GPS World

Tag: First Fix

  • First Fix: The key to unlocking GPS World

    First Fix: The key to unlocking GPS World

    Your subscription to GPS World unlocks relevant and timely coverage with unmatched print and digital design.

    GPS World strives to captivate, educate and continuously inform readers like you by focusing on technical, practical and ever-changing applications.

    For the past 36 years, our market-segmented topic areas, deep-dives, as well as broad bird’s-eye-view industry coverage is what makes it a valuable resource for professionals in every tech field.

    Your GPS World subscription offers:

    ■ The long-standing monthly print GPS World magazine

    ■ The regularly updated GPSWorld.com website, with plenty of free content and unlimited access, plus premium features available free to account holders

    ■ An interactive, downloadable and browser-based flip-through GPS World digital edition format

    ■ The breaking news and industry overview weekly Navigate! e-newsletter, conveniently delivered regularly to the email inboxes of professionals worldwide

    ■ Several market-sector e-newsletters focusing on specific topic areas such as autonomous, defense and surveying technologies

    You can update your subscription anytime. Whether you want to change your address, sign up for e-newsletters or update your contact information, all you need is your subscription account number. Rest assured, when you subscribe to GPS World, your information will never be shared or sold.

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    Keeping your information up to date will ensure you won’t miss an issue.

    Our editorial team reports on current, relevant industry topics — including the latest disruptive tech and current events affecting the industry — in print and online.

    They also cover positioning, navigation and timing (PNT) technology and developments, which work with GNSS to achieve greater accuracy, availability, integrity and robustness. These include inertial sensors, eLoran, lidar, electronic compasses, cellular signal positioning, video signal positioning, odometers, wheel-speed sensors, ultra-wideband, RFID, Bluetooth and more. Coverage not only includes the U.S. Global Positioning System, but it also chronicles the development of GLONASS, BeiDou and Galileo, as well as regional sysems, including QZSS and NavIC.

    In this current era of heightened GNSS interference, we are also staying on top of the numerous groundbreaking projects to complement GNSS or provide alternative PNT methodologies. From new ways to process signals to additional constellations in low-Earth orbit, we are your companion to sharing this critical information (see Converging on the Jammer).

    Uses of GPS have spread across the landscape, the seas, into air space, into outer space, driven by designers and engineers crafting new solutions for challenging problems. Wherever the industry is heading, GPS World will be there to cover it.

  • First Fix: Reliable resources at the ready

    First Fix: Reliable resources at the ready

    The GPS World Buyers Guide is the only comprehensive and continuously updated directory of leading providers of GNSS and other positioning, navigation and timing (PNT) solutions and services. 

    If you’re seeking products and services, you have two resources available at your fingertips: the print Buyers Guide that appears in our May/June issue, and the online version that’s accessible 24/7 at gpsworldbuyersguide.com.

    We’re proud GPS World’s Buyers Guide was the industry’s first online buyers guide to feature hundreds of manufacturers, products and services. The print version of our Buyers Guide has been available for more than 25 years.

    We make it easy to find what you’re looking for. You can search for manufacturers by name, or location. You can search for products and services by name, or product categories and subcategories.

    We make it easy for manufacturers and suppliers to list their products and services. It’s free because we want to ensure our Buyers Guide is all-inclusive and offers accurate and reliable information. We encourage manufacturers and suppliers not listed in our Buyers Guide to create a new listing, which can be continuously updated and seen year-round.

    The GPS World Buyers Guide is the industry’s most trusted resource of GNSS and PNT solutions and service providers. Watch for the latest version in the May/June issue and online at gpsworldbuyersguide.com.

    In the meantime, check out our Simulator Buyers Guide on page 35 of this issue. It features simulator tools, devices and software from prominent companies that aid GNSS receiver manufacturers in product design. 

    You can rely on GPS World to deliver trusted, reliable resources when you need them most. 

  • First Fix: Taking a deeper dive in 2026

    First Fix: Taking a deeper dive in 2026

    Rapid innovation is reshaping GNSS/PNT and positioning, navigation and timing (PNT) landscapes. The same can be said for the channels through which we provide this content to you. 

    GPS World is making strategic refinements to its magazine publishing schedule and digital solutions portfolio to better serve our subscribers. Our transition from a monthly print and digital edition cadence to a six-times-per-year magazine frequency will better align with buying cycles and industry events.

    That’s why the issue you are reading now will be the last of 2025. We will have plenty of new content online daily at GPSWorld.com to keep you informed on trends and new developments in the GPS, GNSS and PNT sectors.

    Going forward, GPS World will publish our print issue six times. In 2026, look for issues in February, March, May, June, September and October. We will continue to bring you the same exclusive content, including our Simulator Buyers Guide and our GNSS/PNT Buyers Guide. We’ll have our guest columns, such as Inside the Box. Plus, our popular departments PNT Corner, Evolution, Mapping Marvel, LaunchPad, MarketWatch, System of Systems and Seen & Heard will round out our print editions.

    In 2026, our cover stories will tackle transportation, defense, simulators, autonomous systems, precision agriculture and complementary PNT, as well as surveying and mapping. Every GPS World issue will continue to deliver exclusive technical content and market insights — only now, each edition will delve deeper into today’s hottest trends in GNSS/PNT.

    In tandem with our magazine content and publishing evolution, GPS World is significantly expanding its digital offerings. New and enhanced digital platforms include:

    GPSWorld.com. Watch for more exclusive content focused on the market segments that matter most.

    Weekly e-newsletters. Navigate! Weekly, Survey Scene, Defense PNT and Autonomous Arena deliver insightful columns and the latest news straight to your inbox each month.

    Custom, sole-sponsored e-newsletters, webinars and digital events. Keep an eye out for turnkey opportunities to showcase thought leadership and new technologies.

    These changes reaffirm GPS World’s commitment to being the most authoritative and effective media brand for reaching professionals in the GNSS, PNT and GPS markets. For the past 35 years, GPS World has served readers in print and online, and we have no intention of changing that now. Technology may have evolved over that time, but our dedication to providing you with the latest news and in-depth coverage will continue. 

    —GPS World Staff

  • GPS World launches new digital opportunities and printing schedule

    GPS World launches new digital opportunities and printing schedule

    As GPS World marks its 35th anniversary, we continue to evolve to meet the needs of our valued subscribers and marketing partners. This month, we unveil strategic refinements to our magazine publishing schedule and our expanding digital content and solutions portfolio plans. 

    Tod McCloskey
    Tod McCloskey

    To better align with buying cycles and industry events, GPS World is transitioning from a monthly print and digital edition cadence to a six-times-per-year magazine frequency. Remaining 2025 issues are set for September and October. Beginning in 2026, GPS World issues will publish in February, March, May, June, September and October.

    Each GPS World issue will continue to deliver exclusive technical content and market insights. 

    In tandem with our magazine’s evolution, GPS World is significantly expanding its digital content and media solutions offerings, including:

    • Expanding GPSWorld.com: We will feature more exclusive content, delving deeper into today’s hottest trends in GNSS’ and complementary PNT’s top segments: autonomous solutions, defense, mobile, machine control/precision ag, simulators, surveying, mapping and transportation
    • New Custom Media Solutions: Leading technology suppliers now have an arsenal of platforms and offerings to educate our audiences on trends and advancements
    • Expanding Enews: Navigate Weekly!, Survey Scene, Autonomous Arena and Defense PNT e-newsletters: We will deliver even beefier segment news to your inbox each week 

    GPS World’s audiences are highly engaged confirmed buyers/specifiers. We promise to continue to evolve our integrated media offerings to meet readers’ and marketers’ changing preferences — because you are, and always have been, at the center of our information constellation.

  • First fix: Our varied routes to GNSS/PNT

    First fix: Our varied routes to GNSS/PNT

    We each arrived at our current involvement with the GNSS/PNT industry by a different path. For many, it was through engineering, perhaps initially thinking of focusing on completely different challenges than those posed by extremely weak RF satellite signals, intentional interference, or ionospheric scintillation. For others, it was through surveying, which they might have entered to make a living traipsing through open fields — well, traversing them — while working independently and in nature.

    For others still, it was through one of the myriad applications of GNSS — from mapping the geographic distribution of the few remaining Amur leopards to guiding a tractor in the field, from commercial fishing in Alaska to conducting search and rescue missions, to training for military raids. Yet for others, it was through business, perhaps because they were tasked to route delivery trucks more efficiently or to track each vehicle in a rental fleet. Professor Richard Langley started out as an applied physicist and a radio tinkerer, building his first radio at the age of 14. My colleagues at North Coast Media got here via a career in journalism, with the steep subject-matter learning curve following their training in writing and editing.

    I got here mostly through my passion for maps, charts and navigation. I first became interested in maps as a child — after twice getting lost. The first time, I was 5 years old and lost track of my mother as she entered a store in Berkeley, California, and I kept walking down the street. The next time, I was 7 and had insisted on walking home alone from school in Milan, Italy. I was determined not to let it happen again. So, when I was 11, I was the only kid I knew who walked around Pisa studying a map and a compass.

    Next came the topographic maps I used for hiking. In my 20s, sailing around the Boston Harbor islands and off the coast of Maine, I learned to use nautical charts, sextants, radio direction-finders, sonar, radar, Loran C, and, finally, hand-held GPS receivers. I read my first technical article on GPS in 1985, when I was a graduate student in international security at MIT and Harvard, and the U.S. military was building the system. I studied its technical specifications and dreamt about its many possible future applications.

    In 2000, when looking for a career change and a job in journalism, I saw a posting for the position of managing editor of this magazine. I applied and 25 years later I am still in the business.

    Throughout, I always have been impressed by the deep expertise of the scientists and engineers who created this fantastic GNSS that billions of people use multiple times a day yet take for granted. Those who discount, belittle or even mock the expertise of people who have spent decades studying complex subjects — from climate change to economics, from foreign policy to epidemiology, from education to urban planning — are profoundly unaware and misguided, when not hypocritical. We need experts.

  • First Fix: War, collaboration and elections

    First Fix: War, collaboration and elections

    (Photo: Jirapong Manustrong/iStock / Getty Images Plus/Getty Images)
    (Photo: Jirapong Manustrong/iStock / Getty Images Plus/Getty Images)

    In February 1991, two Russians joined this magazine’s Editorial Advisory Board: Nocolay Ivanov, Ph.D., research and development director of the USSR’s Institute for Space Device Engineering, and Gennady Gromov, Ph.D., chief designer general for the Leningrad-based All-Union Scientific Research Institute for Radio Equipment. Both were leading experts in GLONASS.

    In October 1982, 4 1/2 years after the launch of the first GPS satellite, the Soviet Union had launched the first test satellite for its new constellation. It peaked in 1996, with more than two dozen operating satellites in orbit, then declined, hitting a nadir of just seven operational satellites in 2001.

    Additionally, early GLONASS satellites were plagued by orbital failures and short lifetimes. Many observers wrote the system off as another victim of the economic and political disarray following the collapse of the Soviet Union. Then, the new Russian government reversed the trend by substantially increasing its funding for the program. By October 2011, the full orbital constellation of 24 satellites was restored. Next year, Russia plans to launch Glonass K-2, the latest generation of GLONASS satellites.

    Following Russia’s invasion of Ukraine, however, much international scientific and technical cooperation with the country has been on hold. On April 8, 2022, the European Commission declared: “Following the Russian invasion against Ukraine and in solidarity with the people of Ukraine, the Commission has decided to suspend the cooperation with Russian entities in research, science and innovation.” Two months later, on June 11, 2022, the White House followed suit: “Consistent with U.S. domestic and international law, we will wind down institutional, administrative, funding, and personnel relationships and research collaborations in the fields of science and technology with Russian government-affiliated research institutions.”

    By contrast, cooperation between the U.S. and European space agencies continues apace, as evidenced by a recent successful test of the interoperability of GPS and Galileo receivers.

    Meanwhile, in 2024, China reached a total of 45 operational BeiDou satellites in orbit. It is also conducting research on BDS technology upgrades and technological trials for integration with low-Earth orbit PNT systems. It touts this, together with its active participation in the work of relevant United Nations bodies, as enhancing international collaboration.

    At the latest two-day meeting of the National Space-Based Positioning, Navigation and Timing Advisory Board, in early December, much of the agenda was devoted to updates on international GNSS capabilities — including Japan’s QZSS and Korea’s KPS — and discussion of how GPS compares with the other global and regional navigation satellite system constellations.

    Future GPS policies and budgets will depend largely on the choices made by the next U.S. administration.

    War, international collaboration and the periodic changes in national perspectives and priorities brought about by elections contribute as much as scientific and technical research to the prospects of GNSS — this fantastic global utility that enables us, among other things, to track the movement of containers from Shanghai to Los Angeles, fly safely from New York to Paris and coordinate universal time across our planet.

  • First Fix: Continuity and renewal on the 2025 agenda

    First Fix: Continuity and renewal on the 2025 agenda

    Photo: fatido / istock / getty images / getty images plus
    Photo: fatido / istock / getty images / getty images plus

    As we approach the holidays and if I get tired of writing about weighty scientific, technical and policy issues, I might apply for a copywriting position at Hallmark Cards. But for now we begin to think concretely about the coming year. In fact, due to our production timelines, as you are reading this issue we are busy completing the January one. So, what can you expect to see in these pages in 2025?

    First, more of the same… excellent content. Our cover stories will continue to bring you case studies from key GNSS application areas based on interviews with equipment manufacturers and end users. Our secondary features will cover bathymetric surveying; GNSS/PNT applications for consumers, science and business; autonomous vehicles; and indoor mapping. Our System of Systems section will continue to keep you informed about developments in GNSS, other PNT, and space exploration around the world. Our guest columnists — including Lisa Dyer of the GPS Innovation Alliance and Dana Goward of the Resilient Navigation and Timing Foundation — will continue to bring you their valuable perspectives. Our annual Directions section will continue to provide updates on all four GNSS and the regional constellations.

    Launchpad will continue to showcase the latest product releases and Market Watch will continue to bring you a roundup of timely industry news. Our buyers guides will continue to provide a handy reference to who makes what. Our Mapping Marvel, Research Roundup and Seen & Heard sections will continue to bring you beautiful and interesting maps, summaries of scholarly articles, and glimpses of interesting and amusing GNSS/PNT applications around the world, respectively.

    Our Authoritative Reference section will feature an article on the GPS budget, an update to “Who Runs GPS?” (see the February 2023 issue), an almanac of GNSS satellites and signals, and a survey of augmentation and corrections services. Our Inside the Box occasional section will explain the workings of different aspects of GNSS/PNT technology.

    Following Richard Langley’s fantastic 35-year run with his great Innovation column — if you missed it, see his last one, and a celebration of his work, in the November issue — the February issue will launch a new quarterly technical column and its editor (and, sometimes, author). Many of you will start guessing who this person is and the new column’s name… but my lips are sealed until then.

    I will engage our Editorial Advisory Board in more in-depth discussions of technical and policy issues and ask some of its members to write full articles. I will expand our coverage of low-Earth orbit (LEO) PNT and corrections services and introduce new content categories — such as legal issues, the consumer market and book reviews.

    I am looking for new authors, including a Washington correspondent, to report on relevant budget negotiations, legislation and policy discussions; a surveyor to report from the field about new equipment, techniques and challenges; a technology writer to cover the growth in LEO PNT constellations and other types of complementary PNT and one to cover developments in the consumer market.

    Talk to you again next year!

  • First Fix: It’s time to give time its due

    First Fix: It’s time to give time its due

    Image: agsandrew/iStock/Getty Images Plus/Getty Images
    Image: agsandrew/iStock/Getty Images Plus/Getty Images

    Timing — the unglamorous yet essential T in PNT (positioning, navigation and timing) — has been called “the invisible utility.” In fact, it’s been a long time since we last put a GNSS-timing receiver on the cover. (Partly that’s because, like with simulators, it’s hard to come up with a visually compelling image that conveys the role of such a device.)

    From St. Augustine (“What, then, is time? If no one asks me, I know what it is. If I wish to explain it to him who asks, I do not know.”) to theoretical physicist Carlo Rovelli (who argues that time is “part of a complicated geometry woven together with the geometry of space”), time is both one of the greatest mysteries of nature and one of our most practical concerns. For satellite navigation, time is both essential to its functioning and a fabulous by-product. As David Wells and Alfred Kleusberg wrote in the first “Innovation” column, in the first issue of this magazine, “One of the by-products of getting an SPS [Standard Positioning Service] position fix is that a clock in the user’s receiver is automatically synchronized to clocks in the GPS satellites to an accuracy of one ten-millionth of a second. Therefore, any GPS receiver is a very accurate time distribution device.” (“GPS: A Multipurpose System,” January-February 1990.)

    As Richard Langley wrote in another early “Innovation” column, “Thanks to minute energy changes in individual atoms of cesium and rubidium, humankind possesses the ability to synchronize clocks anywhere in the world to better than 10 nanoseconds. But given this amazing ability to measure time, we still don’t know what time actually is.” (“Time, Clocks, and GPS,” November-December 1991.)

    I procrastinated the task of writing this editorial and now another aspect of time is here to impose its claim: our production deadline. So, just one anecdote and a final quote, and I will be done, just in time.
    The anecdote. A quarter century ago, during my first time around on this magazine’s staff, when Glen Gibbons was the group editorial director, Alan Cameron the senior editor, and I the managing editor, we had just one meeting a month, called “edit check,” a couple of days before the deadline to send each issue to the printer. We printed out all the pages, laid them down in order around a large conference room table, and walked around the table examining each one and making notes about small final corrections and revisions.

    Only one page routinely had a large empty area: It was the one for Glen’s monthly editorial, which he always finalized (wrote?) at the last possible moment. I once joked that it would be blown in at the printing plant like the magazine’s subscription cards. Well, as I finish this editorial, we are at T minus two days for the November issue. Enjoy it!

    Oh, and the final quote, again from Rovelli: “The events of the world do not form an orderly queue like the English. They crowd around chaotically like the Italians.”

  • First Fix: Spoofing’s insidious threat to airliners

    First Fix: Spoofing’s insidious threat to airliners

    On Sept. 1, 1983, Korean Air Lines flight KAL007, with 269 people on board, went 360 miles off course and strayed into prohibited airspace over one of the Soviet Union’s most sensitive military installations. The pilots, who had missed some radio calls and warning shots, were unaware. Then an air-to-air missile hit the plane.

    This tragic Cold War episode helped GPS technology spread from military to civilian use because President Ronald Reagan’s deputy press secretary, Larry Speakes, said that to help prevent a repeat of the tragedy, “the President has determined that the United States is prepared to make available to civilian aircraft the facilities of its Global Positioning System when it becomes operational in 1988.” Civilian use of GPS had been envisioned from the program’s beginning, but Reagan’s announcement now guaranteed the future availability of GPS to civilians. That, and later smartphones, spawned the development of the commercial and consumer GPS industry.

    More than 40 years later, however, civilian airliners are increasingly at risk of being shot down, as well as many other equally disastrous outcomes, due to spoofing and its percolating effects on many aircraft systems. GPS Spoofing: Final Report of the GPS Spoofing Workgroup, released on Sept. 6, reports a 500% increase in spoofing this year compared to last year, with an average now of 1,500 flights spoofed per day. Among the many dangers this poses, the report states that it has led to “aircraft entering other Flight Information Regions without clearance or authorization, which creates risk of misidentification and, in the extreme case, interception or shootdown.”

    The report, based in part on a questionnaire returned by nearly 2,000 pilots — 56% of them working for airlines and 72% captains — found that more than 90% of all crew members rated their concern as moderate or higher. The three most insidious aspects of spoofing for aircraft are that pilots may not be aware of it; that GNSS receivers may continue to yield incorrect positions long after the aircraft leaves the spoofing area; and that bad data from the GNSS receiver has “severe and cascading effects” on many other systems, including the flight management system, the Ground Proximity Warning System, Hybrid IRS, the aircraft clock, weather radar, CPDLC, ADS-B and ADS-C. Spoofing also affects air traffic control, which is inundated with requests for radar vectoring during and after spoofing.

    The report finds “an overall sense of complacency and muted interest across a broad section of the aviation industry.” Two of its many recommendations to mitigate the problem jumped out at me: synching a mechanical watch to a known source at dispatch “in preparation for aircraft clock failure” and positioning a handheld GPS receiver “low down in the cockpit such that it only has a direct line of sight to the highest elevation satellites,” which makes it possible “that it may not get jammed and spoofed as easily as the externally mounted antennas.”

    Why has it come to this? What will we do about it? You can read the report here.

  • First Fix: So many questions

    First Fix: So many questions

    (Photo: Adam Smigielski/iStock / Getty Images Plus/Getty Images)
    (Photo: Adam Smigielski/iStock / Getty Images Plus/Getty Images)

    One of my favorite parts of this job — and, more generally, one of my favorite things to do in life — is to ask questions.

    Matteo Luccio
    Matteo Luccio

    For this magazine and to stay on top of the latest issues and trends in our industry, I ask questions to the members of our Editorial Advisory Board (EAB) for our EAB Q&A section, to representatives of GNSS/PNT companies for our cover stories, and to participants at conferences and trade shows.

    In my personal life, I ask questions to people I invite on sailing trips, to dinner parties and on hikes. When I am traveling or just about town, if I overhear somebody knowledgeable speak about an interesting topic — from quantum mechanics to French politics to Baroque music — chances are that I will say, “Excuse me. May I ask you a question?”

    So, here are a few of my current questions about GPS/GNSS/PNT. To make it clear that they are not in order of importance, I put them in alphabetical order.

    • How do the other three GNSS constellations benefit GPS users?
    • How is GPS faring in Congress? (On June 17, Dana Goward reported that Congress had refused the U.S. Space Force’s request to fund a program to make GPS more resilient by building and deploying small GPS satellites. Please note: I am looking for a knowledgeable “Washington correspondent” for GPS World, who could keep our readers updated on relevant developments in Congress and the executive branch.)
    • If the QZSS or NavIC regional systems became global, would that significantly improve GNSS? If so, how?
    • What are currently the most promising approaches to non-GNSS PNT for applications that do not require high accuracy?
    • What are the benefits of adding signals from even a few low-Earth orbit (LEO) satellites to a PNT solution?
    • What are the latest advancements in the scientific uses of GNSS signals, such as to develop models of the ionosphere or to test theories in fundamental physics, such as relativistic positioning?
    • What are the most promising approaches to pinpointing GNSS interference from LEO satellites?
    • What is the most promising approach to high-precision positioning with smartphones?
    • What is the status of the Chimera enhancement to the L1C signal? What benefits will it deliver?
    • What reforms in GPS governance would help accelerate modernization of the system?
    • When will M-code GPS user equipment be widely deployed to U.S. armed forces?
    • When will the Next Generation Operational Control System (OCX — the future version of the GPS control segment) become operational? What’s missing? What’s the holdup? (According to GPS.gov, the U.S. Space Force completed all 17 planned monitor station installations in July 2021.)
    • Which GNSS signals are cellphones in the U.S. legally allowed to use?

    I will pose some of these questions to our EAB over the next few months. If anybody else out there would like to chime in, please let me know.

  • First Fix: Global Glitch

    First Fix: Global Glitch

    From Hong Kong to Berlin, from Sydney to New York, the operations of hospitals, airlines, banks, and scores of other businesses and services were disrupted on July 19 due to a glitch in a software update issued by the cybersecurity firm CrowdStrike that affected computers using the Microsoft Windows operating system.

    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.

  • First Fix: By all available means

    First Fix: By all available means

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