roadblocks to their deployment.

Also in 2020, in partnership with the Department of Homeland Security (DHS), DOT collaborated on the 2020 GPS Testing for Critical Infrastructure (GET-CI) live-sky event. The two plan to conduct another GET-CI event later this year.

DOT continues to seek anti GPS-jamming and spoofing capabilities, in addition to CPNT, Van Dyke said. “This is a two-pronged approach,” she said. “If we can get more out of GPS and make it less susceptible to jamming and spoofing, all the better. We don’t view this as an either-or scenario. We want to have as many tools in the toolbox as possible to address the potential disruption, denial or manipulation of PNT services. We need to have gap fillers. This will require additional equipment that can be adopted into end user applications.”

So, on the CPNT side, two years after doing its own demos, DOT held its first CPNT Roundtable to gather both internal and external stakeholder feedback on the best way forward. The Roundtable included industry vendors, federal partners such as the Department of Energy and the Department of Defense, as well as critical infrastructure owners and operators.

Van Dyke characterized those discussions and hearing from both sides as “enlightening.” She noted GPS has provided very reliable service for more than three decades, so critical infrastructure end users have naturally grown comfortable with its use. “It has U.S. Government performance commitments, and it has performance standards built around it,” she explained. “Critical infrastructure owners and operators view that new commercial technologies present a risk to these users. They want to know how it will perform, especially for safety of life applications. They want to understand the level of performance commitments from the manufacturers. They seek performance standards.”

The insights from the Roundtable helped to inform DOT’s thinking on a CPNT roadmap and ultimately informed its September 2023 CPNT Action Plan.

“We all agreed that the government needs to lead,” Van Dyke said. So the plan envisions DOT as a federal clearinghouse, of sorts, for CPNT tech. The goal, per Van Dyke, is to “give end users in the federal government a one-stop shop.” Generally speaking, industry will follow the government’s lead. “The government needs to take action for our own PNT applications first,” she continued. The idea is that critical infrastructure end users will leverage the “CPNT matrix” that DOT will create to shore up their own PNT.

After the CPNT Action Plan launched, things really started moving. That same month, Volpe issued the aforementioned CPNT RFI. Less than six months later, it put forth the current RFQ.

Where We Go From Here

Van Dyke told Inside GNSS they received “over two dozen responses” to the RFI but could not comment on how many of those actually met the mature TRL requirement.

Will DOT focus on global CNPT capabilities or more regional ones, terrestrial options, urban-centric tech or something else entirely? The answer may be all of the above. From Van Dyke’s perch, the primary thrust is to identify a reliable and diverse PNT ecosystem.

Of note, the CPNT tech sought in the RFQ gives priority to GNSS-independence. Van Dyke elaborated, “We need to facilitate end user adoption of CPNT technologies, not just focus on having additional signals in space.” She continued, “This is the opportunity to stress test other diverse CPNT technologies. Either these vendors will show that their tech really does work or, if not, we will learn how they can be improved upon.”

Where will the testing occur? The RFQ only mentions Joint Base Cape Cod, one of two locations previously used by Volpe for the 2020 demos. Van Dyke said DOT is talking with other federal agencies and departments to ensure geographic diversity for the test sites. Requests for comment from the Federal Aviation Administration (FAA), one of the leaders of the critical air domain, to see whether some of the uncrewed aircraft system (UAS) test or R&D sites (e.g., the Choctaw Nation of Oklahoma’s Daisy Ranch in Durant) or Section 383 (counter-UAS test sites) would be used, went unanswered. We will all apparently know more after DOT issues these awards.

But one thing is clear: from DOT’s perspective, it’s go time for CPNT. DOT remains confident, barring any unforeseen circumstances, that they will meet CPNT Plan timelines.

Van Dyke emphasized, “We have gone out with a solicitation that will likely result in multiple awards. We want diversity of technologies. We have put a lot of thought into the CPNT Plan and timeline. There is a sense of urgency on multiple fronts to now move out. And we intend to execute.”

Because the solicitation remains ongoing, DOT was also unable to provide any insights into exactly how a CPNT service provider could best present the potential viability, safety and economic benefits of their use case(s).

Regardless, Van Dyke did have a message to CPNT vendors, “Seriously consider applying for the solicitation. This is a really great opportunity and the most expeditious path for end user application. We view standing up these test ranges as bridging the gap to demystify these technologies to the end users.”

And this is just the beginning of something bigger. We know there are less mature CPNT technologies that will evolve and still have time to come to the table. There will be other phases over the next few years. In the meantime, we wait and watch to see what shakes out of this latest call for CPNT technologies.

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The Problem to be Solved

A picture paints 1,000 words. Just one look at a publicly available map that shows potential navigation system interference based on aircraft ADS-B Exchange data shows the ubiquitous nature of GPS jamming globally.

Not surprisingly, much of the Middle East, especially the eastern Mediterranean, Gaza, Iraq, Lebanon, Cyprus, Turkey and Armenia, all regularly see GPS jamming activity. Libya in North Africa remains a hot spot. Data from Europe indicates routine jamming around Russia, Ukraine, Poland, Romania, Lithuania, Latvia, Kaliningrad and Finland. India has its own trouble spots.

Military conflict across or near all these areas appear to be the common thread. GPS signal-interference constitutes a form of electronic warfare (EW). It negatively impacts a wide range of critical navigation-related functions, from targeting to basic command and control (C2). This form of EW frequently spills over into civil society, impacting basic everyday functions that rely on positioning navigation and timing (PNT), from driving maps and commercial flights to precision agriculture.

The pervasiveness of this threat has recently sparked efforts in both the United States and Europe to seek complementary PNT (CPNT) technologies and alternative PNT tech (A-PNT), respectively.

While that search remains ongoing, ANELLO has put forth a cost-effective, high-performance navigation sensor that aims to redefine navigation and positioning in contested environments. The company’s latest release is a 3-axis Silicon Photonics Optical Gyroscope (SiPhOG™).

Through the FOG of War

Fiber optic gyroscopes (FOGs) measure angular velocity and orientation, enabling autonomous systems without having to rely on global navigation and satellite systems (GNSS), such as the Global Positioning System (GPS).

FOGs sense rotation by measuring the interference of laser light traveling within a coil of optical fiber based on the “Sagnac effect” (a measurement principle based on the movement of an electromagnetic wave in a closed path around a finite area affected by the rotation rate of a given system).

Optical gyroscopes have no mechanical moving parts. This allows them to remain resistant to vibration, which translates into measurement reliability. This characteristic also means FOGs don’t require maintenance. It also makes them long-lasting.

For these reasons, aircraft, spacecraft, surface and subsurface ships and other autonomous vehicles have employed these accurate, precise rotation sensors in their navigation and guidance systems. In fact, they have become particularly invaluable in strategic and tactical grade long-term navigation in GNSS-denied environments.

But many of these high-precision FOGs, especially the large ones used in aviation and by the military, can cost tens of thousands of dollars. Some of the systems in helicopters and planes cost upwards of $100,000 apiece.

The true advancement in FOGS, and a huge value-add as autonomous systems become smaller and more agile, is in low size-weight-power and cost (SWAP-C). And that’s where Santa Clara-based ANELLO has put its focus.

Small But Mighty

In 2023, ANELLO introduced its single-axis SiPhOG™. At the time, the tech was the first SWAP-C optical gyro. This next-gen inertial nav sensor uses an on-chip waveguide manufacturing process, integrated with a patented silicon photonic integrated circuit.

The company’s processing approach integrates two chips (waveguides using silicon nitride and an integrated silicon photonics chip with couplers, splitters, phase modulators, detectors etc.). This enables high volume production because the units can be produced at the same fabs as integrated circuits. The company partners with Tower Semiconductor to manufacture its IMUs. Their process results in both a low cost and size (about an inch) previously thought impossible.

This year, the company upped its game by releasing a 3-axis optical gyro IMU, the ANELLO X3. This complete IMU can fit in the palm of your hand. It takes ANELLO’s tech higher and deeper, literally, by enabling navigation for “things that move in 3D space,” company co-founder and CEO Mario Paniccia said. The unit’s small SWAP-C makes it well suited for autonomous drones and maritime vehicles, among others.

The worldwide conflicts we continue to witness have taught us drones and robotics needed a solution to allow operations in GPS-challenged environments, Paniccia said.

“If a drone’s autopilot uses GPS, and this is disrupted or denied, that drone will hover, stop and crash,” he said. “That’s a big problem for which, until now, there was no real viable solution. Because the ANELLO X3 is optical, it cannot be jammed or spoofed.”

Paniccia continued, “Our ANELLO X3 allows for precise aerial navigation in GPS denied environments. It enables beyond visual line of sight (BVLOS) flights up to 10km with a lateral error of 100m (0.1%).”

This made-in-the-U.S. unit also incorporates an artificial intelligence (AI)-based sensor fusion engine with algorithms that automatically detect a loss of GPS and constantly track location to provide accurate positional information. Other key features include:

● <0.5°/hr Gyro Bias Instability
● <0.05°/✓hr Angular Random Walk
● <20mg Accel Bias Instability
● <5.0W Power Consumption
● <8 in3 Size
● <0.5lbs Weight
● RS-422 or UART Interfaces

A World of Possibilities

These features make the ANELLO X3 a solution for all-domain small and large autonomous defense and commercial applications alike. Paniccia noted users can put the ANELLO X3 “on anything that moves.” It can be employed indoors or outdoors on drones, robots, stabilizers and more.

The use cases and markets are endless, as are the possibilities for autonomous systems. For surface marine vessels, it can be used for maritime surveying, side-scan sonar and similar applications. Subsea, whether crewed (e.g., submarines) or unmanned underwater vehicles (UUVs), it can aid in hydrography. For traditional general aviation, helicopters or advanced aviation such as electric vertical takeoff and landing (eVTOL), the ANELLO X3 can establish operational roll, pitch and yaw data. For robotics in general, it can detect and make adjustments for changes in velocity, position or acceleration.

ANELLO Photonics is engaged in trials with its X3 with leaders across various markets, including construction, farming, robotics, trucking, UAVs, autonomous vehicles and the defense space.

The post From the CES24 Floor: ANELLO’s 3-Axis Optical Gyroscope IMU appeared first on Inside GNSS - Global Navigation Satellite Systems Engineering, Policy, and Design.

Earlier this year, the European Commission’s (EC) science and knowledge service, the Joint Research Centre (JRC), issued its report Assessing Alternative Positioning, Navigation, and Timing Technologies for Potential Deployment in the EU. It summarized the assessment of seven Alternative PNT (A-PNT) platforms which occurred during the eight month period between October 2021 and July 2022. It concluded that commercially available mature Alternative-PNT (A-PNT) technologies are already present in the market that can provide positioning and/or timing information separately from Global Navigation Satellite Systems (GNSS). It also concluded that a system of systems approach that incorporates a range of interoperable technologies, supported by standards, remains the lynchpin to resilient PNT. Will any of the technologies reviewed in the JRC Report come out on top in the U.S. as serious contenders for CPNT?

What’s In A Name?

Before comparing the JRC and DOT requirements as a potential indicator of which technologies may prevail in a U.S. contest for the same, the first issue is whether or not the DOT’s CNPT and the EC’s A-PNT even refer to the same thing. Spoiler alert: they kinda don’t.

It’s nuanced. The EC defines A-PNT as “backup solutions,” meaning “technologies providing PNT independently from GNSS.”(1)

A look at the Volpe Report from a couple years ago would lead one to believe the EC and DOT are on exactly the same page. Back then, both US law, DOT policy and research statements lumped together the terms CPNT and “backup GPS capability” or “GPS backup” technologies. Both essentially meant “capabilities to back up and complement the PNT capabilities of the GPS.”(2) (Gotta love definitions that use the same term to define the term in question.) In fact, even the September 2023 DOT CPNT Plan defines CPNT systems as resilient PNT technologies that could offer complementary service in the event of GPS disruption, denial, or
manipulation.(3)

While this sounds like more of the same, the Plan also shows an important evolution of thinking. In describing the tech DOT seeks, it says “CPNT technologies must provide increased capability, not viewed (sic) only a backup to GPS.”(3) Read that again.

It must also, according to the Plan, have a “mature threat posture against capable actors.” And the Federal Government will act as “lead investor/subscriber of services” across key domains: maritime, rail, and surface applications.

That’s why we see what we see in DOT’s recent RFI. (Previous IG coverage here: https://insidegnss.com/all-jammed-up-dot-urgently-seeks-complementary-pnt/) And there’s more. A glaring difference between A-PNT and CPNT, at least from this initial testing volley, lies in the selection criteria for potential participants. The JRC required a Technology Readiness Level (TRL) greater than 5 for position/navigation services or greater than 6 for timing services. The DOT RFI required a TRL of 8 or beyond. This requirement harkens back to the CPNT plan indicating a need for “mature” technology. A TRL of 8 or 9 indicates something already in use, off-the-shelf if you will, on the commercial market. It underscores the DOT’s current sense of urgency to find it.

A close read of the RFI also shows the DOT seeks interoperable tech. It’s not looking for stand alone, apples-to-oranges systems. It’s looking for an entire CPNT ecoverse to bridge the gap should GPS go Poof!

Yet among all of these differences, the needs driving these different requirements are generally the same here and across the pond.

The Driving Need

Both the U.S. and EC rely heavily on GNSS services for PNT, across a myriad of burgeoning sectors from car-sharing platforms, intelligent logistics solutions, autonomous transit systems (e.g., vehicles, vessels, and aircraft), geolocation-based applications, precision agriculture and more. Perhaps more importantly, vital infrastructures, deemed strategic linchpins for modern societal operations, leverage PNT services, particularly the timing proficiencies. These include telecommunications, energy, finance and a spectrum of transportation modalities (road, maritime and aviation). The need for, and the characteristics of, likely user communities who need A-PNT/CNPT are very similar globally.

With regard to the European front, the JRC Report indicated that an uptick in GNSS jamming and spoofing incidents presents a threat to the GNSS-driven EUR 2 trillion socio-economic boom across Europe (the EU27, UK, Norway and Switzerland) projected by 2027. In terms of dollars and sense, the U.S. and United Kingdom (U.K.) threat assessments have posited that the economic detriment of GNSS unavailability could approximate a EUR 1 billion daily.

These threat estimates do not include GPS jamming incidents in or around the eight countries still pending EU membership, most notably Ukraine.(4) Spillover GPS jamming effects from Russian electronic warfare (EW) has already adversely impacted commercial airlines and shipping in both Bulgaria and Romania. Some have posited that this war-related EW activity has significant potential to destabilize the entire Black Sea region.(5)

In response to these ever-increasing vulnerabilities, to bolster the resilience and ensure the continuity of critical operations, the U.S., the European Union (EU) and U.K., among others, look to find and implement robust and resilient PNT services, whether as alternatives, backups to or completely autonomous-from-but-interoperable-with conventional GNSS services on their own home fronts.

So, does the JRC Report provide any relevant insights for a DOT CPNT solution? Answer: a few.

Some Clues

While the EC characterizes its test results as a “qualitative assessment,” rather than a benchmark, some things in the JRC Report nevertheless can provide a bit of insight into some of the technologies the DOT may be eyeballing for holistic U.S. CPNT system-of-systems solutions. (Previous IG coverage provides a detailed explanation as to how the JRC demos were conducted: https://insidegnss.com/backing-up-gnss/).

Let’s focus on the capabilities to knock out a few contenders right away, at least in terms of independent tech that can act as more than just a back up to GPS, meaning one that could go it alone (while also working well with others). The JRC demonstrations involved seven selected providers. OPNT, 7 Solutions SL, SCPTime and GMV focused on timing services only. That makes them interesting but not the final answer. Satelles, Locata and NextNav successfully demonstrated both positioning and timing. That puts them in the ring.

Next, let’s use the TRL level to show that at least one contender remains down for the count and show our Top 3 are still in the fight. As noted, the EC only required a TRL greater than 5 for position/navigation services or greater than 6 for timing services; DOT seeks a TRL of 8 or higher.

Based on the TRL alone, the DOT RFI’s more stringent criteria GMV Aerospace and Defence SAU is K.O.’d. Although the key technologies used in the company’s WANtime solution all have a high TRL (minimum 6), which qualifies it for the JRC project, each technology individually has a different TRL. Combined their average TRL levels put GMV Aero’s tech at an estimated overall TRL of 7. (6) For example, its atomic clocks, clock modeling and steering and time transfer technology, based in GNSS or TWSTFT and used in the operational generation of Galileo System Time (GST) in the Galileo Precise Timing Facilities (PTFs), can all be considered TRL 9. The company gave its White Rabbit (WR) a TRL of 8, as it noted that “especially long-range WR, poses quite a few challenges and requires careful network engineering.” The application of DTM, packet-exchange network technology, to timing applications is still under development and comes in at TRL 7. Higher-precision network time protocol (NTP) is a relatively new, experimental area and can be considered TRL 6.

On the other hand, Satelle’s LEO satellites for satellite timing and location (7), NextNav’s TerraPoiNT ground-based solution that leverages existing cellular LTE/5G signals and dedicated Signal Sensors and/or TerraPoiNT transmitters (8) are both reported as TRL 9.

While the TRL level for Locata’s LocataNets, a system of terrestrial beacons to provide PNT signals to dedicated receivers in a localized area, were not readily accessible, its commercial deployment in different environments like open-cut mines and harbors, combined with its testing by significant entities like the U.S. Air Force at the White Sands Missile Range, suggests its mature stage in the TRL spectrum, possibly at or near TRL 9. This pseudolite alternative uses multiple, geographically dispersed, terrestrial transmitters to provide passive or pseudo ranging signals that can be used to accurately calculate position. Notably, the EU ranks pseudolites in general at a TRL of 9. (9)

Assuming Satelles, Locata and NextNav have thrown their hats in the ring for DOT’s RFI, and that they can meet DOT’s security and interoperability requirements, their tech illustrates a sea change from reliance on middle earth orbit (MEO) satellites for PNT. Satelles’ solution orbits in LEO, while Locata and NextNav are both terrestrial based. The times (no pun) they may be a changin’.

Next Steps

So, where do we go from here? In Europe, even though the EC just put out its European Radio Navigation Plan 2023 in June, it already has plans in the works to update it. Europe also intends to evolve Galileo and EGNOS and issue new regulations. What exactly it intends to do with the JRC 7, if you will, remains a mystery.

But likely at least 3 of those 7 companies may have a real shot here in the U.S. The DOT’s recent RFI. That’s the first step. The next would be the issuance of a request for proposal (RFP) to actually make that testing a reality. Applying the tech to real world use cases would be the goal. To do that, as noted way back in Volpe’s 2021 report, and now the JRC report, also requires the creation of standards.

For now, who’s really positioned to navigate DOT’s process, and what’s the timing? We may have teased out a few clues here, but, in the end, only time will tell.

References:

1. https://joint-research-centre.ec.europa.eu/scientific-activities-z/alternative-pnt_en#:~:text=To%20address%20this%20threat%2C%20it,or%20A%2DPNT%20for%20short.
2. https://www.transportation.gov/sites/dot.gov/files/2021-01/FY%2718%20NDAA%20Section%201606%20DOT%20Report%20to%20Congress_Combinedv2_January%202021.pdf
3. https://www.transportation.gov/sites/dot.gov/files/2023-09/DOT%20Complementary%20PNT%20Action%20Plan_Final.pdf
4. https://european-union.europa.eu/principles-countries-history/joining-eu_en
5. https://www.rferl.org/a/russia-gps-jamming-black-sea-romania-bulgaria-ukraine/32655397.html
6. https://joint-research-centre.ec.europa.eu/system/files/2023-02/Report_GMV.pdf
7. https://satelles.com/wp-content/uploads/pdf/Satelles-STL-Data-Sheet.pdf
8. https://nextnav.com/gps-alternative/
9. https://data.consilium.europa.eu/doc/document/ST-10259-2023-INIT/en/pdf
10. https://www.minalogic.com/en/member-news/scptime-selected-by-the-european-commission/
11. https://joint-research-centre.ec.europa.eu/system/files/2023-02/Report_7Sol.pdf

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The Plan

The DOT’s CPNT Action Plan, issued this September, provides a comprehensive roadmap to ensure the safety, security, and efficiency of critical infrastructure in the face of potential GPS disruptions through the adoption of CPNT technologies.

Stakeholder engagement across the PNT enterprise, including providers of PNT services and critical infrastructure owners and operators, ranks high among the plan’s key strategies and actions. So does the development of CPNT solutions specifications and standards. The plan further includes a goal of establishing field trials and test ranges to evaluate the performance and resilience of domain-specific (e.g., maritime, rail, and surface applications) CPNT technologies, based on quantitative performance metrics.

The DOT also plans to act as the federal PNT services clearinghouse to provide real-time situational awareness, performance monitoring, and response capabilities, and as the government’s lead adopter and purchaser of PNT services to accelerate testing and market development in the private sector. The department appears to have fast-tracked this federal marketplace strategy with the issuance of an RFI to industry on CNPT tech.

The RFI

On September 11th, DOT’s Volpe Center issued a 15-day quick-turn RFI to industry seeking information about the “availability and interest in carrying out a small-scale deployment of high-level technology at a field test range to characterize the capabilities and limitations of such technologies to provide PNT information that meet critical infrastructure needs when GPS service is not available and/or degraded due environmental, unintentional, and/or intentional disruptions.” It then extended the deadline to October 10th.

The RFI, which specifically seeks to field test CPNT technology that stands at a Technology Readiness Level (TRL) of eight or beyond, signals the immediate need for a complete solution from core infrastructure to User Equipment (UE).

In an apparent effort to spur broader assimilation of CPNT technology, the RFI outlines a vision of three field test range models to nurture a collaborative environment between CPNT technology vendors and critical infrastructure consumers. It delineates a meticulous setup for examination at the selected Test Range Sites, where either the U.S. Government or designated operators will facilitate the CPNT technologies’ deployment.

To this end, the DOT seeks detailed commentary on test range deployment logistics, across a spectrum of scenarios (e.g., varying levels of urbanization, terrain diversity, meteorological conditions, and indoor/outdoor environments), potential user sectors, exemplar use-cases, as well as an analysis of the economic and safety dividends in alignment with various critical infrastructure sectors. It requires diagrams and achievable execution timelines for such field trial testing.

The DOT set the bar high. Companies replying to this RFI must meticulously outline the technical specifications of their CPNT technology, with a focus on accuracy, integrity, and resilience, especially under adverse GNSS conditions. They must also thoroughly explain their technology’s resilience against a range of signal threats, both intentional and unintentional, including jamming and spoofing.

Additionally, they must produce sufficient data on information assurance across the company’s supply-chain, operational security, system control and maintenance to illustrate robust security, consistent with the national cybersecurity framework.

The RFI places the coherence among system components and their efficacy in an operational environment high as a top priority. The technology must have also undergone a stringent testing and evaluation process, manifesting its designed functionality with precision.

This RFI underscores the DOT’s escalating endeavor to bolster the resilience of the nation’s critical infrastructure against disruptions to GPS. It reflects a growing awareness of the potential risks associated with GPS dependencies and represents an organized effort to mitigate them. But why the sense of urgency now?

The Timing

The problem of potential GNSS disruptions, whether due to natural phenomena, technical issues, or deliberate interference (e.g., jamming or spoofing) is not a new one. It has been well documented, for some time now, that the absence or degradation of GNSS signals can have significant implications for safety, security, and economic activities across the defense enterprise and civil society.

The pressing need for resilient PNT solutions that can function if GNSS gets knocked off line seems to have a direct correlation to current events – in particular, the prevalence of GNSS jamming in both the Hamas-Israel and Russia-Ukraine conflicts. Interfering with GNSS signals, itself a form of electronic warfare (EW), enables combatants to undermine a wide range of adversary capabilities, from simple navigation to advanced weapon systems that rely on GNSS for targeting. The repercussions of these tactics, however, have transcended the battlefield. They’ve extended into the digital infrastructure and electromagnetic spectrum upon which civilian infrastructure relies for precise PNT data.

In the theater of conflict between Israel and Hamas, the strategic use of GNSS jamming has emerged as a significant player. As the hostilities began, Hamas employed GNSS jamming to impede Israeli communication networks. To neutralize aerial threats from drones, shield against airborne assaults and thwart Hamas’s ground offensive and missile launches, Israel intensified its own use of GNSS jamming. This jamming had a spillover effect on civil aviation. In one case, a potent GNSS jammer deployed at an airforce base had reverberations on regional civil aviation.

Similarly, GNSS jamming has been a significant issue in the Russia-Ukraine conflict. While Russia’s military invasion began in February 2021, it has reportedly been engaged in GNSS jamming activities in the region since at least 2014. Over the past several months, these activities have ramped up to a reported 15 regions. Among other concerns, this could cause significant navigational challenges for civil aircraft.

These persistent GNSS jamming activities reflect a broader strategy of EW as a critical component of modern military operations. The problem is that GNSS is a dual-use technology. Many civilian sectors also depend heavily on GNSS. Its disruption can have wide-ranging implications on both the military and civilian sectors alike. For the U.S. government, these electronic skirmishes have underscored the vulnerability of both mil-civ targets to GNSS disruptions. They appear to have propelled the DOT’s current quest for robust CPNT systems capable of withstanding electronic threats. So, who is answering the call?

The Contenders

The specific responses to the US DOT RFI on CPNT at TRL 8 remain unavailable to the public. However, several companies which have engaged in demonstrations and evaluations concerning PNT technologies, both in the US and in Europe, have likely responded.

Earlier this year, the European Joint Research Centre conducted a test campaign to evaluate various Alternative Position, Navigation and Timing (A-PNT) platforms that could provide precise PNT without the use of navigation satellites. The rigorous assessment spanned over eight months. It involved evaluations in both indoor and outdoor environments at both the JRC premises and other locations and encompassed time transfer over the air, fiber, and wired channels. The campaign identified seven companies as having mature technologies ready to take on CPNT: OPNT, Seven Solutions SL, SCPTime, GMV Aerospace and Defence SAU, Satelles Inc., Locata Corporation Pty Ltd and NextNav.

Some of these same companies had also previously participated in U.S. technology demonstrations, specifically Volpe Center’s 2020 demos. Despite the showing of these companies in 2020, in its 400+ page final report to Congress on the matter in 2021, DOT opined that “none of the systems can universally backup the positioning and navigations capabilities provided by GPS and its augmentations.”

Perhaps in the three years between the Volpe and JRC demos, CPNT technology has leap-frogged forward. Regardless, there’s a good chance that at least a handful of the companies that showcased their tech in both the U.S. and Europe have thrown their hats in the ring to respond to the DOT’s most recent call for CPNT tech.

In the meantime, electronic threats continue to surge. Let’s hope global PNT authorities pick some winners to shore up PNT…before we get jammed up.

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If beyond visual line of sight (BVLOS) operations are the “Holy Grail” of the UAS industry, harnessing the capability of non-terrestrial networks (NTNs), or Space-Based Adaptive Communications Node networks, appears to be the equivalent for a 5G communication system network—particularly in low earth orbit (LEO) satellite communications (SatComs) constellations.

UAS, among many other systems, can play a vital role in developing requirements, which could, in turn, help mitigate current technological limitations for BVLOS and a wide range of other use cases that depend on accurate positioning, navigation and timing (PNT). However, as in so many other areas of emerging technology, challenges in implementation and standardization remain unsolved. Here’s a rundown of the state of play for 5G LEO SatCom networks.

The Basic Plan

To appreciate the game-changing nature of 5G New Radio (NR), you must first have a basic understanding of how traditional mobile telecommunications work.

Telecoms traditionally consist of four key components, according to Ericsson, an information and communication technology (ICT) service provider. Most of us engage directly with user equipment (UE) devices such as smartphones and tablets. The Radio Access Network (RAN) wirelessly connects UEs using radio frequencies (RF). Coordination between various parts of the RAN and the connection to the internet occurs through the core network (CN). Finally, the transport network supplies the connection between the RAN and the CN.

Complex integrated hardware and software enable these functions, even in traditional comms. Baseband equipment that performs all of the signal processing functions required for wireless communications (e.g., for multiple antennas, to detect/correct transmission errors, provide security and manage resources) contains high performance electronics and cutting edge software. Radios ensure signal transmissions travel on the correct bands at the required voltage and actually convert digital information into those signals. Antennas beam out those electric signals into radio waves.

5G, which requires Multiple-Input Multiple-Output (MIMO), adds layers of complexity to this basic telecom system. It requires cross-functional integration, such as integrating radios and baseband hardware and software with antennas. 5G NR RAN (which replaces the Long Term Evolution (LTE) high speed and low latency RAN) and CN software can be deployed and managed on the same infrastructure. 

For this reason, RAN radios (baseband and antenna-integrated) and CN sites depend on software, on each other and on complex code. For maximum coverage, companies have built additional base radio stations, called gNB (Next Generation/gNodeB, which replaces the eNB or eNodeB or Evolved Node B) and deployed AI and ML to orchestrate and balance traffic. 

Why does this matter? 5G’s unified interface enables higher speeds, reduces latency and increases the availability and reliability of connections. 

The Value Proposition

According to Qualcomm, 5G will fuel “massive IoT” and drive global growth. The company’s landmark 5G Economy Study found 5G could potentially enable up to $13.1 trillion worth of goods and services across a diverse group of businesses worldwide by 2035. More than 60 countries have already deployed 5G.

Now add in NTNs, which deliver 5G/NR service via space (satellite) or air (airborne platform) to the 5G mix. This multi-layered network can include SatCom networks, high altitude platform systems (HAPS), UAS and other air-to-ground networks.

According to 3GPP, the NTN 5G value proposition is clear. NTN systems can significantly bolster 5G service continuity where a single or series of combined terrestrial networks cannot, particularly for mobility assets and mission-critical communications. NTN can bridge 5G service coverage gaps where terrestrial networks do not exist or simply do not reach. This includes oceans, deserts, wildernesses and urban areas. Scalability, through NTN’s wide area coverage and ability to multicast, also tops its list of benefits. 

NTN 5G can support a wide range of use cases, including aeronautical and maritime tracking systems. Specifically, Automatic Dependent Surveillance-Broadcast (ADS-B), which is based on the capability of the aircraft to navigate to a destination using GNSS data and barometric altitude, allows for communication with air traffic control, cooperative surveillance, separation and situational awareness. It depends on aircraft navigation system data derived primarily from GNSS signals and then broadcast to aircraft and ground-deployed infrastructure. 

But this infrastructure does not exist in a number of areas, including over oceans and in the Arctic. LEO-based ADS-B receivers could contribute to the ATC relay network. This would result in low latency and secure coverage globally. In the maritime sector, the equivalent tracking system, Automatic Identification System (AIS), also benefits from space-based receivers.

The benefits of NTN 5G extend beyond transportation and more broadly for internet of things (IoT) applications, from surveillance of infrastructure to precision agriculture. 

Standards Moving Forward

The 3rd Generation Partnership Project (3GPP), a global partnership of telecommunications standard development organizations, started working on 5G NR NTN about 5 years ago. Its first study, Release 15 (Rel-15) documented in TR 38.811, targeted deployment scenarios and models that included not only LEO and HAPS, but GEO satellites as well. It addressed issues such as relevant beams, elevation angles, satellite deployment footprint, various NTN terminals and antenna arrays. 

The follow on study, Rel-16, focused on minimum viable architecture, higher layer protocols, and physical layer aspects (TR 38.821). This study concluded that the group’s NR work provided a solid basis to support NTN. It identified additional areas of study including: timing relationships, uplink time and frequency synchronization, and hybrid automatic repeat request (HARQ), a combination of high-rate forward error correction (FEC) and automatic repeat request (ARQ), essential for reliable data transmissions.

Earlier this year, ratified Rel-17 focused on 5G system enhancements. Among other things, Release 17 involves physical layer aspects, protocols, architecture and radio resource management. This study assumes all UEs have GNSS capabilities. 3GPP “froze” (meaning no further functions can be added to the specification) the Protocols for this study in March 2022 and the Protocol Code (OpenAPI) in June. According to 3GPP, the “Release 17 Description; Summary of Rel-17 Work Items” (TR21.917) remains in production. 

In the meantime, 3GPP launched the Rel-18 study. It focuses on 5G Advanced, addressing extraterritorial coverage of satellites and high altitude systems.

Progress continues to move forward on the coding side of the house, courtesy of the OpenAirInterface Software Alliance (OSA). This is significant because many of these systems rely on complex code stacks. The OSA, a French non-profit organization established in 2014 and funded by corporate sponsors, is the home of OpenAirInterface (OAI). OAI, an open software endeavor, has gathered a community of developers from around the world who work together to build wireless cellular RAN and CN technologies. 

The OSA OAI 5G Project Group seeks to develop and deliver a 3GPP compatible 5G gNB RAN software stack under the OAI Public License V1.1. In October, the group provided an OAI codebase status update and development roadmap.

Simultaneously, the organization’s related OAI 5G-LEO extension for 5G satellite links aims to use the OAI as a tool to assist in 5G NTN R&D. This 5G-LEO Project has four main objectives, according to the European Space Agency (ESA):

1. Select a 5G-LEO baseline scenario for 3GPP NR-NTN system deployments to implement and verify with the extended OAI library.

2. Identify fundamental codebase gaps and changes to extend OAI to the 5G-LEO baseline. 

3. Implement required OAI code adaptations for the different layers of the 3GPP protocol stack to support 5G-LEO within Rel-17 and potentially in Rel-18.

4. Set up an end-to-end 5G-LEO demonstrator in the lab for experimental validation of the OAI extension for the 5G-LEO baseline scenario.

This two-phase project, started in December 2021, is in its second phase. It’s focused on implementation, software compliance and demonstration.

Challenges and Stratospheric Possibilities

R&D continues to tackle other challenges that must be mitigated for successful LEO-based 5G NTN. Propagation delays and large Doppler shifts caused by moving cells rank high among them.

Propagation delays result in latency. Depending on the satellite’s altitude, long distances between satellite constellations, ground stations, and user terminals cause time delays in radio wave transmissions. While delays from LEO satellites are much shorter than higher altitude GEO satellites, the constellation and ground station deployments must be larger to cover wider areas. This can increase costs. Groups are exploring workarounds such as sat-to-sat relays, or mesh networks for CN functions, to mitigate these issues.

On the military side, the same mitigation measures used to solve common latency issues in GEO MIL/SATCOM applications can be applied to a LEO MIL/SATCOM architecture, said Jason “JD” Danieli, CEO of Colorado-based Giuseppe Space Enterprises. 

“Modeling, simulation and analysis, as we commonly refer to as MS&A, is an extremely important first step prior to deploying new tech. There are so many variables to consider and account for. A common SW tool, such as MATLAB, is just one of many tools we consider when solutioning,” Danieli said. “We attempt to address issues prior to deployment such as interoperability, performance and resiliency.” 

Research also remains ongoing to address Doppler effects in the LEO orbit. This phenomenon describes the increases (or decreases) in the frequency of sound, light or other waves as the source and observer move toward (or away from) each other. Waves emitted by a source traveling toward an observer get compressed. The LEO satellites and airborne platforms for 5G NTN move very fast while the user terminal remains either stationary or moves slowly. This results in large Doppler shifts experienced by the receiver, leading to communication degradations between transmitters and receivers. This is why 3GPP assumes NTN devices will be equipped with a GNSS chipset to determine position and calculate the needed frequency adjustments. 

But GNSS has its own challenges in terms of vulnerability. Efforts to make PNT more resilient continue to churn…slowly. 

On the bright side, LEO satellites offer several attributes that are attractive to supplement GNSS for positioning and timing. This includes an abundance of signals, favorable geometric configurations, and diverse signal frequencies. 

“With 5G NTN entering the stage, we will have even more satellite signals to consider on top of the 3,000+ LEO satellites whose signals have already shown potential to supplement GNSS,” said StarNav CEO Joshua Morales, who has spent nine years building PNT systems that use cellular and LEO satellite signals as a backup to GPS.

New partnerships have cropped up to tackle these challenges and take advantage of the benefits that NTN has for the future of 5G. Last summer, for example, Ericsson, Qualcomm Technologies, Inc. and French aerospace company Thales announced a partnership for the first testing and validation of 5G NTN. This work aims to validate 3GPP’s assumption that 5G NTN can be supported in a smartphone form factor. Initial tests are taking place in an emulated space environment in France. 

With the possibility of successful 5G NTN just within our grasp, we can no longer just say the sky’s the limit—because the possibilities are truly out of this world. 

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A Congressionally-mandated independent technical review from the National Academies of Sciences, Engineering, and Medicine (NASEM) recently found that Ligado Networks’ low-power terrestrial mobile satellite services (MSS) in the L-band may not harm most commercial uses but will, in fact, interfere with GPS for high precision receivers, Department of Defense (DoD) missions and downlinks from Iridium satellite terminals.

To pile on, mitigation measures may not be practical “at operationally relevant time scales or at reasonable cost.” The NASEM report also suggested FCC tighten up its receiver standards and spectrum-related proceedings in the future. Let’s review the bidding.

How Did We Get Here?

April marked the 2-year anniversary of the FCC granting the conditional and modified license (FCC 20-48) for Ligado’s national MSS network. But the back-and-forth on concerns about near-band interference goes back more than 20 years. The project’s history, dotted with stops and starts (including during the bankruptcy of Ligado’s precursor company LightSquared) and contradictory testing results has created a lengthy public record rife with controversy and emotion.

In the one corner, stands Ligado. Its vision is “to modernize American infrastructure by connecting the Industrial Internet of Things” with state-of-the-art satellite technology and plans to deploy Custom Private Networks to provide the cutting edge technology needed for the future of 5G. Ligado believes interference claims have been overblown and that potential interference can be mitigated, and stands ready to discuss how to do that.

On the other side of the ring, we have the National Telecommunications and Information Administration (NTIA) on behalf of the executive branch, industry, trade associations and Ligado opposition groups such as the Keep GPS Working Coalition. This crowd remains adamant that Ligado’s L-spectrum block will pose a threat to the viability of civil and military GPS receivers across the country.

In 2020, when the FCC unanimously and conditionally approved Ligado’s amended license request, these opponents pled with the FCC to both halt the creation of Ligado’s network and reconsider its decision. In January 2021, the FCC struck down the request to halt Ligado’s progress. However, it still hasn’t ruled on the reconsideration issue.

Much of the debate around the propriety of Ligado’s license is on whether the 1 dB C/N0 interference metric proposed by the feds, but not embraced by the FCC in its ruling for Ligado, is the correct standard to use.

In the midst of this bout, Congress jumped in to referee and ultimately leveraged its power of the purse. In Section 1661 of the 2021 National Defense Authorization Act (NDAA), Congress stopped the DoD from using government funds for technical or information exchanges with Ligado or to retrofit affected equipment, required the Department to submit estimates of reimbursable costs for any retrofit, and directed the DoD to charter an independent NASEM review.

At the heart of this review, NASEM was to compare “the two different approaches used for evaluation of potential harmful interference” and submit a report. The two other elements of NASEM’s task included assessing the: (1) likelihood that the authorized Ligado service will create harmful interference to GPS, MSS and other commercial or DoD services and operations and (2) feasibility, practicality and effectiveness of the measures in the FCC order to mitigate harmful interference effects on DoD devices, operations and activities.

NASEM got a late start and missed its 270-day deadline. However, its effort can be characterized as nothing short of herculean. The group, led by Committee Chair Michael McQuade, Ph.D., strategic advisor to the president at Carnegie Mellon University, listened to dozens of hours of live testimony and reviewed almost 100 documents over several months before rendering the following conclusions on the three tasks:

TASK 1: Approaches to Evaluating Harmful Interference Concerns. The committee determined that neither of the NTIA or Ligado approaches to evaluating harmful interference concerns effectively mitigates the risk of harmful interference.

While both approaches have a role to play in such evaluations, and the NTIA signal-to-noise ratio (SNR) approach may be a bit better than Ligado’s position measurement approach, each has serious flaws.

The SNR approach, the report found, is inflexible and, in some cases, has an overly conservative emission limit because “no single value for signal-to-noise degradation determines when the various types of possible harm to receiver performance will become significant.” The measurement approach depends on a test sampling approach too narrow to apply to the many and varied uses of the GPS system. The mic drop portion states:

“Ultimately, both proposed approaches are cumbersome, owing to the intensive, device-by-device testing required. They do not provide an engineerable, predictable standard that new entrants can readily use to evaluate impact. As such, these approaches impede progress in making more efficient and effective use of the spectrum.”

TASK 2: Harmful Interference to GPS and Mobile Satellite Services. In Ligado’s favor, the report found that, as authorized by the FCC, most commercially produced general navigation, timing, cellular or certified aviation GPS receivers will not experience significant harmful interference from Ligado emissions.

That said, critical high-precision receivers remain the most vulnerable to significant harmful interference from Ligado operations, as do downlinks for Iridium terminals within up to 732 meters (“a significant range”) of Ligado user terminals operating in the UL1 band.

The report discussed DoD systems and missions in a non-public and classified annex, but noted the DoD and agency partner testing demonstrated unacceptable harmful interference to national security missions.

The fix? The report found current state-of-the-art technology could be used to build a receiver robust enough to peacefully coexist with Ligado signals and achieve “good performance” for any GPS application. But, see the conclusions on task 3…

TASK 3: Feasibility, Practicality and Effectiveness of Mitigation Measures in the FCC Order. The FCC’s proposed mitigation measures included, among other things, exclusion zones for Ligado emitters, replacing antennas, filters or full receivers, enabling a “kill switch” to turn off Ligado emitters in some areas and other negotiated mitigations between Ligado and the affected parties.

The report found that while the proposed mitigations may be effective for DoD and national security end-users, where these are immediately available, such mitigation is neither satisfactory nor practical without both extensive dialogue among the impacted parties combined with long and expensive operational test certifications. On the commercial side (even commercial tech that DoD employs), “mitigation may not be practical at operationally relevant time scales or at reasonable cost.”

So, Where Are We?

The bottom line: no perfect interference standard exists; most commercial GPS will be OK but really important national security and satellite tech will experience inference from the Ligado emitter; state-of-the-art tech could help mitigate GPS interference, but would require collaboration between the parties, would take a really long time and would be expensive.

And yet both sides touted the report as a win.

Ligado professed in a statement, “The NAS(EM) found what the nation’s experts at the FCC already determined: A small percentage of very old and poorly designed GPS devices may require upgrading. Ligado, in tandem with the FCC, established a program two years ago to upgrade or replace federal equipment, and we remain ready to help any agency that comes forward with outdated devices. So far, none have.”

Not surprisingly, the DoD took a different view of the report:

“The NASEM study confirms that Ligado’s system will interfere with DoD GPS receivers, which include high-precision GPS receivers. The study also confirms that Iridium satellite communications will experience harmful interference caused by Ligado user terminals. Further, the study notes that when DoD’s testing approach, which is based on signal-to-noise ratio, is correctly applied, it is the more comprehensive and informative approach to assessing interference. The study also concludes that the Federal Communication Commission’s (FCC) proposed mitigation and replacement measures are impractical, cost prohibitive, and possibly ineffective.

These conclusions are consistent with DoD’s longstanding view that Ligado’s system will interfere with critical GPS receivers and that it is impractical to mitigate the impact of that interference.”

As both sides chalk the NASEM report up as a validation of their position, much work remains to be done.

Where Do We Go From Here?

For one, the FCC needs to move out—either way—on the pending Petition for Reconsideration. Enough is enough. In the latest move in that arena, on October 13, a host of businesses and associations, jointly requested the FCC to consider the unclassified portion of the NASEM report “to ensure completeness of the record” for the pending petitions for reconsideration.

As we know, however, the FCC has not taken any action on the Ligado proceedings since early last year. The Commission, which exists independent of the White House, remains deadlocked in a 50/50 split and one member short of a full majority. Meanwhile, the Senate continues to stonewall the appointment of Democratic nominee, Gigi Sohn, to the FCC. Sohn’s appointment would seal a Democratic majority. Not surprisingly, Republicans have stiff-armed her nomination, putting off the vote for more than a year now. Sohn would have given Chairwoman Jessica Rosenworcel the vote needed to pursue rulemakings opposed by the commission’s Republicans.

According to Jennifer Richter, Partner and Head of the communications and information technology practice at Akin Gump, an award-winning global law firm, the Commission does not need to wait. “If Chairwoman Rosenworcel has a majority on any item, that item can pass,” she said. That means the FCC could not only take action on the petition, but also move out on several reasonable suggestions in the NASEM report.

To start, the FCC could update its definition of “harmful interference.” The FCC currently defines it as “interference which endangers the functioning of a radionavigation service or of other safety services or seriously degrades, obstructs, or repeatedly interrupts a radiocommunication service operating in accordance with [the International Telecommunication Union] Radio Regulations.” The committee blamed this non-quantifiable definition of harmful interference for the years long Ligado quagmire, which it says, “has tied up spectrum, as well as untold resources of the participants.”

What could work? In the case of GPS, a harmful interference criterion that accounts for position error effects, acquisition and tracking challenges, and continuity of service potentially based on a maximum limit for degradation of C/N0, possible effects of out-of-band emissions (OOBE) and adjacent-band signals in a designated frequency range for a reasonably well designed receiver to dictate an adjacent-band power mask that the FCC would guarantee going forward for a given period of time.

The FCC might also consider revising design and implementation standards for receivers themselves, in a nuanced way. As the report noted, “One must…distinguish between receiver standards that address operation in the current environment and those that might protect operation in the presence of some future uses that were vastly different in their impact.”

Then there’s the matter of spectrum, and how it should be allocated from a process standpoint. The FCC has no cohesive policy about rights of current users, the impact of equipment lifetime, business models, and similar essential considerations. According to the report, “This must be established outside the pressures of any one spectrum decision” and “current actions supporting the repurposing of spectrum is at best, ad hoc, and certainly does not operate on the same timeline as that which the technology is capable of changing.”

Appearances also matter. The committee suggested all parties might have found the proceedings more palatable had the FCC made independent findings of fact instead of quoting out of the various parties’ filings.

Fairness aside, these issues always boil down to money. But the FCC also has no policies for equipment owner’s rights when it comes to spectrum. The report outlined issues to think about such as: “What is the lifetime for any mitigation responsibility? What is the responsibility for receiver performance? How is any such responsibility addressed administratively?”

Finally, revectoring processes to take a more collaborative, instead of litigious, approach would go a long way to ending “successive cycles of argument.” Steps might include jointly studying and testing the impact of proposed regimes using agreed-upon criteria, experiments and cases. Gone are the days of completely segregated federal and non-federal spectrum.

If the FCC encouraged both communities to have more internal and external coordination and related negotiation, we could all have a higher degree of confidence in the process, our federal agencies and the equitability of spectrum allocation.

Read the NASEM report. You can read the full Ligado report here:
https://nap.nationalacademies.org/read/26611/chapter/1.

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The resilience of the Global Navigation and Satellite System (GNSS) that enables mission and life-critical position, navigation and timing (PNT) remains a topic of interest around the world. Threats to PNT continue to increase exponentially. Space-based threats rank high among them, including space debris.

Recently, the Federal Communications Commission (FCC) caused a bit of a stir by indicating it plans to issue regulations governing activities in space that currently fall between jurisdictional policy lines, including on the controversial matter of debris removal. Will there be clarity on this issue for the PNT industry soon despite the clutter among the stars and in the halls of government?

The Threat Spectrum

Earth’s orbit, home to GNSS satellite constellations, continues to grow increasingly crowded. According to the most recent statistics from the European Space Agency (ESA), humankind has launched about 13,630 satellites into Earth’s orbit since 1957, the beginning of the Space Age. Of those, almost 9,000 still remain.

While the majority are functional, more than 2,500 defunct satellites also continue to zip around in orbit. They have become nothing more than very large pieces of debris, which may break up, explode, collide or be involved in an event that results in fragmentation. 

Such mayhem has already occurred. The first documented case of the destruction of an operational satellite after a collision with a defunct satellite happened in early 2009. In that case, an inactive Russian military communications satellite destroyed an American Iridium 33 communications satellite. The impact blew both satellites apart. The ESA estimates more than 630 of the currently defunct satellites in orbit may be involved in similar events.

Add this to an environment already littered with hunks of other dangerous junk. The space surveillance networks regularly catalog and track 36,500 objects of debris larger than 4 inches across. But not all objects are tracked. Based on statistical models, ESA estimates there are 1 million chunks of space debris from 0.4 inches to 4 inches and 130 million from .04 to 0.4 inches. The total mass of this space garbage is estimated to weigh in at more than 10,000 tons.

The problem will continue to get worse. Computer simulations project that space trash between 4 and 8 inches may multiply 3.2 times over the next 200 years. These same models predict debris less than 4 inches will increase even more, by a factor of 13 to 20.

This raises serious concerns for PNT resilience. While the danger of satellite-to-satellite impacts may be obvious, even a tiny fragment of debris in space can cause catastrophic damage to satellites. These objects often travel faster than a speeding bullet, at speeds of more than 22,300 miles per hour. This can lead to satellite destruction and result in fragmentation. 

Growing orbital congestion also increases the risk of unintentional radio frequency interference.

For these reasons, the costs of mitigating space debris continue to add up. In addition to costs associated with tracking it, companies and governments pay a hefty price for design measures, dodging space debris in orbit or scrubbing missions entirely. Considering a GPS III satellite costs $400 million or more to build, an ounce of prevention may be worth the potential financial losses of a collision.

A Big Cluster

From a policy standpoint, space debris remains an unsolved global issue. Space law consists primarily of international agreements, treaties, conventions, and United Nations General Assembly resolutions and rules and regulations of international organizations. None of these explicitly forbid the production of space debris. They also don’t indicate who is responsible for removing it.

For example, the 1967 Outer Space Treaty imposes general responsibilities on member states for national activities to ensure they are conducted in conformity with the treaty (with the premise of freedom for exploration by all), to authorize and continually supervise its activities, and to share international responsibility for activities in which the state is a participant. Article VIII provides that a state “shall retain jurisdiction” and control over its objects. Most interpret this as including debris. Thus, states and organizations make their own rules for dealing with debris.

In the United States, just this July, the White House Office of Science and Technology Policy released the National Orbital Debris Mitigation Plan to meet space sustainability priorities to mitigate, track and remediate debris. This new 14-page plan supports the overarching 2021 U.S. Space Priorities Framework and implements Space Policy Directive-3 (SPD-3).

Signed by former President Trump, SPD-3 was the nation’s first National Space Traffic Management Policy. It outlined key roles and responsibilities. The directive assigned the administrator of NASA as lead for efforts to update the U.S.’ Orbital Debris Mitigation Standard Practices and to establish new guidelines for satellite design and operation to mitigate the effect of orbital debris on space activities.

NASA, the directive indicated, must do this in coordination with the secretaries of state, defense, commerce and transportation, and the director of national intelligence. In contrast to this coordination requirement, according to the directive, the NASA administrator must consult with the FCC chairman.

SPD-3 requires the secretaries of commerce and transportation to assess the suitability of incorporating these updated standards and best practices into their respective licensing processes—again, in consultation with the FCC chairman. In short, the FCC has an important, but consultative, role when it comes to space debris—at least for U.S. government agencies.

In 2019, NASA updated The United States Government (USG) Orbital Debris Mitigation Standard Practices (ODMSP), originally established in 2001 to address the increase in orbital debris in the near-Earth space environment. These updated standard practices for the feds included preferred disposal options for immediate removal of structures from the near-Earth space environment, a low-risk geosynchronous Earth orbit (GEO) transfer disposal option, a long-term reentry option, and improved move-away-and-stay-away storage options in medium Earth orbit (MEO) and above GEO. 

But when it comes to commercial use of space, the FCC holds the keys to the kingdom in terms of licensing. Even so, generally speaking, agencies coordinate across the aisle when creating policies that could impact each other. Imagine the surprise when in August the FCC announced a proceeding on Space Innovation; Facilitating Capabilities for In-space Servicing, Assembly, and Manufacturing (ISAM).” As defined in this Notice of Inquiry (NOI), the FCC defines missions in its purview as those “which can include satellite refueling, inspecting and repairing in-orbit spacecraft, capturing and removing debris (emphasis added), and transforming materials through manufacturing while in space.” 

Playing Nice in the Space Box

An FCC NOI is a way to ask the public to comment on specific questions about an issue to help determine whether further action is warranted. NOIs are the precursor to the agency’s Notice of Public Rulemaking (NPRM).

In this most recent NOI, the FCC specifically seeks comment on “space safety issues that may be implicated by ISAM activities, including orbital debris considerations.” 

This is not the commission’s first foray into space debris regulation. It has been reviewing the orbital debris mitigation plans of non-Federal satellites and systems for more than 20 years as part of its licensing and grants for space systems. The commission asserts its authority to regulate orbital debris derives from the Communications Act of 1934, as amended, which provides this authority to license radio frequency uses by satellites. 

In 2000, for example, it adopted rules requiring disclosure of plans to mitigate orbital debris for licensees in the 2 GHz mobile-satellite service. Those were the basis for rules applicable to all services that were adopted shortly thereafter (Establishment of Policies and Service Rules for Mobile Satellite Service in the 2 GHz Band, Report and Order, 15 FCC Rcd 16127, 16187-88, paras. 135-138). In 2004, it adopted a comprehensive set of rules on orbital debris mitigation (2004 Orbital Debris Order, 19 FCC Rcd at 11575, para. 14).

Just two years ago, it held an orbital debris proceeding, Mitigation of Orbital Debris in the New Space Age. It sought public comment on a variety of areas for rule updates, including an “active debris removal” as a debris mitigation strategy for planned proximity operations. While it concluded more detailed regulations would be premature, the resultant report nevertheless updated the commission’s satellite rules on orbital debris mitigation for the first time in more than 15 years. 

The 2020 FCC rule changes included “requiring that satellite applicants assign numerical values to collision risk, probability of successful post-mission disposal, and casualty risk associated with those satellites that will re-enter earth’s atmosphere.” Among other things, the rule changes also levied new disclosure requirements on satellite applicants related to protecting inhabitable spacecraft, maneuverability, use of deployment devices, release of persistent liquids, proximity operations, trackability and identification, and information sharing for situational awareness. 

And yet, others in the interagency balk at what some have referred to as the FCC’s continued stretching of its legal limits. The 2020 rule changes apparently stirred up considerable debate and controversy. Despite objections from the Department of Defense and other government agencies, the FCC pressed ahead. 

PNT Industry Impacts?

Fast forward to today. Comments on the FCC’s latest space-based regs focused on ISAM issues are due 45 days following publication in the Federal Register (August 5). Here is the list of topics for which the commission seeks comment. (Note the commission includes space debris as part of ISAM for purposes of this drill):

Spectrum Needs and Relevant Allocation: 
The variety of radiofrequency communications links that could be involved in ISAM missions. 

Licensing Processes in General: Any updates or modifications to the commission’s licensing rules and processes that would facilitate ISAM capabilities. 

Satellite Servicing Missions: Any additional licensing considerations unique to satellite servicing missions including servicing missions consisting of multiple spacecraft. 

Assembly, Manufacturing and Other Activities: Any special considerations in licensing of assembly and manufacturing missions. 

International Considerations: Whether and how to take into account that ISAM missions also raise the possibility of interactions between operators under the jurisdiction of multiple nations in the commission’s licensing process. 

Orbital Debris Mitigation: The implications of updated practices and approaches to stored energy and potential byproducts from in-space assembly. 

Orbital Debris Remediation: Whether and how the commission should consider active debris removal as part of an operator’s orbital debris strategy. 

Activities Beyond Earth’s Orbit: Any updates to the commission’s rules that might facilitate licensing ISAM missions beyond Earth’s orbit, including missions to the Moon and asteroids. 

Encouraging Innovation and Investments in ISAM: Ways to facilitate development of and competition in ISAM activities, provide a diversity of on-orbit service options and promote innovation and investment in the ISAM field. 

Digital Equity and Inclusion: How the topics discussed and any related proposals may promote or inhibit advances in diversity, equity, inclusion and accessibility, as well as the scope of the commission’s relevant legal authority.

Insofar as all commercial satellites may be affected by this proposal, the PNT community should engage. Will this latest FCC foray into potential space debris rulemaking protect, or lay waste to, the industry’s chances of reaching the space-high projected valuation of $8,817.3 million by 2031? Only time..and space…will tell. 

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