GPS World

Tag: complementary PNT

  • FCC opens door to GPS alternatives, but risks undermining its greatest strength

    FCC opens door to GPS alternatives, but risks undermining its greatest strength

    On March 27, the Federal Communications Commission (FCC) unanimously approved a Notice of Inquiry (NOI) to explore GPS alternatives, amid escalating threats to security and system resiliency. The move signals growing federal concern about the reliability of space-based navigation and timing infrastructure amid rising global interference and spoofing incidents.

    But while the FCC’s broad consideration of alternative technologies is a welcome step forward, its framing also risks weakening one of GPS’s most important defenses: the growing adoption of multi-constellation strategies across the commercial sector.

    Rising Threats, Broader Mandates

    The FCC’s decision follows the release of the International Air Transport Association’s (IATA) latest safety report, which documented a 175% increase in GPS interference and a 500% rise in spoofing attacks year-over-year. These incidents pose critical challenges to aviation safety, emergency services, telecommunications, and countless other sectors that rely on Positioning, Navigation, and Timing (PNT) services.

    Against this backdrop, the Commission’s vote reflects a bipartisan sense of urgency. The NOI invites public comment on a range of technologies that could serve as complements or alternatives to GPS, including low-Earth orbit (LEO) satellites, terrestrial signals, and enhanced end-user devices. This broad framing is encouraging and acknowledges the multifaceted nature of PNT resilience.

    A Multi-Layered Approach to PNT

    The FCC’s focus on diversification — across space-based, terrestrial, and user-level technologies — is not only prudent, but essential. Enhancing national security and system redundancy requires more than a single backup solution. It demands layered resiliency that integrates complementary modalities into a cohesive ecosystem.

    It is very encouraging that the NOI outlines a wide array of candidate technologies that could play a role in improving the U.S. PNT infrastructure. These range from inertial navigation systems and time transfer services to novel terrestrial radio signals and commercial LEO constellations. By casting a wide net, the FCC opens the door to innovation and allows market forces to contribute meaningfully to PNT modernization.

    Commercial Reality vs. Government Narrative

    However, the FCC’s discussion notably underplays a key reality: few commercial technologies today rely solely on GPS. The commercial PNT landscape has already moved beyond single-source dependency, with the vast majority of systems integrating multiple GNSS constellations (such as GPS, Galileo, BeiDou and GLONASS) alongside additional sensor and signal data to ensure robust coverage and accuracy.

    This multi-constellation approach is arguably the single most powerful tool we have to strengthen the resilience of GPS-dependent systems. By allowing receivers to pull data from multiple GNSS sources, users gain spatial and signal diversity, enabling them to cross-check signals, reject spoofed or erroneous data, and maintain accurate position and timing even in degraded environments. It’s important to remember that a device can’t selectively use GNSS networks depending on the user’s geography. If U.S. device makers disable BeiDou and GLONASS, then anywhere in the world that receiver goes it will be less performant and competitive. In recent field tests, we found that disabling the BeiDou constellation decreased a device’s positioning accuracy by 30% to 40%.

    This accuracy and resilience are especially important in sectors like aviation, autonomous systems, and emergency response, where signal fidelity and redundancy can be life-saving. Multi-constellation GNSS use isn’t theoretical: it’s already the industry standard.

    The International Tightrope

    Despite this, key elements of the NOI, as well as comments during the meeting, reflect a growing U.S. government skepticism toward the inclusion of foreign GNSS systems, especially BeiDou and GLONASS. While geopolitical caution is understandable, overly rigid restrictions on international signals could do more harm than good.

    These systems are not merely foreign-owned alternatives. They are integral components of the modern GNSS environment. Many U.S. commercial devices — ranging from smartphones to augmented reality, fleet tracking systems, drones, and more — already leverage multiple GNSS sources by default. Future technologies such as autonomous vehicles, robotics and urban air mobility will also require multiple GNSS signals to function. Prohibiting or restricting their use could mean rolling back years of progress in signal resilience, not to mention stymying future technologies, and all for a speculative and largely unquantified national security risk.

    While there are some valid concerns about adversarial control over PNT infrastructure, the FCC must weigh these carefully against the real, measurable benefits of an open and interoperable GNSS ecosystem. An overcorrection risks introducing new vulnerabilities in the name of mitigating others. In reality, the more vulnerable elements of the threat surface are GNSS receivers and mobile networks, particularly 5G systems, where user location is actually determined and tracked. Unlike the largely speculative and technically unproven threats tied to adversarial GNSS constellations, there are well-documented cases of compromised receivers and nation-state exploitation of mobile infrastructure – the very reason several countries have banned Chinese 5G providers. The FCC should focus on these clear and active risks, rather than reacting to theoretical scenarios that experts argue are not technically feasible.

    Innovation at Risk

    There is a significant opportunity at this moment. The NOI rightly identifies emerging technologies that can enhance U.S. resiliency, including advanced chipsets, LEO-based positioning, crowd-sourced signal verification, and next-generation timekeeping tools.

    However, that innovation cannot thrive in isolation. If the U.S. limits the ability of domestic systems to take full advantage of all available GNSS sources, it will undermine both resiliency and competitiveness. Even worse, it could widen the gap with foreign alternatives, especially China’s BeiDou system, which is already surpassing GPS in both accuracy and global coverage. GNSS has always thrived on multi-national cooperation and the opportunity of soft power influence. Both of which are diminished by exclusion, which is likely why there have not been bans by other countries to date.

    A Path Forward

    The FCC is right to prioritize this issue. It is urgent for the U.S. to build a more robust and secure PNT infrastructure in the face of these mounting threats. But its long-term success will depend on whether or not it embraces the full complexity of the PNT landscape.

    This means supporting:

    • Open, multi-constellation GNSS access for commercial users.
    • A flexible, layered approach that integrates space, terrestrial, and user-level technologies.
    • Public-private collaboration to accelerate innovation and deployment.
    • Clear regulatory guidance that balances national security concerns with commercial realities.

    The future of secure and reliable PNT lies not in isolating GPS, but in augmenting it through interoperability, diversity, and resilience at every layer of the system.

    If the FCC’s inquiry can steer the country in that direction, it will be a pivotal moment not just for GPS, but for the entire space-based infrastructure upon which modern life depends.

  • NextNav proposes a GPS complement and backup in the lower 900 MHz band

    NextNav proposes a GPS complement and backup in the lower 900 MHz band

    A year after NextNav shared a new vision for the Lower 900 MHz band, the Federal Communications Commission (FCC) collected additional comments seeking to bolster positioning, navigation and timing (PNT) resilience by exploring terrestrial and space-based technologies, including NextNav’s, that could complement and back up GPS. The FCC’s PNT Notice of Inquiry (NOI) is a level set on PNT issues, and seeks to engage stakeholders across government and industry to advance a “whole-of-government approach” to building resiliency to safeguard America’s critical infrastructure, national security and public safety.

    We caught up with NextNav’s Vice President of Regulatory Affairs, Renee Gregory, to hear more about how the company is thinking about a terrestrial complement and backup to GPS. Its technology is one of the solutions being discussed within the FCC and the broader industry.

    Why is it important to create a complement and backup to GPS? 

    Renee Gregory: GPS is an incredible technology that underpins national security, public safety and American commerce. However, GPS signals have physical limitations indoors and in urban canyons (i.e. big cities), plus the signals are vulnerable to intentional spoofing, jamming and unintentional interference. With GPS contributing more than $1 trillion to the U.S. economy since its inception, and a potential outage costing $1.6 billion per day, relying on a single system leaves us exposed. As Rear Admiral USN (ret.) David Simpson recently wrote, “If GPS goes down, critical infrastructure fails and our nation plunges into chaos.”

    What is the Federal Government doing about the problem?

    Gregory: Leaders, from President Donald Trump to Chairman Ted Cruz and Senator Ed Markey, have all advocated for the government to take action to ensure that a resilient PNT system of systems is in place. During President Trump’s first term, he signed an Executive Order establishing a comprehensive national policy to promote the responsible use of PNT services to strengthen critical infrastructure resilience. Earlier this year, the FCC adopted a NOI to promote the development of PNT technologies and solutions. It marked an important acknowledgment by the FCC of the seriousness of GPS vulnerabilities and limitations. It also reinforced the need for a system-of-systems approach that includes terrestrial PNT.

    What should our readers know about the NOI?

    Gregory: NextNav fully supports the FCC’s focus on resilient PNT. The FCC’s stated goal in the NOI is to build a record on specific actions the FCC can take to incentivize and support industry efforts to develop resilient and secure PNT technologies and solutions. The FCC intends to focus its efforts on utilizing its authority over non-Federal use of spectrum to rapidly support PNT solutions that could serve as complements or backups to GPS. NextNav has urged the FCC to enable at least one future-proof option that relies on market forces to deliver a terrestrial, wide-scale PNT solution that is broadly available to critical infrastructure, public safety, and consumers, and has a clear path to incorporation in consumer devices, like the smartphones we all use every day.

    What is the solution NextNav is proposing?

    Gregory: NextNav has a proven track record of providing accurate, reliable vertical location information to support first responders. Building on that legacy, NextNav’s next-generation 5G-based 3D PNT solution will leverage preexisting 5G networks and network capabilities, as well as the established and vibrant 5G device ecosystem, to enable a broadly available, widescale terrestrial complement and backup to GPS in partnership with one or more mobile network operators with experience in deploying newly-available spectrum and services within a relatively short period of time. This partnership model will rely on market forces and not taxpayer funding. NextNav brings not only its expertise in PNT technology but also its extensive spectrum licenses in the Lower 900 MHz band to address the critical need for resilient PNT.

    What are other technologies under consideration in the NOI?

    Gregory: The FCC is considering a range of terrestrial and space-based technologies as part of a system-of-systems approach to resilient PNT. Because different technologies and deployment models bring different strengths — and different weaknesses — truly resilient PNT requires multiple layers of redundancy and both space and terrestrial-based technologies. There is no single solution. We need an all-of-the-above approach.

    Is NextNav trying to replace GPS? 

    Gregory: No. NextNav’s efforts to develop a complement and backup to GPS will not diminish the role of GPS, which will remain vital to national and economic security.

    Is NextNav asking for new spectrum to enable its terrestrial PNT solution?

    Gregory: Some opponents have suggested that NextNav is asking the FCC to give it 15 megahertz of spectrum, but that’s simply not true. After acquiring extensive spectrum licenses at auction and in the secondary market, NextNav is the largest licensee in the lower 900 MHz band and is one of only two active geographic license holders in that band, which is today dedicated to terrestrial positioning services. In 2024, NextNav reached a commercial agreement to acquire the remainder of the licenses from the only other active geographic licensee in the band.

    NextNav is suggesting a reconfiguration of the existing licensing scheme to ensure that the lower 900 MHz band can support next-generation 5G-based 3D PNT solutions that require multiple 5 MHz blocks of spectrum, for a total of one more megahertz than the amount of spectrum currently dedicated for geographically-licensed terrestrial positioning services. To enable this band configuration, and the availability of a terrestrial PNT complement and backup, NextNav has proposed a “swap” in which NextNav will return all its current and pending license holdings in exchange for a 15 MHz nationwide license, consistent with the technical characteristics of 5G networks.

    How much does this plan cost?

    Gregory: The market-based NextNav solution will not require any taxpayer funding or legislation.

    What about those opposed to NextNav’s proposal? 

    Gregory: NextNav is focused on solving an urgent national security problem by enabling a complement and backup to GPS to advance resilient PNT. While some parties have raised objections based on claims of interference to current uses of the Lower 900 MHz band, they have not provided detailed technical analyses to support their claims that NextNav would interfere with their operations, or offered solutions beyond suggesting that the FCC reject NextNav’s proposal. Simply opposing one proposal without offering credible, fact-based solutions undermines the FCC’s goal of building a resilient, system-of-systems approach. 

    As a leader in PNT innovation, NextNav is looking forward to working closely with the Chairman, Commissioners and broader stakeholder community to accelerate the deployment of resilient PNT, building important redundancies into a system we rely on every day. 

  • Balboa Geo demonstrates PNT system in GPS-denied environments

    Balboa Geo demonstrates PNT system in GPS-denied environments

    Balboa Geo, in partnership with the Texas A&M Engineering Extension Service (TEEX) and the George H.W. Bush Combat Development Complex (BCDC), completed a rigorous field testing campaign of its POINTER system, a “dual-use,” real-time alternative positioning, navigation and timing (A-PNT) technology designed for GPS-denied, degraded and disrupted environments, including indoor, subterranean and obstructed urban settings.

    The POINTER field test plan, led by Balboa Geo’s Andrew Aubrey, Ph.D., with technical support from TEEX and Texas A&M Professor Stacey Lyle, Ph.D., RPLS, involved 130 tests across seven challenging testing and training venues located at TEEX and the BCDC.

    Test venues included:

    • A three-story concrete structure with 10-inch-thick, rebar-reinforced concrete walls
    • A compartmentalized steel-hulled ship with three decks reaching approximately 25 ft high
    • A steel shipping container (CONEX)
    • A simulated collapsed structure and rubble pile composed of steel, concrete, and a 90° tunnel network
    • A simulated industrial oil refinery with processing equipment and complex, elevated steel piping
    • A six-story steel training tower with metallic siding throughout
    • The BCDC military-grade subterranean tunnel network, featuring a main tunnel at about 10 ft deep and a heavily shielded segment with Faraday cage properties simulating greater depth

    Rigorous test design and real-time A-PNT data collection

    The POINTER field test plan deployed a Base Station Laptop (BX) and a single Transmitter (TX) emitting an omni-directional Magneto-Quasistatic (MQS) field outside each venue. Two Receivers (RX) were introduced at various internal locations to capture multiple “XYZ” axis measurements within each GPS-denied setting. Tests were repeated to validate reproducibility, with highly precise measurements taken where possible for ground truth position references.

    The BCDC military-grade tunnel network testing consisted of “normal” and “inverted” configurations. The “inverted” test consisted of placing the TX at depth within the tunnel network, with the BX and RX units located externally.

    Highlights of the summary results and key findings:

    • MQS field penetration and position location were achieved at all seven test venues.
    • Real-time, three-dimensional distance measurements were obtained for all 130 tests.
    • The mean positional uncertainty across all venues was 12.62 cm.
    • Positional uncertainty ranged from 2.5 cm to 36 cm, depending on venue complexity, receiver location, and transmitter-receiver distance.
    • Vertical measurements at the concrete structure showed uncertainties as low as 2.5 centimeters at a distance of about 11 m, and up to 24 cm at about 30 m.
    • The POINTER system demonstrated penetration into and out of the BCDC military-grade tunnel network, including the shielded portion, indicating flexibility and performance in challenging subterranean environments.
  • Q-CTRL demonstrates quantum navigation system as GPS backup

    Q-CTRL demonstrates quantum navigation system as GPS backup

    A team of researchers at Q-CTRL, a quantum infrastructure software company based in Sydney, Australia, has completed a successful demonstration of a new quantum navigation system called Ironstone Opal. The group described the system’s operation and performance in a paper posted to the arXiv preprint server.

    GPS technology is widely used for navigation in both civilian and military vehicles and aircraft. However, the increasing reliance on GPS has highlighted its vulnerability to outages, which can leave drivers stranded, force pilots to rely on outdated methods and complicate the deployment of military assets. These concerns have driven efforts worldwide to develop robust backup systems or alternatives to GPS.

    Q-CTRL’s Ironstone Opal is designed as a backup navigation system and, according to the research team, can deliver accuracy up to 50 times greater than existing GPS backup systems in certain scenarios. The system leverages quantum sensors that are highly sensitive to variations in the Earth’s magnetic field. Because the magnetic field differs depending on geographic location, these sensors can precisely determine an object’s position by reading the field and using artificial intelligence-based software to generate geographic coordinates similar to those provided by GPS.

    The research team shared that unlike conventional systems, Ironstone Opal is passive, meaning it does not emit signals that could be detected or jammed by adversaries. The system’s software is designed to filter out noise from vehicles or aircraft carrying the sensors, and the hardware is compact enough for installation in cars, trucks, UAVs and aircraft.

    Field trials conducted by Q-CTRL included both ground vehicles and aircraft. The results showed that Ironstone Opal outperformed a high-end inertial navigation system, a standard GPS backup, by up to 50 times in ground tests and by at least 11 times in airborne tests. These trials demonstrated the system’s ability to maintain high accuracy under a range of environmental conditions, altitudes, and maneuvers, with positioning uncertainty as low as 0.01% of the total distance traveled in the best cases.

    Q-CTRL’s approach combines proprietary quantum magnetometers with advanced denoising and map-matching software, allowing the system to detect subtle magnetic “landmarks” in the Earth’s structure. The technology is designed to be resilient, unjammable, and suitable for integration into a wide range of platforms, including autonomous vehicles and commercial aircraft.

  • FCC seeks public input to strengthen alternative PNT

    FCC seeks public input to strengthen alternative PNT

    The Federal Communications Commission (FCC) has issued a Notice of Inquiry (NOI) seeking public input on positioning, navigation and timing (PNT) systems and policies. While GPS is crucial for the United States’ economic and national security, its dependency as a single point of failure renders it vulnerable to disruption or manipulation by adversaries. Recognizing this vulnerability, leaders such as President Trump, Chairman Cruz, and Senator Markey have advocated for developing alternative systems to ensure resilient PNT capabilities.

    PNT data is integral to countless military, public safety, agricultural, and commercial activities. Given the dependence of the American economy and national security on GPS as the sole PNT source, the agency states that the U.S. government is prioritizing efforts to create robust backup systems that can safeguard essential functions in the event of GPS signal disruptions.

    The FCC’s NOI examines how the agency can foster the development of alternative and complementary PNT. It seeks feedback on various emerging PNT technologies being developed by broadcasters, wireless operators, satellite constellations and startups utilizing FCC-licensed spectrum. The inquiry also addresses tradeoffs among these technologies based on performance, scalability, geographic coverage, durability, cost and commercialization potential.

    The Commission aims to establish a comprehensive record to guide its actions in enhancing GPS resilience and promoting alternative PNT solutions. Potential measures include regulatory changes, public-private partnerships, testbeds, Innovation Zones and other initiatives.

    Two PNT-related petitions are currently under FCC consideration. NextNav has proposed allocating approximately $5 billion worth of spectrum to collaborate with telecom providers in establishing a PNT network. Meanwhile, the National Association of Broadcasters (NAB) has suggested adopting a new TV signal format capable of transmitting PNT information without requesting additional spectrum allocation. Insights from the NOI will help inform decisions on these proposals.

    The FCC’s inquiry reflects growing concerns about reliance on GPS as a single system for PNT data. By fostering alternatives like terrestrial networks or broadcast-based solutions such as NAB’s Broadcast Positioning System, the Commission seeks to strengthen national resilience against potential disruptions to critical infrastructure and services.

  • UN agencies denounce GNSS interference

    UN agencies denounce GNSS interference

    The International Telecommunications Union (ITU), International Maritime Organization (IMO) and International Civil Aviation Organization (ICAO) recently issued a joint statement urging “Protection of the Radio Navigation Satellite Service from Harmful Interference.”

    All three organizations are United Nations agencies and have previously issued similar statements independently. This is the first time they have spoken on this in one voice.

    In 2020, ICAO issued a letter to all member states urging them to “strengthen CNS systems resilience and mitigate interference to GNSS.” It contained 13 recommendations resulting from three different work streams within the organization. The last of the recommendations was “… to support the multi-disciplinary development of alternative positioning, navigation and timing (APNT) strategy and solutions to complement the use of GNSS in aviation in coordination with ICAO and airspace users.”

    In 201, IMO issued a circular on deliberate GNSS interference.. It called on nations to prevent interfering transmissions coming from their territories, issue warnings about known interference, and consider taking actions to prevent unauthorized interfering transmissions.

    ITU issued a circular on “Prevention of harmful interference to Radio Navigation Satellite Service Receivers in the 1559 – 1610 MHz frequency band” in 2022. It emphasized that, according to ITU Radio Regulations, “All stations are forbidden to carry out unnecessary transmissions, or the transmission of superfluous signals, or the transmission of false or misleading signals…”

    This ITU circular urged nations to “address the critical issue” by: 

    • Reinforcing navigation systems’ resilience to interference.
    • Increasing collaboration between radio regulatory and enforcement authorities.
    • Reinforcing civil-military coordination to address interference risks associated with RNSS testing and conflict zones.
    •  Increase coordination between aviation, military and radio-regulatory authorities.
    • Retain essential conventional navigation infrastructure for contingency support in case of RNSS outages and develop mitigation techniques for service loss.

    A resolution by ITU’s 2023 World Radiocommunications Conference echoed similar themes. Still, it was criticized because its cautions and prohibitions came with the caveat, stating “…without prejudice to the right of administrations to deny access to the RNSS, for security or defense purposes.”

    Many observers opined that there are few reasons for nations to interfere with GNSS other than security or defense concerns, which allows malicious actors to have carte blanche. Furthermore, it was suggested that the resolution might have included language to ensure that security and defense-related disruptions do not extend beyond a nation’s borders or similar provisions.

    While no specific events are cited in the statement as motivating its publication, the death on Christmas Day of thirty-nine people aboard an Azerbaijan Airlines flight could have been the reason. The aircraft was approaching a Russian airport during an intentional interference event and was apparently misidentified by Russian forces. It was subsequently damaged by ground fire and crash-landed in Kazakhstan.

    The recent joint statement cites, among other international agreements and actions, the ITU Constitution, which says, “All stations, whatever their purpose, must be established and operated in such a manner as not to cause harmful interference to the radio services or communications of other Member States.”

    The joint statement concludes with:

    Therefore, ITU, ICAO and IMO jointly and urgently call on their respective Member States to:

    • Protect the RNSS from transmissions that can adversely cause harmful interference, degrading, interrupting, or misleading signals used for civilian and humanitarian purposes.
    • Reinforce the resilience of the systems that rely on RNSS for navigation, positioning, and timing in relation to this type of interference.
    • Retain sufficient conventional navigation infrastructure for contingency support in case of RNSS outages and misleading signals, and develop mitigation techniques for loss of services.
    • Increase collaboration between radio regulatory, civil aviation, maritime, defense and enforcement authorities.
    • Report cases of harmful interference affecting RNSS to the appropriate telecommunication, aeronautical, and maritime authorities and the ITU Radiocommunications Bureau to enable the monitoring of the situation.

    The United Nations and its agencies are collaborative bodies that operate by consensus and through the cooperation of members. As such, they have no ability to enforce standards or compel compliance with recommendations.

    Read the joint statement here.

  • US Army approves production of MAPS Gen II for GPS resilience and modernization

    US Army approves production of MAPS Gen II for GPS resilience and modernization

    Project Manager Positioning, Navigation and Timing’s Mounted PNT product office has received full-rate production approval for the Mounted Assured Positioning, Navigation and Timing System Generation II (MAPS Gen II), a key Army modernization initiative, from the Program Executive Office Intelligence, Electronic Warfare and Sensors. This approval allows the Mounted PNT office, in collaboration with Collins Aerospace, to begin full-rate production and fielding of MAPS Gen II as it moves toward initial operating capability.

    MAPS Gen II provides GPS anti-spoofing and anti-jamming capabilities through sensor fusion algorithms and non-radio frequency sensors. These features enable mounted soldiers to operate in environments where military GPS is denied or degraded. The system supports U.S. Army forces by allowing them to move, shoot and communicate effectively while distributing PNT data to multiple users on a single platform. This is designed to eliminate redundant GPS receivers and antennas.

    The system includes anti-jamming and anti-spoofing protection, a sensor fusion processor that integrates multiple PNT sources, and open architectures such as APSN and VICTORY. It outputs PNT data through multiple distribution standards, ensuring compatibility across platforms.

  • US Air Force tests alternative PNT systems for GPS-denied environments

    US Air Force tests alternative PNT systems for GPS-denied environments

    The Air Force Life Cycle Management Center’s Positioning, Navigation and Timing (PNT) Program Office, Integrated Solutions for Systems (IS4S) and AEVEX Aerospace have completed flight tests for the Resilient-Embedded GPS/INS (R-EGI) Modular Open Systems Architecture (MOSA). The tests demonstrated R-EGI’s ability to integrate third-party alternative PNT solutions to ensure reliable navigation in GPS-denied environments.

    This achievement marks a step forward in developing R-EGI, demonstrating its ability to integrate a “plug & play” third-party alternative PNT capability that ensures reliable navigation in GPS-denied environments.

    “This flight test represents a pivotal moment in the evolution of resilient PNT systems,” said Jeff Hebert, senior scientist for PNT at the Air Force. “The rapid and cost-effective integration of third-party PNT solutions into Department of Defense weapons systems is precisely why R-EGI and its open architecture were envisioned.”

    The R-EGI system’s open MOSA design enables seamless integration of government and third-party applications to address emerging navigation threats. Its Mission Capability Navigation (MCNAV) component allows for seamless integration of external alternative PNT solutions under challenging conditions.

    During six test flights on a Special Operations Command C-146A Cougar aircraft, R-EGI operated successfully in GPS-denied environments, validating the system’s resilience and capacity for real-time adaptability. Using AEVEX Aerospace’s LynxVBN vision-based navigation system, it maintained approximately 10 m of positioning accuracy for up to 2.5 hours. Notably, LynxVBN was integrated into R-EGI’s MCNAV software in just one hour, underscoring the system’s adaptability. As the algorithms continue to improve and evolve, R-EGI’s alternative PNT accuracy will only become more refined, enhancing its capability to perform in increasingly complex and challenging environments, according to the company.

    “After demonstrating that the R-EGI architecture could integrate multiple GPS receiver vendors, and then three months later, witnessing its performance, from the Cougar-provided live-stream data feed, in real-time GPS-denied flight scenarios was the most impressive showcase we’ve seen in the program’s history,” said Major Bernard Mutz, project manager for R-EGI

    The successful integration of alternative PNT technologies into R-EGI seeks to enhance the system’s GPS resilience. Also, it sets a new benchmark for reliable, flexible navigation in GPS-degraded environments, said Mikel Miller, senior vice president for PNT at IS4S.

  • FCC to Meet on GPS Alternatives

    FCC to Meet on GPS Alternatives

    Federal Communications Commission (FCC) Chair, Brendan Carr announced in a March 5 blog post that the commission would be addressing GPS alternatives along with Next Generation 911 issues at its next meeting.

    Pledging that “…public safety and national security will be top priorities for us at the FCC” along with quick action on related issues, Chairman Carr said the commission’s March 2025 open meeting will start “… with an inquiry that explores alternatives to GPS.”

    Describing GPS as indispensable but not infallible, Carr’s post showed a substantial appreciation of PNT and GPS alternative issues as well as much of the related policy history.

    It also cites President Trump, Senator Cruz, and Senator Markey as advocating action to “… ensure we have a resilient system in place.”

    In 2020, President Trump issued Executive Order 13905 on “Strengthening National Resilience Through Responsible Use of Positioning, Navigation, and Timing Services.” Designed to stimulate adoption of open market commercial solutions, it does not seem to have made the nation’s PNT substantially more resilient in the intervening five years. This may be because GPS is free and time and navigation have been provided by the government as free utilities for hundreds of years. Also, many GPS users may be unsure about the need for alternatives since the federal government has not yet acted to protect itself with an alternative system. Potential users are also reluctant to purchase commercial PNT services as they are unsure which commercial services will have the longevity to make the cost and effort of adoption and integration worthwhile.

    President Trump also supported the need for GPS alternatives in Space Policy Directive 7, “The United States Space-Based Positioning, Navigation, and Timing Policy.” It called for the government to “…identify and implement, as appropriate, alternative sources of PNT for critical infrastructure, key resources, and mission-essential functions.”  This directive was issued shortly before the end of the first Trump administration and, though the directive still stands, this provision has not yet been acted upon.

    Carr’s mention of Senators Cruz and Markey undoubtedly refers to their joint sponsorship of the National Timing Resilience and Security Act of 2018. The act called for the Department of Transportation to ensure establishment of at least one terrestrial timing system as a backup for GPS signals. The first Trump administration and the Biden administration never requested funding for such an effort, so the mandate has yet to be implemented.

    Regarding GPS alternatives Carr’s post also says “…it is important that we catch up to other countries that are looking at robust alternatives of their own.” This is likely a reference to a memo ADM Allen, the chair of the National Space-based Positioning, Navigation and Timing Advisory Board, sent to the deputy secretaries of Defense and Transportation in July of last year. It warns about the U.S. falling behind in PNT, especially compared to China.

    An FCC meeting on GPS alternatives is also timely as the commission has received two petitions related to provision of nation-wide PNT services. One is from NextNav, seeking spectrum to underwrite its proposal to work with telecom providers. The other is from the National Association of Broadcasters (NAB), asking to mandate and accelerate implementation of the new ATSC 3.0 television broadcast format. NAB says its Broadcast Positioning System signals will be included as part of that format.

    While GPS alternatives will be discussed at the upcoming meeting, no decisions on systems is contemplated. Carr says the commission:

     “… will vote on an inquiry to explore other Positioning, Navigation, and Timing (PNT) systems that can be complements or alternatives to GPS. Beyond answering technical questions, we hope this effort will engage stakeholders across government and industry to encourage the development of new PNT technologies and solutions.”

    On March 6, the commission released a fact sheet with an attached draft Notice of Inquiry (NOI). The 24-page draft seeks public input on a wide variety of PNT policy and technical issues. The NOI is intended to:

    • Discuss current PNT technologies and efforts, both from governmental and private sector entities, for developing complementary and resilient PNT technologies.
    • Seek comment on various space-based solutions for resiliency of PNT, such as medium Earth orbit (MEO) satellite systems and low Earth orbit (LEO) satellite systems.
    • Seek comment on various terrestrial solutions for resiliency of PNT, such as leveraging TV broadcast infrastructure, ground-based transmitters, and/or user equipment positioning.
    • For all technologies, ask commenters for information on the benefits and challenges of particular PNT technologies or solutions based on factors such as: geographic coverage; availability of existing equipment; use of spectrum resources; the extent to which the technology should be viewed as a complement to or substitute for GPS and other PNT technologies; performance characteristics such as range and precision; durability; international considerations; and the cost and incentives to develop, deploy, and maintain the technology or solution.
    • Seek comment on additional actions that the Commission could take to facilitate the security of PNT technologies available to consumers.
    • Seek comment on whether to amend the Commission’s existing rules or adopt new rules to promote adoption of complementary and alternative PNT technologies.
    • Ask questions about what role public-private partnerships, testbeds, or Innovation Zones may play to test and develop PNT technologies.

    The FCC open meeting’s agenda also includes two items about 911 services. One of those is “Strengthening 911 Location Accuracy Rules” especially for the vertical (z) axis. This seems to be a separate and distinct issue from the PNT agenda item with the burden of performance and response placed on telecom providers. That said, some eventual linkage cannot be entirely discounted.

    The meeting will take place on March 27 from 10:30 to 12:30 EDT. A formal agenda will be posted approximately a week in advance. The meeting can be live streamed at https://www.fcc.gov/March2025 and a recording will be available on YouTube shortly thereafter.

  • Slingshot Aerospace advances GPS jamming detection for military intelligence and security

    Slingshot Aerospace advances GPS jamming detection for military intelligence and security

    The U.S. Space Force’s Space Systems Command (SSC) has awarded a $1.9 million contract to Slingshot Aerospace to enhance its GPS jamming and spoofing detection capabilities. This contract, Positioning, Navigation and Timing – Secure Electronic Navigation Threat Intelligence and Location (PNT-SENTINEL), aims to improve the company’s existing technology by incorporating advanced artificial intelligence and predictive analytics.

    The PNT-SENTINEL program builds upon Slingshot’s previous work under the Data Exploitation and Enhanced Processing (DEEP) contract, awarded in October 2021. The technology developed through DEEP currently assists the U.S. Space Force in detecting GPS jamming and ground-based interference sources related to ongoing conflicts, potential future conflict zones and counterterrorism efforts.

    GPS spoofing and jamming pose significant threats to both military operations and civilian infrastructure. Such interference can impact a wide range of operations, including satellite systems, ground and air operations and critical services such as commercial airline operations and vehicle navigation. The global reliance on GNSS has increased the importance of protecting these signals from interference.

    Slingshot’s technology utilizes a mesh network of thousands of satellites to create a near-real-time picture of GPS jamming occurrences worldwide. This space-based approach offers a more comprehensive view of global jamming conditions compared to traditional ground-based detection systems.

    As part of the contract, Slingshot will integrate its AI model, Agatha, into the PNT-SENTINEL system. This integration aims to enhance the technology’s ability to detect and differentiate between unintentional interference and deliberate jamming or spoofing attempts. The improved system will also implement pattern recognition algorithms to identify active jamming events and predict how situations may evolve.

    The contract also includes provisions for expanding the system’s capabilities to monitor interference across multiple GNSS sources, not just GPS. This multi-GNSS processing will allow for a more complete, real-time view of jamming activities by incorporating data from allied nations’ spacecraft.

    The PNT-SENTINEL system is designed to be interoperable with existing military systems, enabling near-real-time information dissemination to support rapid decision-making in national security operations. These enhancements aim to provide warfighters with a strategic advantage in GPS-contested environments.

  • Australia and India advance resilient PNT

    Australia and India advance resilient PNT

    Skykraft, an Australian space technology company, has signed a participating project partner agreement to advance positioning, navigation and timing (PNT) systems in low-Earth orbit (LEO). This agreement, backed by an International Space Investment (ISI) India Projects grant from the Australian Government, marks a significant milestone in fostering space cooperation between Australia and India.

    The project’s primary objective is to develop and demonstrate collaborative PNT systems. This includes establishing the viability of large-scale LEO constellations, addressing vulnerabilities in existing GNSS in denied environments, and exploring novel applications for PNT signals from LEO. Additionally, the project aims to create a comprehensive roadmap for collaborative LEO-PNT by implementing resilient, easily updatable constellations.

    The project also seeks to enhance environmental monitoring capabilities through GNSS-reflectometry (GNSS-R) and radio occultation (GNSS-RO) technologies. This will improve understanding of Earth’s oceans, droughts, and floods while enhancing real-time space and terrestrial weather forecasting. It will explore emerging applications, such as tsunami monitoring and warning systems.

  • Honeywell unveils resilient EGI for GPS-denied environments

    Honeywell unveils resilient EGI for GPS-denied environments

    Honeywell has unveiled its resilient embedded GPS/inertial navigation system (EGI), designed to address the evolving challenges of modern warfare and meet U.S. government mandates for greater power competition. This navigation system integrates GPS and inertial navigation technologies to deliver precise position, velocity and timing information for various applications.

    Expanding on Honeywell’s H-764 and FALCN, the EGI is specifically designed to fulfill military needs in areas where GPS jamming and spoofing are prominent. The system includes M-code capability, an atomic clock and open architecture compliance, allowing crucial mission flexibility with alternative positioning, navigation and timing (PNT) forms.

    It allows for the seamless integration of various alternative PNT sources, including vision navigation, celestial navigation and magnetic navigation for continuous and accurate navigation even in the face of GPS threats.

    Honeywell plans to make engineering units of this EGI available in early 2026, with certifiable units following shortly after. The company said this timeline allows for thorough testing and refinement, ensuring the system meets the reliability and performance required for critical military applications.