The New York Times described it as “a stunning example of the global economy’s fragile dependence on certain software, and the cascading effect it can have when things go wrong.”

Regular readers of this magazine, and of this column in particular, will know where I am going with this: like Windows, GPS — and, more broadly, GNSS — presents a single point of failure for many systems. That is, if GPS fails, it will stop those entire systems from working.

Possible challenges and threats to GPS use include space weather; interference/jamming and/or spoofing of receivers; error or failure of satellites, monitoring, or control; and, in the most extreme case, an attack on satellites, monitoring, or control.

The National Space-Based PNT Advisory Board continues to focus its efforts on its excellent PTA strategy: to protect (“prevent or remove conditions that degrade, distort, or deny GPS use”), toughen (“make GPS use more robust against challenges and threats”), and augment (“provision of GPS enhancements as well as provision and use of alternate [PNT] sources that complement, back up, or replace (partly or entirely) use of GPS”) civil uses of GPS. More on that soon.

Meanwhile, others are urging we think of GNSS as only one of several complementary means to achieve the mission of positioning, navigation and timing (PNT) with accuracy, availability, integrity, continuity and coverage. For that perspective, see Mitch Narins’ piece. He writes that we should focus “on services that are not space-based, operate in different areas of the spectrum, are capable of higher power, and can be installed and evolved more quickly to mitigate emerging threats.”

The European Space Agency’s recent PNT Vision 2035 paper, written by a panel of independent external PNT experts to advise next year’s ESA Ministerial Conference, summarizes European discussions on PNT in the past several years. In the words of Luis Mayo, the chair of the advisory committee that wrote the report, “there is more to PNT than satellite navigation.” While we must “sustain the existing satellite-based navigation systems,” he argues, we should also promote “the development of alternative independent PNT systems.” Read a short interview with Mayo by Dana Goward, starting on page 19.

Yet other efforts integrate GNSS with different, independent techniques to create new synergies. One example is ESA’s Genesis multi-modal space mission, which aims to improve geodetic applications by collocating on board a single well-calibrated satellite the four space-based geodetic techniques: GNSS, very long baseline interferometry (VLBI), satellite laser ranging (SLR) and Doppler Orbitography and Radio-positioning Integrated by Satellite (DORIS).

“This first-time collocation in space will establish precise and stable ties among these key techniques,” write the authors of this quarter’s “Innovation” column.

<p>The post First Fix: Global Glitch first appeared on GPS World.</p>

Image: 3DSculptor/iStock / Getty Images Plus/Getty Images

If not GNSS, then what?

An interesting question.

To some, it means GNSS is so important and unique that without it, all is lost. They enthusiastically support only GNSS-centric research and development, believing that any issues that GNSS has today — such as lack of resilience — can be resolved given enough time and money. It includes pushing for the discontinuance of ground-based systems and the “re-purposing” of their resources to produce more satellites and more space-based signals. It demonstrates an admirable and true dedication to the belief that GNSS is the mission.

To others, these words have a different and darker meaning, warning of a clear and present danger. To them, it means “When (not if) GNSS is not available, what other source(s) of positioning, navigation and timing services (PNT) will be available to support GNSS users’ missions and goals?” For these purpose-driven individuals, GNSS is a means — not the mission, which is to provide the necessary positioning, navigation and/or timing performance, such as accuracy, availability, integrity, continuity and coverage, required to ensure the nation’s safety, security and economic well-being.

Unfortunately, some who have made GNSS their mission strive to convince others that it should be their mission, too!

GNSS is magic — but only when it works. It has played and will continue to play a crucial part in advancing our knowledge and abilities and supporting diverse use cases worldwide. It should and must be supported, but not to the exclusion of everything else. Recently, the magic has failed numerous times all around the world and, as a PNT community of suppliers and users, we must know we are capable of so much more.

We also know that the vast majority of civil PNT service needs are local, not global — based in part on the population density of users and their use cases. Over the years, GNSS’ accuracy and coverage have spoiled us. We even chose to see GNSS interference events as proverbial “black swans.” At the same time, the abandoning of well-engineered, resilient local solutions in favor of a global, one-size-fits-all mentality has been appealing to many. We know this approach is fraught with danger. Throwing away perfectly acceptable, resilient local means rather than enhancing them and bringing their technology into the 21st century may, as a PNT community, be our biggest regret. In many ways we have already gone too far.

I encourage our PNT community to commit to doing more, to open up our minds to design, develop, evolve, create, install, implement and operate more resilient PNT sources and more resilient user systems for which PNT services are critical inputs — especially by focusing on services that are not space-based, operate in different areas of the spectrum, are capable of higher power, and can be installed and evolved more quickly to mitigate emerging new threats. Most importantly, we all need to accept and support the true mission of our PNT community, the “why” that drives our innovative solutions: to ensure PNT services always will be available to support our safety, security and economic well-being.

<p>The post If not GNSS, then what? first appeared on GPS World.</p>

The top screen showing the hydrogen maser and cesium clocks in an adjacent isolated room used for realization of the timescale for research purposes. Students presenting their work to the USNO and Microchip Inc., visitors. (Photo: University of Alabama, Tuscaloosa)

The University of Alabama, with the support of the National Science Foundation (NSF), has established a program unlike any other in the country. It focuses on positioning, navigation, timing, and frequency (PNTF) as its own discipline, with a special emphasis on precise timing.

The Alabama Collaborative for Contemporary Education in Precision Timing (ACCEPT) is an NSF Research Traineeship (NRT) program designed to train the next generation of graduate (master’s and Ph.D.) degree holders in PNTF.

ACCEPT provides interdisciplinary training and education for physics, engineering, mathematics and computer science majors. The school hopes to make it a graduate program eventually. Enrollees are awarded a fellowship that includes a $34,000/yr stipend.

“The ACCEPT program was created because industry and government officials told us they could never find enough people in this field,” said Adam Hauser, the program’s executive director, who is also an associate professor of physics and astronomy at the university. According to Hauser “It is the only program in the nation directly addressing a larger scale workforce development in precision timing.”

Left to right: Dr. LeClair, Dr. Hauser and Dr. Bandi founded and run the ACCEPT PNT program at University of Alabama. (Photo: University of Alabama, Tuscaloosa)

ACCEPT’s Technical Director — also billed as “Time Lord” — is Thejesh Bandi, an associate professor. He reinforces Hauser’s message about the scarcity of focused talent in the area. “This field is greying,” he says. “We need young minds who will also bring in fresh ideas.”

Hauser describes the program as “a flexible multidisciplinary course curricula that includes professional development, and real-world training with our industry and government partners.”

The program’s “interdisciplinary” nature is reflected in the ACCEPT team. In addition to physics and astronomy, faculty from mathematics, electrical and computer, civil, aerospace, and mechanical engineering, as well as the communications and higher education departments, are included.

This diversity of expertise is needed for ACCEPT’s ‘holistic education” approach founded on four pillars.

1. Industry-Directed Curriculum: First, because the goal is to supply qualified graduates to fill critical national needs in industry, the foundational curriculum is based on and will continue to evolve with input from commercial entities in the PNTF space. In addition to several government agencies and labs, the ACCEPT Advisory Board includes representatives from SpectraDynamics, Aerospace Corporation, Raytheon Technologies, Microchip Technologies, L3Harris Technologies, OEWaves, Inc, Safran S.A., Northrop Grumman Corporation and the Resilient Navigation and Timing (RNT) Foundation.
2. Sustained Industry & Community Immersion: The program’s major focus is moving beyond academia. Internships and PNTF professional community events are mandatory. Students attend the National Institute of Standards and Technology (NIST) Time and Frequency Division’s time and frequency seminar each year. In their second year, they begin attending the Institute of Navigation’s annual Precise Time and Time Interval (PTTI) meeting. As their research and professional skills mature, they are expected to progress from attendees to poster presenters and speakers.
3. Professional Development: Reinforcing preparation for moving beyond the classroom, ACCEPT trains students to “… effectively work across academic, policy, governmental and industry sectors,” according to Hauser. “They need to be able to advocate as a professional to a larger audience effectively.” This means including students in programs like the university’s Speaking Studio and Capstone Center for Student Success. Communication skills, teamwork and ethics are particular focus areas.
4. Research: Bandi’s Research Quantime Lab is hosted by Professor Patrick LeClair’s Department of Physics and Astronomy. “Research projects for ACCEPT fellows and trainees are designed in conjunction with our government and industrial partners and focus on cutting-edge innovations that solve today’s problems in currently used technologies,” Le Clair said.

The lab strongly focuses on Quantum Engineering research, though there are also opportunities in Characterization and Calibration, Networking and Synchronization, and research into Precision Devices.

Click here for more information about applying for an ACCEPT fellowship or becoming an industry partner.

<p>The post ACCEPT: University of Alabama prepping next generation of PNTF experts first appeared on GPS World.</p>

According to ESA’s website, key findings in the paper include:

• Increasing Dependence on PNT Services – particularly for consumer and autonomous solutions. Accurate timing remains a critical use case, especially in telecom and power distribution.
• Geopolitical and Technological Challenges: Rising cyber-attacks, jamming and spoofing, advancements in AI, ML and quantum computing will have significant impacts. Anticipate new regulations.
• Technological Trends Driving PNT Demand: The proliferation of connected devices (IoT), autonomous driving, advanced air mobility, smart grids and autonomous vehicles will drive the demand for resilient and robust PNT.
• System Architecture Evolution: Future PNT systems will utilize a combination of data sources, including multiple GNSS constellations, cellular networks (5G/6G), terrestrial systems, augmentation systems, and autonomous sensors. This “system of systems” approach will enhance performance and ensure independence from single points of failure.
• Emerging Technologies and Sensor Integration: Advances in space segment technologies, receiver designs and sensor integration, new signal designs, flexible payloads, advanced clocks, inter-satellite links, and higher power amplifiers are highlighted.

Luis Mayo

We spoke with Luis Mayo, NAVAC’s chair, to get his take on this seminal work.

Question: To set the stage, what is NAVAC?

Luis Mayo: NAVAC is a group of external PNT experts that ESA has assembled to provide independent advice on navigation issues, and especially for NAVISP.

Q: Where can NAVAC’s formal recommendations be found?

Mayo: We perform an assessment of the NAVISP status every two years. We provide our recommendations as a conclusion of this assessment. Beyond that, our formal recommendations are collected in documents like this white paper or in proposals for modifications or adjustments to the work plans of the programs.

Q: How does ESA leadership generally view and react to NAVAC conclusions and recommendations? Does it act upon every recommendation?

Mayo: They are generally receptive. However, we are just an advisory body, so it is up to them to take on our recommendations. They often do so and use our advice to add weight to their proposal to the Navigation Programme Board, but they do not necessarily have to.

Q: PNT Vision 2035 is a substantial document. Clearly it involved some time and effort. Why was it written? Is it something ESA requested?

Mayo: The paper was the initiative of NAVAC members to inform the ESA Ministerial Conference in 2025. These conferences take place every three years to define the roadmap for the next period. New European space programmes, extensions or redirections of existing ones, and budgets are approved at these meetings.

Q: We thought we might make a modest contribution to the definition of the future ESA navigation programmes. What, if anything, did NAVAC find surprising or unexpected about findings included in the Vision?

Mayo: I would say that we hardly found anything too unexpected or surprising. The findings are the conclusion of multiple discussions on the subject over the past few years. We have just expressed them in a more articulated way.

If anything, and from my personal perspective, I would like to highlight that this exercise helped me realize that the deployment of some of the most exciting or expected applications of PNT technologies — such as autonomous driving — depend on the development and deployment of multiple other technologies that might not be necessarily available in the mid-term.

AVAC’s first meeting in 2018. From left to right: Javier Benedicto, ESA Navigation Director, and NAVAC members Alessandra Fiumara, Peter Grognard, Giorgio Solari, Rafael Lucas Rodriguez, Pierluigi Mancini, Roger McKinlay, Stefano Debei, Nityaporn Sirikan, Bernd Eissfeller and Luis Mayo. (Photo: ESA)

Q: What are the three most important things policymakers should understand from the document?

Mayo: First is that many infrastructures or services critical to the daily lives of the citizens are dependent on PNT technology.

Second, they cannot take for granted that GPS or Galileo services will be always available, not to mention GLONASS or BeiDou. Satellite navigation systems are vulnerable and are continuously under threat. Enabling assured PNT service is a must.

And third, there is more to PNT than satellite navigation. Other complementary or alternative technologies should not be abandoned. In fact, some of those technologies might even change the way in which we have traditionally conceived satellite-based navigation.

Q: What are the most important things policymakers should do to enable the PNT needed by 2035?

Mayo: I think they have to sustain the existing satellite-based navigation systems and foster the development of new technologies and systems that improve the robustness of the services. We have done a lot so far to provide PNT services globally. When you come to think of that, it’s really wonderful what we have achieved this far. We cannot afford to lose what we have, but that has proven not to be enough. Therefore, policymakers should keep helping the development of new technologies and services that complement what we have, improve the quality of the services and ensure its continuous availability and integrity.

They should also look beyond the current service volume. Spacefaring nations should be aware of the fact that they will need this kind of technology to support future missions. Deploying systems able to provide PNT services beyond the coverage of the current GNSS is an absolute necessity to support such missions.

Q: The vision says the EU must consider no longer having access to GLONASS and BeiDou. There are a number of threats that are common to all GNSS. Why not consider loss of access to all either temporarily or permanently?

Mayo: We have not considered a completely catastrophic situation such as losing access to all GNSS in our vision. We understand that GPS, Galileo and eventually other constellations or augmentation systems will remain available and provide at least partial coverage for PNT services.

Q: The vision makes recommendations about mitigating interference, using AI and extending the GNSS service volume. What else should policy and technology decision-makers take from the document and act upon?

Mayo: We must not forget there is a clear case for investing in future PNT systems. ESA should keep up to pace with foreign competitors that seem ready to increase their expenditure in these types of problems.

They also have to be conscious that satellite-based navigation is not enough. We have to look for alternative and complementary systems to reach the level of confidence that we need on PNT solutions.

Q: Perhaps you are thinking of all the PNT systems China has deployed?

Mayo: I am really thinking about what we are not doing in Europe or in the United States. We need to build alternatives that might not have global coverage but would allow us to maintain essential PNT services running at home.

Q: Resilience seems to be an important theme in the document, but it was not the subject of a specific recommendation. Could you speak to that?

Mayo: Resilience is a pervasive theme throughout the whole document. This is a major concern. We have to find a way to build a system of systems that can deliver to the user a trustworthy PNT solution at any time.

Resilience is, today, a key consideration in PNT, and we cannot do anything but acknowledge this fact. We might not have insisted enough on the importance of this feature for future PNT systems, but policymakers must undertake any actions required to improve the resilience of the existing PNT systems and services, probably by promoting the development of alternative independent PNT systems.

Q: What else should GPS World readers know about the Vision?

Mayo: Read the document. It is not that long. Also, think that it has been written from an independent and experienced standpoint. We at NAVAC do not pretend to hold the full truth, but I believe that we have a quite comprehensive view of the matter and that this would be useful for the reader.

<p>The post PNT Vision 2035 – A must read first appeared on GPS World.</p>

In that moment, you are focused on being able to communicate with someone who can send emergency personnel to your exact location. As fast as possible. GPS plays a part in all three – communicating with someone, defining your exact location, and reaching you as fast as possible.

Photo: katifcam / iStock / Getty Images Plus / Getty Images

Timing signals from GPS satellites are critical to our communications networks, allowing callers to communicate with emergency services. This is because cell phone networks rely on GPS timing receivers to keep all their base stations perfectly synchronized, which allows mobile handsets to share limited radio spectrum more efficiently.

Location is one of the most important pieces of information on which first responders depend to provide timely emergency services. “Every minute counts” encapsulates the benefits accrued from integrating information derived from GPS signals into the emergency services infrastructure. To illustrate the importance of this information, the Federal Communications Commission’s (FCC’s) January 2024 Report and Order on location-based routing for wireless 911 calls estimates this technology will improve call time responses by up to a minute, saving nearly 14,000 lives annually. Outdated systems — still operating in many areas — use cell towers, which can be as far as 10 miles away, as a reference point
for the caller’s location to dispatch emergency services. These systems misroute more than 20 million calls annually, wasting precious minutes in locating those in need. Updating these systems will enable first responders to efficiently locate and navigate to the person in need.

It is critical that federal, state and local governments continue to fund the adoption and operation of innovative, timesaving and accurate solutions to better serve the public. Your loved ones deserve nothing less.

Coming Soon: Next Generation 911

One of the ways in which GPS is being used in emergency response systems is through Next Generation 911 (NG911), a service that makes more precise location information widely available to first responders. Once fully implemented, NG911 will provide dispatchers real-time locations derived from callers’ phones and accept text messages, videos, and photos. Why is this important? NENA: The 9-1-1 Association, estimates 80% or more calls are placed from GNSS-enabled cell phones.

More than 40 states have begun to adopt NG911, according to an April 2024 Congressional Research Service report. Most of these states are still in the early stages of implementation. Many call centers continue to use legacy systems that do not use technology optimized to save lives.

A GPS III satellite model provided by GPSIA member Lockheed Martin was on display at the NG911 Institute’s Technology Showcase this spring, reminding attendees of the important role GPS satellites play today and in future NG911-enabled emergency services.

Accessible Emergency Services Serve Everyone

To bridge this gap between adoption and full implementation of NG911, third-party groups and regulators are jumping in to make vital improvements. Organizations such as accesSOS, a non- profit started by Gabriella Wong, shed light on the need for more accessible emergency services. Wong was inspired to develop the accesSOS app after her deaf father was left unable to call for help in two emergency situations. Today, approximately 50% of 911 call centers in the United States cannot accept text messages. accesSOS allows deaf and hard of hearing individuals to quickly describe their situation through an easily navigable user interface, which is then translated into a phone call made to 911 on behalf of the person in need. accesSOS uses GPS location data collected from phones to bridge the accessibility gap between areas that are using outdated systems and individuals who are left unattended by those systems.

accesSOS’ solution, along with many other ones, were on display at NG911 Institute’s Technology Showcase, including GPSIA member Garmin’s inReach-enabled devices. This service supports more than 210 dialects and languages and is available in more than 200 countries and territories. By supporting a vast array of languages, Garmin’s inReach technology exemplifies another aspect of accessibility where regulators can take additional action — overcoming language barriers.

In the United States, it is estimated that non-English speakers face wait times of 5-10 minutes when trying to connect with emergency services in their native languages. In some emergency situations, those minutes can be the difference between life and death. Industry is leading the way by ensuring personnel at their call centers can communicate in multiple languages with people who need help, regardless of the language they may be speaking.
By continuing to promote GPS- enabled solutions such as accesSOS, NG911, and inReach, we are ensuring the safety of our communities and our loved ones. The GPS Innovation Alliance (GPSIA) is proud to support the further integration of GPS into the emergency services infrastructure by uplifting innovative research and design efforts and promoting new ideas that provide lifesaving services to users across the globe.

When Highly Accurate Location Information is Not Appropriate

While providing a highly accurate location for a caller is essential to certain types of emergency response services, such accuracy is not warranted when calls are made to 988, the Suicide and Crisis Lifeline. Since its nationwide rollout in July 2022, the Lifeline service has routed more than 9.6 million calls, texts and chats to crisis centers.

Preserving the caller’s privacy while quickly routing the call to the nearest crisis center is of the utmost importance. To preserve privacy, the caller’s precise location should not be shared. However, routing a call to a crisis center associated with the caller’s
area code — not disclosing the caller’s location — is not the answer either because the portability of mobile phone area codes has decoupled area codes from caller location. To address these shortcomings while preserving the caller’s privacy, the FCC has adopted a Second Further Notice of Proposed Rulemaking suggesting that wireless carriers route 988 calls to nearby crisis support centers using the location of the nearest cell tower, which can be located within 10 miles of the caller, rather than using a device’s location or the caller’s address.

GPS is still integral to communications between the caller and Lifeline. This case illustrates how diverse GPS-enabled technologies and solutions support a wide range of emergency response services.

If you or a loved one is experiencing a mental health crisis, please dial or text 988 to reach a crisis counselor.

<p>The post GPS is a cornerstone for emergency services first appeared on GPS World.</p>

Photo: tifonimages / iStock / Getty Images Plus / Getty Images

Describing a dangerous “asymmetric vulnerability to navigation warfare” a recent paper from the National Security Space Association (NSSA) calls for a wide variety of actions to mitigate the threat. The most important, “Focused leadership, properly empowered and resourced…”

The nineteen-page paper, in some ways, reads like a primer on GPS and positioning, navigation and timing (PNT), providing background and context for policymakers unfamiliar with the technology and the United States’ broad dependence upon it.

“Long-standing lack of progress on issues important to U.S. national, homeland, and economic security.”

The lack of focused leadership, according to the paper, is evidenced by long-standing failures to follow through on a variety of mandates from senior leadership over the course of the last 20 years. Quoting from the Federal Radio Navigation Plan, it cites persistent shortfalls in national capability as including:

• Assured, real-time PNT in physically impeded environments (e.g., indoors, urban canyons, underground facilities).
• Sufficient accuracy and integrity in electromagnetically impeded environments — including operations during spoofing, jamming, and natural and unintentional interference.
• Higher accuracy with high integrity; timely notification/alarming when PNT performance is degraded or misleading, especially for safety-of-life applications or to avoid collateral damage.
• Ensuring PNT services, including supporting information technology (IT) infrastructure and supply chain are protected from cyber threats
• Ability to accurately locate sources of intentional and unintentional interference in a timely manner.
• Insufficient resilience and survivability when GPS services are unavailable or untrusted.

“American society has been transformed by the availability of GPS.”

The paper describes four decades of GPS being incorporated into virtually every technology and used by every critical infrastructure. It calls the harm to society should it be lost “incalculable.” It also notes that the operation of many space systems that support critical infrastructure and/or critical national applications is itself dependent upon GPS for proper operation.

The military utility and advantages brought by GPS are also discussed. These include:

• Its role as the lynchpin for precision strike.
• Enabling “… the maneuver, synchronization, and massing of effects from dispersed forces.”
• PNT to achieve information and decision superiority over an adversary.

“Merely the threat of disrupting GPS services might be enough to impact U.S. national security and foreign policy.”

The paper says recent actions by and ongoing threats from adversaries of the United States are a critical concern.

Electronic warfare (EW) and cyber attacks by Russia, China, Iran, and North Korea demonstrate the ease and effectiveness of such vectors, as well as the seriousness of the threat.

As one example, Russia’s impending launch of a nuclear-armed anti-satellite weapon has the potential to both destroy or damage GPS satellites nearby and interfere with radio communications. NSSA recently published a paper on the Russian nuclear ASAT threat.

A potentially even more serious threat would be if Russia should deploy a nuclear-powered directed energy or electronic warfare weapon. Such a device would be “reusable” and could threaten an even larger number of space platforms or, in the case of an EW device, both space-based and terrestrial receivers.

“GPS blackmail”

The paper posits that the United States’ overdependence on GPS is so great that it could be subject to “GPS blackmail.” It suggests that this may already have occurred.

Prior to Russia’s invasion of Ukraine, it destroyed a defunct satellite with a ground-based missile, creating thousands of pieces of debris. Shortly thereafter, state-sponsored TV announced that Russia would destroy all 32 GPS satellites if NATO “crossed its red line.” Despite 90,000 Russian troops massing along the border, “U.S. officials decided against sending certain military equipment to Ukraine to avoid provoking Russia.”

“…could have cascading effects which unravel America’s socioeconomic fabric…”

NSSA warns that U.S. “critical infrastructures, national essential functions, and military forces could be at grave risk.” Among the impacts of a major GPS disruption, it counts:

• Loss of U.S. political prestige and influence.
• Degradation of the informational element of national power (IT and telecommunications).
• Severe socioeconomic implications. “given the integration of GPS into critical infrastructures and their interdependencies, lengthy disruption just of the power grid, for example, could have cascading effects which [would] unravel America’s socioeconomic fabric…”
• Harm to national and homeland defense. Leadership is needed to perform national essential functions.

While the paper makes several specific recommendations for actions by various departments, it also identifies national-level leadership as key:

“The United States must rapidly develop and implement a comprehensive, whole of nation, strategy to redress its asymmetric vulnerability to Navwar and restore U.S. leadership in space-based and terrestrial PNT. … Focused leadership, properly empowered and resourced, is essential to the national PNT strategy’s success.”

The NSSA paper “America’s Asymmetric Vulnerability to Navigation Warfare: Leadership and Strategic Direction Needed to Mitigate Significant Threats” was sponsored by the Resilient Navigation and Timing Foundation and can be accessed here.

<p>The post US dangerously behind, PNT leadership needed first appeared on GPS World.</p>

Photo: BrianAJackson / iStock / Getty Images Plus / Getty Images

All maritime navigators (should) know by heart Rule 5 of the 1972 Convention on the International Regulations for Preventing Collisions at Sea (Colregs for short): “Every vessel shall at all times maintain a proper lookout by sight and hearing as well as by all available means appropriate in the prevailing circumstances and conditions so as to make a full appraisal of the situation and of the risk of collision.”

Analogously, now that positioning, navigation and timing (PNT) data have become essential to the functioning of critical infrastructure and many other aspects of advanced industrial economies, it is imperative that we use “all available means” to maintain and improve that data’s accuracy, integrity, availability, continuity and coverage.

Given the inherent limitations of GNSS and the growing threat of jamming and spoofing, those means must also include other technologies, both legacy and emerging — such as L-band and S-band broadcasts from GEO and LEO satellites, fiber-optic timing systems, optical-based absolute positioning solutions, map-matching databases, inertial measuring units (IMUs), ultra-wideband and terrestrial radiofrequency (RF) technologies across low frequency (LF), medium frequency (MF), ultra-high frequency (UHF) and Wi-Fi/802.11 spectrum bands.

In March 2024, the U.S. Department of Transportation (DOT) — the lead for civil PNT requirements in the United States — released its updated Complementary PNT Action Plan: DOT Actions to Drive CPNT Adoption. It builds on Executive Order 13905, Strengthening National Resilience Through Responsible Use of Positioning, Navigation, and Timing Services; Space Policy Directive 7, The United States Space-Based Positioning, Navigation and Timing Policy; and DOT’s own 2021 report to Congress, Complementary PNT and GPS Backup Technologies Demonstration Report.

DOT’s Action Plan establishes five broad lines of effort:

1. Stakeholder engagement

2. Specs and standards development

3. Field trial and test range development

4. Establish a Federal PNT Services Clearinghouse

5. Domain-specific CPNT Services acquisition support

The plan explicitly extends the National Space-Based PNT Advisory Board’s chosen strategy of “protect, toughen, and augment” (PTA) to “protect, toughen, augment, and adopt” (PTAA).

It points out that “[s]trengths and vulnerabilities of existing complementary PNT sources can vary based on the specific application and operating environment.” For example, a ship at sea need not worry about multipath and can tolerate relatively large position errors that are unacceptable for, say, an autonomous car. The latter, however, can take advantage of nearby transmitters for ground-based solutions, as well as landmarks for self-localization. Different options for different needs.

On the last page, in a chart illustrating its “preliminary milestones and functional activities associated with implementing this action plan,” DOT lists eLoran infrastructure as one of the areas of R&D — starting with a demonstration project in the last quarter of 2023 followed by, in 2024 and 2025, “evaluate eLoran service against CPNT measures of effectiveness.”

eLoran, too. All available means.

<p>The post First Fix: By all available means first appeared on GPS World.</p>

General Atomics/AFRL X-67A in flight (Photo: Air Force Research Laboratory Public Affairs)

Little is currently known about the AFRL/GA-ASI unmanned aircraft, other than indications that it has been developed under a Collaborative Combat Aircraft (CCA) program and built on a common frame, which is intended to aid the rapid development of future new variants.

AFRL has previously sponsored Kratos to develop the XQ-58A Valkyrie, which is also intended to “work in teams with manned aircraft,” as a low-cost “attributable” asset commanded by a manned flying companion. The aircraft launches by rocket assist and is recovered vertically by parachute – the new ‘trolley’ launch capability allows the jet-powered Valkyrie to take off on a regular runway.

In earlier flight testing, communications between Valkyrie and both an F-22 Raptor and an F-35 Lightening front-line manned aircraft were established, demonstrating the manned/unmanned teaming concept. With a range of roughly 3,000 mi and an operational ceiling of 44,000 ft, the Valkyrie is intended to demonstrate how an armed, low-cost UAV can bring significant additional assets into combat situations. However, the original test article is now retired and has been put on display at the National Museum of the USAF in Dayton, Ohio, so its demonstration days appear to be over.

XQ-58A Valkyrie. (Photo: AFRL)

Nevertheless, Kratos has built several other production Valkyrie UAVs, which are reportedly undergoing tests with the US Airforce, Marines and Navy. Reports indicate that an XQ-58B electronics defense suppression version has been developed and demonstrated, along with other aircraft that have demonstrated weapons release from an internal stores bay, along with an intriguing release of a small UAV from that same internal bay.

Boeing’s Aurora Flight Sciences has just launched the Skiron-XLE Class 2 UAV – Class 2 meaning that it’s small enough to fit in the back of a pick-up truck. It was derived from an earlier Skiron-X version, which had a wingspan of 16 ft, a length of 7 ft, a weight of less than 50 lb and a meager range of only 8 mi.

Skiron-XLE. (Photo: Aurora Flight Sciences)

IE-Soar-800W fuel-cell and regulator. (Photo: IE)

Aurora has now come up with a way to extend the range of the vertical take-off and landing (VTOL) UAV by up to 47 miles and increase endurance from 3 hours to more than 5 hours. This was made possible by replacing the original battery power source on the Skiron-X with a compact hydrogen fuel-cell on the XLE supplied by Intelligent Energy (IE). The Skiron-XLE can be equipped with a gimbal mount electro-optic infrared (EO/IR) sensor and is aimed at the military/security reconnaissance role.

When fuel-cells are mentioned, some people may still think of the liquid oxygen/hydrogen sphere that blew up Apollo 13. Fortunately, however, technology has moved on significantly since this less commercial design of the 1960s. As an example, according to the company’s spec sheet, the Department of Transportation (DOT) certified IE-Soar-800W fuel-cell and hydrogen regulator offers 400 w for up to 5.9 hours. Hydrogen/oxygen gasses are combined across two semi-permeable membranes to generate power — no frozen gas-slush stirring is required.

Meanwhile, progress towards eVTOL air-taxi capability took a step forward for Archer and its Midnight aircraft. Stellantis has invested an additional $55 million into Archer’s efforts to build production capacity for up to 650 aircraft per year at its planned 350,000 sq ft facility in Georgia, scheduled to be completed in 2024.

Archer’s Midnight eVTOL. (Photo: Archer)

To clarify Stellantis’ background – the company includes manufacturers Fiat-Chrysler and Peugeot, which have merged to form the fourth largest vehicle company by sales behind Toyota, Volkswagen and Hyundai. Stellantis has a strategic funding agreement with Archer and the latest investment follows the milestone first test flight of Midnight where the successful transition from vertical lift to forward flight was achieved. The European conglomerate has also acquired up to $110 million in Archer shares on the open market and through this funding initiative.

Stellantis is working with Archer to bring its manufacturing expertise to the fabrication of Archer’s composite air taxi. High-volume car manufacturing and eVTOL building have a lot in common, and there is clearly common interest for a giant car company to gain access to the new eVTOL market.

To recap – GA-ASI has joined the CCA team with the first flight of the AFRL X-67A unmanned UAV, while Kratos continues with further testing of the Valkyrie CCA UAV with several U.S. forces. The latest generation of hydrogen fuel-cells is now extending the range and endurance of Aurora’s Skiron-XLE, while more investment flows in the eVTOL air taxi market.

<p>The post Unmanned systems updates first appeared on GPS World.</p>