GPS World

Category: Opinions

  • Plate tectonics and NGS’s new NSRS terrestrial reference frames

    Plate tectonics and NGS’s new NSRS terrestrial reference frames

    The adoption of the new, modernized National Spatial Reference System (NSRS) is rapidly approaching, with official implementation now expected in the first quarter of 2027.

    One of the most common questions I receive during presentations is: How will the National Geodetic Survey (NGS) account for plate tectonics in the modernized NSRS, and what does that mean for my geospatial products and services?

    First, I have some very sad news to share.

    Dr. Chris Pearson
    Dr. Chris Pearson

    Our friend and colleague, Dr. Chris Pearson, unexpectedly passed away while in Cape Town attending the May 2026 International Federation of Surveyors (FIG) conference. At the time, he was serving as a Geodetic Advisor for Trimble and as co-chair of FIG Commission 5.2.

    Chris previously worked for the National Geodetic Survey (NGS) as a Geodetic Advisor, where he played a key role in developing the comprehensive block model of crustal deformation — widely known as HTDP — across the western United States, including Alaska.

    He was an active and respected member of several professional organizations and will be greatly missed by the entire geodetic and surveying community.

    Now, let’s discuss how the National Geodetic Survey (NGS) will handle plate tectonics in the modernized National Spatial Reference System (NSRS) and what this will mean for users’ geospatial products and services.

    Map of tectonic plates (Image: Dave Zilkoski)

    Plate tectonics is the scientific theory that describes how Earth’s outer shell, known as the lithosphere, is divided into large, rigid pieces called tectonic plates. These plates float atop the hotter, more ductile rock in the mantle below and move very slowly — roughly at the same rate as your fingernails grow, about 1 to 10 centimeters per year.

    So why does plate tectonics matter for geodetic coordinates? Because the most significant geological activity — including earthquakes, volcanic eruptions, and crustal deformation — occurs primarily at the boundaries where these plates interact.

    My last newsletter highlighted several activities by the North Carolina 2022 Reference Frame Working Group (NC RFWG) that are addressing this issue and other challenges related to the implementation of the new NSRS.

    During my presentations on the modernized NSRS, I always show the National Geodetic Survey (NGS) maps that illustrate the approximate horizontal and vertical changes expected when the new Terrestrial Reference Frames (TRFs) are adopted, with coordinates referenced to epoch 2020.00. These maps provide a high-level (“30,000-foot”) overview of the anticipated changes. However, they do not include the level of detail that many users are looking for.

    Participants at these seminars and meetings consistently want to know the expected coordinate differences for their specific state or local region, and how the time-dependent components will impact their work.

    Most geospatial users now understand that International Terrestrial Reference Frame (ITRF) coordinates include a velocity component caused by tectonic plate movement. To manage these changing coordinates, the National Geodetic Survey (NGS) plans to incorporate time-dependent modeling. NGS has developed two key models — EPP2022 and IFDM2022 — to make time-dependent geodetic control practical and usable.

    • EPP2022 (Euler Pole Parameters) describes the rigid rotation of tectonic plates.
    • IFDM2022 (Intra-Frame Deformation Model) computes the internal deformation and drift within a tectonic plate.

    As shown in the figure below, the NOAA CORS Network station COLA in Columbia, South Carolina — located on the North American Plate — is moving at approximately 0.05 feet (14 mm) per year.

    This velocity is provided on the published ITRF2020 position and velocity data for the station  (NGS CORS Position and Velocity Sheet for COLA).  As a result, a surveyor working in June 2026 would observe a shift of about 0.3 feet in the ITRF2020 horizontal coordinates compared to the 2020.00 reference epoch, solely due to tectonic plate motion.

    Motion due to plate movement (rates per year) – based on ITRF2020 velocity rates

    Image: Dave Zilkoski
    (Image: Dave Zilkoski)

    The National Geodetic Survey (NGS) provides detailed information for all NOAA CORS Network (NCN) stations on the NGS NCN Station Pages. 

    In the section titled “Coordinates and Velocities”, simply click the Position and Velocity button to view the station’s ITRF2020 coordinates and velocities (referenced to epoch 2020.00), as well as the NAD 83 (2011) coordinates and velocities (referenced to epoch 2010.00).

    NGS CORS position and velocity sheet for COLA

    NGS CORS position and velocity sheet for COLA

    So, what does this mean for users?

    As previously mentioned, the National Geodetic Survey (NGS) is expected to adopt the new modernized NSRS in the first quarter of 2027. The figure below shows the change in ITRF2020 coordinate values between epoch 2020.00 and 2027.00 for NOAA CORS Network (NCN) stations in South Carolina. This shift of approximately 0.33 feet (10 cm) is the result of seven years of tectonic plate motion.

    ITRF2020, Epoch 2020 to ITRF2020, Epoch 2027 (units ift)

    ITRF2020, Epoch 2020 to ITRF2020, Epoch 2027 (units ift) Image: Dave Zilkoski
    Image: Dave Zilkoski

    That said, what will the change in NATRF2022 coordinate values be between epoch 2020.00 and 2027.00?

    This is where NGS’s EPP2022 and IFDM2022 models become essential. My February 2022 and July 2024 GPS World newsletters discussed the Euler Pole Parameters (EPP) process in detail.

    The Beta NATRF2022 website provides the Euler Pole Parameters (EPP) needed to define the relationship between ITRF2020 and the new NATRF2022 frames for the North American, Caribbean, Pacific, and Mariana plates, as outlined in NGS’s Blueprint Part 1 document. The values in the table have proven especially useful to programmers developing and testing their software.

    Beta Values for EPP

    Beta Values for EPP (Image: NGS)
    (Image: NGS)

    As stated in Blueprint Part 1, the National Geodetic Survey (NGS) will define the official relationship between ITRF2020 and the four NSRS Terrestrial Reference Frames (TRFs) through Equation 59. This equation uses the rotation matrix provided in Equation 58, which results in Equation 60.

    See the box titled “Official Relationship Between ITRF2020 and the Four NSRS TRFs” for the equations.

    Official relationship between ITRF2020 and the four NSRS TRFs

    Official relationship between ITRF2020 and the four NSRS TRFs (Image: NGS Blueprint pt. 1)
    (Image: NGS Blueprint pt. 1)

    So, what does this mean for surveyors?

    The primary purpose of the EPP2022 model is to remove the rigid tectonic plate motion from the coordinates. After applying the EPP2022 model to the ITRF2020 coordinates at epoch 2027.00, the resulting NATRF2022 horizontal coordinates for station COLA (epoch 2027.00) will change by only 0.04 feet (12 mm).

    EPP applied

    NATRF2022, Epoch 2020 to NATRF2022, Epoch 2027 in SC (units ift)

    Image: Dave Zilkoski
    Image: Dave Zilkoski

    As shown in the figure, the EPP2022 model removes most of the horizontal movement caused by seven years of tectonic plate motion — reducing it to just 0.04 feet (1.2 cm) at station COLA. In other words, the EPP model effectively removes the vast majority of plate tectonic effects.

    Additionally, the plot shows that the relative horizontal differences between nearby marks are very small — typically less than 0.01 feet (0.3 cm).

    As previously mentioned, the NGS maps provide a high-level (“30,000-foot”) view of the expected changes between the current NSRS and the new modernized NSRS. So, what are the anticipated differences between NAD 83 (2011) and NATRF2022 specifically in South Carolina?

    The figures below illustrate the differences in both horizontal position and ellipsoid heights between NAD 83 (2011) and NATRF2022 coordinates across South Carolina.

    NAD83 (2011), Epoch 2010 to NATRF2022, Epoch 2020 Horizontal Changes in SC (Units ift)

    NAD83 (2011), Epoch 2010 to NATRF2022, Epoch 2020 Ellipsoid Height Changes in SC (Units ift)

    The magnitude of these changes varies depending on your location. To illustrate this, I’ve provided two additional examples: one for Iowa and one for Washington State. As the plots clearly show, the differences in these states are noticeably different from those depicted for South Carolina.

    NAD83 (2011), Epoch 2010 to NATRF2022, Epoch 2020 Horizontal Changes (Units ift)

    That said, the differences between NATRF2022 at epoch 2020.00 and epoch 2027.00 in Iowa and Washington State — after applying the EPP2022 model — are very similar to the values shown for South Carolina.

    However, readers should note that the differences in Washington State increase as you move toward the coast. This is because the area lies near the boundary between the North American Plate and the Pacific Plate. The Juan de Fuca Plate, a small microplate in the eastern North Pacific, is also actively involved in this region.

    (See the box titled “Juan de Fuca Plate.”)

    NATRF2022, Epoch 2020 to NATRF2022, Epoch 2027 (units ift)EPP Applied

    Juan de Fuca Plate

    The Juan de Fuca plate or Juan de Fuca microplate is a small oceanic tectonic plate (microplate) generated from the Juan de Fuca Ridge that is subducting beneath the northerly portion of the western side of the North American plate at the Cascadia subduction zone.

    Image: Dave Zilkoski
    Image: Dave Zilkoski

    What about orthometric height changes in the new NSRS?

    As an example, the orthometric height differences between NAPGD 2022 and NAVD 88 in South Carolina are expected to range from approximately -0.8 feet to -1.3 feet.

    Difference between NAPGD2022 and NAVD 88 (Units ift) in S.C.

    Image: Dave Zilkoski
    Image: Dave Zilkoski

    The differences between NAPGD 2022 and NAVD 88 vary significantly depending on your location. The figures below illustrate these orthometric height differences for Iowa and Washington State as examples.

    Difference between NAPGD2022 and NAVD 88 (Units ift)

    The new NSRS will use a gravimetric geoid (GEOID2022) rather than a hybrid geoid (GEOID18) to compute GNSS-derived orthometric heights.

    During my presentations, I always remind participants that a hybrid geoid is not a “true” geoid. It is simply a transformation model that converts ellipsoid heights in one reference frame to orthometric heights in a specific vertical datum. Specifically, GEOID18 is a transformation tool that allows users to derive NAVD 88 orthometric heights from NAD 83 (2011), epoch 2010 ellipsoid heights.

    The figure below shows the differences between the gravimetric geoid model GEOID2022 and the hybrid geoid model GEOID18.

    Important note: Users cannot use GEOID18 with NATRF2022 ellipsoid heights to obtain NAVD 88 orthometric heights. Instead, GEOID2022 must be used with NATRF2022 ellipsoid heights to compute orthometric heights in the new vertical datum, NAPGD 2022.

    Differences between GEOID2022 and GEOID18 in SC (Units ift)

    As noted at the outset of this newsletter, the transition to the modernized National Spatial Reference System (NSRS) is rapidly approaching, with official implementation scheduled for the first quarter of 2027.

    The National Geodetic Survey (NGS) released the following announcement on May 28, 2026:

    Public Testing Period Ends for Key NSRS Modernization Products

    NGS has declared the following products stable and ready for implementation planning and integration activities ahead of the official release:

    • North American-Pacific Geopotential Datum of 2022 (NAPGD2022)
    • New Terrestrial Reference Frames of 2022:
      • North America (NATRF2022)
      • Pacific (PATRF2022)
      • Caribbean (CATRF2022)
      • Mariana (MATRF2022)
    • State Plane Coordinate System of 2022 (SPCS2022)

    Additional modernization products, including NCAT, OPUS, and the Data Delivery System, are scheduled for release later in 2026.

    NGS news

    Public testing period ends on specific NSRS modernization products

    Image: NOAA

    Image: NOAA

    This newsletter highlighted the role of the EPP2022 model in accounting for plate tectonics and illustrated the anticipated local differences between the current National Spatial Reference System (NSRS) and the upcoming modernized version.

    Future editions will continue to explore additional NGS Beta products as they are released later in 2026.

  • Update on NC 2022 reference frame working group: Preparing information for NC geospatial providers and users

    Update on NC 2022 reference frame working group: Preparing information for NC geospatial providers and users

    In my October 2025 GPS World Newsletter, I highlighted professional societies forming working groups for the new NSRS — the National Society of Surveyors (NSPS), the American Society of Photogrammetry and Remote Sensing (ASPRS), and the American Association for Geodetic Surveyor (AAGS). Under Gary Thompson’s leadership, the North Carolina Geodetic Survey also established the North Carolina 2022 Reference Frame Working Group (NC RFWG), which includes representatives from NC agencies that produce or use geospatial products and services. This newsletter spotlights several NC RFWG activities to inform and assist other agencies and working groups.

    As noted in my previous newsletter, NC RFWG agencies are proactively conducting self-assessments of their needs and processes to identify challenges and opportunities early, enabling a smooth transition and sustained operational efficiency. The working group meets monthly to review progress on activities.

    One key task of the working group was to develop a short online questionnaire. The goal was to open a dialogue with geospatial professionals and better understand their readiness for the upcoming modernization of the National Spatial Reference System (NSRS).

    The questionnaire was designed to address the following key questions:

    • Are you prepared to implement the new NSRS once the National Geodetic Survey (NGS) officially adopts it?
    • Do you have the necessary tools and resources in place to ensure a smooth transition?
    • Has your organization established a timeline for transitioning to the modernized NSRS?
    • What concerns do you have regarding the transition to the new NSRS?

    The section titled “Introduction of North Carolina Questionnaire” explains the purpose and background of the survey, while the section titled “North Carolina Online Questions” presents the list of questions included in the questionnaire.

    Introduction of the North Carolina Questionnaire

    This questionnaire seeks stakeholder input on the upcoming modernization of the National Spatial Reference System (NSRS). Your feedback is welcome on the proposed questions, as well as any concerns about the datum transition, tools (such as updated NCAT, OPUS, and SPCS2022), data transformation strategies, workflow impacts, and preparation needs.

    The National Geodetic Survey (NGS) is replacing the North American Datum of 1983 and the North American Vertical Datum of 1988 with new plate-fixed terrestrial reference frames (NATRF2022, PATRF2022, CATRF2022, and MATRF2022) tied to the International Terrestrial Reference Frame 2020, along with the new vertical datum, the North American-Pacific Geopotential Datum of 2022.

    In spring 2027, new horizontal and vertical datums will be implemented:

    Horizontal

    • North American Terrestrial Reference Frame (NATRF2022)
    • Replaces the North American Datum of 1983 (2011)

    Vertical

    • North American-Pacific Geopotential Datum of 2022 (NAPGD2022)
    • Replaces North American Vertical Datum of 1988

    Units

    • 14B NCAC 03 .0602 REQUIRED FOOT CONVERSION

    North Carolina Online Questions

    The section titled “Results of North Carolina Online Questionnaire” summarizes the survey responses collected as of April 27, 2026.

    [Note: NCPMA refers to the North Carolina Property Mappers Association, and LGUC refers to the North Carolina Local Government Committee.]

    Results of the North Carolina Online Questionnaire

    (April 27, 2026)

    This questionnaire solicited input from the North Carolina Property Mappers Association (NC PMA), the North Carolina Geographic Information Coordinating Council (GICC), and the North Carolina Local Government Committee (LGC). Although focused on North Carolina, the results may benefit other working groups. The NC working group is reviewing all feedback—especially regarding the Spring 2027 datum change—and will develop materials to address it.

    In addition to the questionnaire, the working group prepared a short guidance document on the new reference frames for local governments and state agencies. It outlines how to prepare for the 2027 datum change and covers:

    • Preliminary steps for transitioning when NGS and North Carolina officially adopt the new datums in 2027.
    • Actions users can take now to ready NSRS‑referenced data for the modernized NSRS and the shift from U.S. Survey Foot/International Foot.
    • Estimated coordinate changes with the 2027 adoption of:
      • North American Terrestrial Reference Frame (NATRF2022)
      • North American-Pacific Geopotential Datum of 2022 (NAPGD2022)
      • New national geoid model (Geoid2022)
      • North Carolina State Plane Coordinate System of 2022 (SPCS2022)
    • Current NC statewide digital orthoimagery acquisition cycle and statewide lidar collection schedule.
    • How the NC CORS and Real-Time Network (RTN) will support the modernized NSRS.
    • Web links to more detailed resources.


    The working group is developing a case study on preparing a FEMA Elevation Certificate using the modernized NSRS (NATRF2022 and NAPGD2022). It will be featured in upcoming newsletters. The North Carolina Geodetic Survey will host the materials on its website, and I’ll share the public link once it’s available.

  • GPS World EAB Q&A: Which emerging sectors are driving the most demand for advanced PNT?

    GPS World EAB Q&A: Which emerging sectors are driving the most demand for advanced PNT?

    We asked our Editorial Advisory Board (EAB) which emerging sectors are driving the most demand for advanced positioning and timing solutions right now?

    Find their responses below.

    Paul McBurney, oneNav
    Paul McBurney

    “The defense sector needs an off-the-shelf GNSS module that is small, light and low power, yet also highly resilient — such as a military-grade location system — to satisfy the insatiable growth in drones. While this segment is about a tenth of the total commercial vehicle market, it is significant compared to the emerging autonomous driving segment, where the need for resilience is still trying to figure out the cost-benefit of mitigating intentional interference.”

    Jules McNeff, Overlook Systems Technologies
    Photo: Jules McNeff

    “If I had to pick newly emergent sectors with the highest need for precise and continuous PNT, I would say the autonomous system operations sector and portion of the artificial intelligence (AI) sector. AI cannot provide spatially or temporally ‘intelligent’ support if it does not have access to precise positioning and timing information from outside itself. PNT sources do not depend on AI, but ‘autonomous’ AI must have reliable PNT.

    MigueL Amor, Septentrio
    Miguel Armor

    “The primary driver is the broad adoption of autonomy and automation across industries such as construction, logistics, agriculture, infrastructure, defense, or even entertainment. Amplifying this demand is the proliferation of smaller and lighter UAVs, drones and robots. Where a single manned platform once required one navigation system, a drone swarm may require hundreds or thousands of units. It is the combination of these two forces, adopting autonomy and automation and multiplying platforms, that is driving demand growth.”

    Mitch Narins, Strategic Synergies
    Mitch Narins

    For many, the meaning of advanced positioning and timing solutions equates to solutions that provide higher accuracy and precision. For me, achieving an advanced PNT solution must require equal focus on the other PNT metrics — availability, integrity, continuity and coverage. Given the tumultuous state of the world these days, there is an emerging demand for solutions that enable resilient PNT in the defense sector, the commercial aviation and maritime sectors, in telecommunications and in power

  • Peak XV: The framework that measured Mount Everest

    Peak XV: The framework that measured Mount Everest

    A ceiling fan slowly churned, stirring the hot, humid air. Outside, warm rains pelted the muddy streets as distant langurs whooped in the thick jungle mists below.

    An incessant fly caught the attention of the office’s lone occupant, hunched over a table covered with a large grid-lined sheet of paper. Pencils, erasers, French curves and straightedges lay scattered next to a stack of calculation sheets, but the man holding a pencil in one hand gripped a rolled newspaper in the other, intent on his battle with the fly.

    Suddenly, the door burst open.

    “Mr. Waugh!” the intruder exclaimed, panting as he rushed in.

    “Radhanath,” Waugh replied in surprise, looking up from his maps. “I thought you were in Calcutta, 1,600 km away.”

    “Yes, Mr. Waugh, I was, but this is too important to deliver by post.”

    “Really, Radhanath. You intrigue me,” replied Waugh. “Come out with it. Your excitement is adding to this already unbearable heat.”

    “Sir,” Radhanath tried to say calmly. “I have discovered the highest mountain in the world!”

    That conversation happened in 1852. It was the crown jewel of an effort that began 50 years earlier. Britain was on the ascent. Surveying was the mathematics of empire. India, Britain’s largest protectorate, had never been systematically mapped. The British East India Company needed to know what minerals, crops and commodities could be turned into profitable enterprises, where they were, and how to move them to ports. This depended on accurately mapping India. Infantry officer William Lambton proposed an audacious solution: measure the entire subcontinent with triangles.

    William Lambton
    William Lambton

    Lambton was granted the commission, and on April 10, 1802, the Great Trigonometrical Survey (GTS) of India began with a humble but critical baseline from St. Thomas Mount near Madras, 12 km south to Perumbauk Hill. Everything depended on the accuracy of this first baseline: even the smallest error would multiply as triangles spread across the subcontinent. Perfection was essential. The distance was measured with a 100-ft steel chain protected from the sun beneath A-frame tents to prevent thermal expansion. It moved slowly, 100 ft at a time from start to finish. Every link mattered. The baseline took 57 days.

    To guarantee perfect alignment, Lambton relied on a massive custom-built theodolite. It weighed 1,102 lbs, requiring 12 men to carry. Surveyors planted stakes, stretched strings, and used the theodolite to correct for every change in elevation, turning a simple chain measurement into the geodetic foundation of the entire survey.

    Time marched on faster than the survey. The East India Company estimated five years, but by 1818, the survey reached west to Mangalore and north to Hinganghat. It was too slow. Lambton’s vision of “an uninterrupted series of triangles…from sea to sea…to an unlimited extent in every other direction,” a complete geometric quilt covering India, proved implausible. Malaria took its toll. Lambton’s health declined and in 1823 he died at Hinganghat. George Everest inherited the survey.

    The map of triangles covered Madras to Mangalore.
    The map of triangles covered Madras to Mangalore.
    George Everest
    George Everest

    Everest recognized Lambton’s dream of total coverage would take centuries. Instead, he conceived a “gridiron” of chains running north–south and east–west, intersecting at right angles, scaffolding to which localized surveys could be tied. The shift is evident on the GTS map: dense triangulation in south-central India reflects Lambton’s ambition, while the more open, structural network elsewhere reveals Everest’s pragmatism.

    By the 1830s, Everest’s survey party had grown into slow-moving caravans, reaching as many as 1,000 people at peak times. Contemporary accounts describe columns supported by elephants, horses and camels, with hundreds of porters carrying tents, instruments and provisions. The logistics were immense: scouts rode ahead to negotiate passage with villages, reapers with scythes gathered grass for the animals, hunters supplied fresh meat and a traveling treasury paid workers and suppliers. To villagers, an approaching column appeared like a military invasion. Negotiations for assistance and safe passage could halt the survey for days.

    The survey’s path was relentless. The Great Arc bisected India along the 78th meridian, from Cape Comorin to Bangalore, across the Deccan Plateau, through Hyderabad, over the northern plains to Dehra Dun at the Himalayan foothills. They didn’t simply pass through. They stayed. Sometimes for weeks, building 50 ft masonry towers to mount the theodolites.

    When daytime heat and haze made measurements impossible, Everest shifted to night surveying using powerful lanterns visible from 30 miles away. They constantly adapted due to temperature, atmospheric refraction, verification baselines measured at the chain ends. Every measurement propagated from that first line at Madras; a minor error would compound over thousands of miles.

    The price was paid in lives. Malaria wiped out entire parties. Three officers died in the Terai, the malarial lowlands of northern India. Two more retired, health-shattered. Everest himself contracted malaria repeatedly, suffering partial paralysis. The climate, he wrote, was “very deadly.”

    Andrew Waugh
    Andrew Waugh

    The survey transformed the land. To achieve clear sight lines, villages were razed, sacred hills appropriated, and community supplies exhausted. Yet the work continued. In December 1841, almost 40 years since the GTS began, the 1,500-mile Great Arc was complete. The spine was in place. Everest retired in 1843, passing the work to Andrew Scott Waugh, who extended the gridiron eastward. Nepal and Tibet were closed to outsiders. Waugh understood the distant Himalayan peaks, more than a hundred miles away, would have to be measured from the border stations anchored to the GTS framework. Accuracy became even more critical. This shift in focus from Everest’s large sprawling triangles inching north like a spider’s web forming the Great Arc, to Waugh’s tight triangles hugging the Himalayan frontier is visible on the GTS map.

    Over the next decade, Waugh’s teams pushed eastward through the jungles of Bengal, Bihar and Orissa, verifying baselines, fixing latitudes and longitudes astronomically, establishing stations that brought the peaks within mathematical reach. Along the entire border, surveyors recorded the peaks.

    Close-up of the border survey stations used to observe Peak XV. (Credit: Royal Geographical Society)
    Close-up of the border survey stations used to observe Peak XV. (Credit: Royal Geographical Society)

    To measure Peak XV, six observation stations were selected across the Terai, the deadly malarial lowlands chosen for the clear site lines to the summit. From these stations, surveyors recorded azimuth and elevation angles across multiple seasons. They measured the summit at sunrise, when the peak was first illuminated. None of the surveyors knew the height of the mountains they were observing because distance could not be measured directly. Only when all stations were plotted on a map could the peak’s position be fixed and the elevation calculated. This high-level mathematics fell to the human computers in Calcutta, led by Radhanath Sikdar.

    Radhanath Sikdar
    Radhanath Sikdar

    By 1851, Sikdar had risen to chief computer, directing the department that transformed field observations into verified measurements. The 1851 Survey Manual acknowledged his distinction: “Babu Radhanath Sickdar, the distinguished head of the Computing Department…whose intimate acquaintance with the rigorous forms and mode of procedure…render his aid particularly valuable.” Yet, neither his education nor his geodetic calculation training prepared him for the complexities of the Himalaya problem. Nonetheless, he took the raw observations and calculated the mountains’ heights to determine which, if any, of the distant peaks was truly the highest point on Earth.

    Sikdar calculated the height of each of the peaks. There were many. It was slow, meticulous work. Peak XV required more than standard calculation. Six observation stations produced six independent height measurements, each requiring corrections for atmospheric refraction (light bending through air layers of varying density and temperature), Earth’s curvature (the summit was more than 100 miles away), and plumb-line deviation (the Himalayas’ mass pulled survey instruments slightly toward the mountains).

    Sikdar applied the Method of Least Squares, a statistical technique for extracting the most probable value from multiple observations. Each station’s measurement carried uncertainty; combining all six through rigorous mathematics yielded a more reliable result.

    The calculation took months. When Sikdar finished, he was stunned: exactly 29,000 ft recalculated and received the same result. The precision seemed too perfect. Sikdar knew the stakes. This wasn’t just another mountain. His calculations were correct. Peak XV was the highest point in the world, Chomolungma, meaning the goddess mother of the Earth. Such a discovery demanded the honor of delivering the news in person.

    In April 1852, Sikdar traveled 1,600 km from Calcutta to Dehra Dun. The journey took weeks. He carried the calculations in his satchel and the announcement in his mind.

    When Sikdar burst into Waugh’s office with the news, Waugh worried that exactly 29,000 ft (8,830 m) would make surveyors appear to have simply rounded. 2 ft were added, a small fiction to preserve credibility. The official height for Peak XV became 29,002 ft.

    Waugh spent four years verifying before the official announcement in March 1856. The mathematics were sound from the moment Sikdar burst into that office. Then, 20 years later, the 1875 Survey Manual erased Sikdar’s name entirely. The British press called it “robbery of the dead.”

    Sikdar’s calculations have stood the test of time. The 1954 Survey of India measurement, 102 years later, yielded 29,028 ft, a minimal difference. In 1999, GPS technology placed a receiver on Everest’s summit for the first time: 29,035 ft. The 2015 earthquake prompted the most comprehensive measurement yet.

    On May 22, 2019, at 3 a.m., Nepali surveyor Khimlal Gautam departed Everest’s South Col for the 10-hour climb carrying 90 lbs (41kg) of equipment. The pre-dawn timing avoided crowds: the weight included a Trimble R10 GNSS receiver and ground-penetrating radar to distinguish rock height from snow depth. Eight continuously operating reference stations (CORS) were positioned across Nepal to receive signals from GPS, GLONASS, Galileo and BeiDou. Chinese surveyors simultaneously measured from the north.

    Gautam spent hours on the summit, collecting data while his body slowly consumed itself in the death zone. He lost a toe to frostbite. A team member nearly died from oxygen depletion. Gautam understood, “Mount Everest symbolizes something in Nepal, but it’s not only a Nepal asset, it’s a world asset.”

    The map of the Great Trigonometrical Survey. (Credit: Survey of India, via David Rumsey Collection)
    The map of the Great Trigonometrical Survey. (Credit: Survey of India, via David Rumsey Collection)

    On Dec. 8, 2020, Nepal and China jointly announced their result, agreeing for the first time the height was 29,031.69 ft. Sikdar’s error across 168 years was 31.69 ft, an accuracy of 0.11%.

    From that moment in Dehra Dun, Sikdar, dusty from the road, calculations in hand, certainty in his voice, we trace backward through 50 years of framework building to understand what made that measurement possible. Peak XV, hidden in plain view, seen for hundreds of miles, refusing to be known, was finally measured.

    Once we have measured it, we want to believe we know it, but the Indian and Eurasian tectonic plates continue to collide, pushing the mountain up four millimeters per year. Earthquakes in the region change the topography. The geoid problem persists: What does “sea level” mean 440 miles from the coast in a gravitationally dense region? Modern surveyors still grapple with the fundamental question: What does “height” mean when measured against a theoretical reference surface?

    The Great Trigonometric Survey proved that surveyors could measure what they couldn’t touch, calculate what they couldn’t reach, and verify what they couldn’t see. It required building the geodetic infrastructure across a subcontinent, maintaining mathematical precision across decades, and accepting brutal human costs.

    Then, the computer was a man. The information was in his satchel. The message was delivered in person. It was the first time the height of the highest known point was determined not by a physical barometer on a summit, but by mathematics alone, a man solving equations in a room 440 miles away. Sikdar proved the impossible: What couldn’t be touched could be measured, what couldn’t be reached could be calculated, and a man dusty from the road could hold the height of the world in the palm of his hand.

    Four names for one mountain. Each represents a different understanding. Its ancient name, Chomolungma, and Sagarmatha, its national identity. Peak XV, its cartographic name marking the audacious attempt to measure it, and the name Mount Everest, the crowning achievement, a proclamation honoring mathematics, from Hipparchus who is credited with developing trigonometry to the computers, like Sikdar. It stands as a monument to all the surveying and cartography, especially of the 19th century accomplishing the impossible against extraordinary odds.

    Surveying and mapping are jobs of courage and determination exploring the unknown, risking death in malaria-infested jungles, Everest working while stricken with partial paralysis, Abdul Hamid crossing a forbidden border, and Gautam’s predawn climb. They all understood what mattered was worth the risk. It is the surveyor’s call to arms: measure the Earth.

  • Society of Land Surveyors of Iowa annual meeting recap

    Society of Land Surveyors of Iowa annual meeting recap

    In my February GPS World newsletter, I highlighted that the National Geodetic Survey (NGS) staff participated in GeoWeek 2026 in Denver.  They engaged with geospatial product and service users and provided the latest updates on the status of the modernization.  On March 25, 2026, as President of American Association for Geodetic Surveying (AAGS), I participated in a GeoWeek webinar titled “NSRS Modernization is Here: What Surveyors Need to Know Now.”

    The webinar was based on presentations by NGS and others at GeoWeek 2026.  The webinar provided the status of NGS’s new modernized NSRS and the professional societies (AAGS, ASCE, ASPRS, and NSPS) addressed how they are helping others to prepare for the change. It is available to everyone under the “On-Demand Webinars” section of Geo Week News here: https://www.geoweeknews.com/webinars.

    This newsletter will highlight the 2026 Society of Land Surveyors of Iowa (SLSI) Annual Meeting, which I had the opportunity to attend at the SLSI 89th Annual Land Surveyors Conference, held on March 4-6, 2026, in Ames, IA.

    First, at the end of February’s newsletter, I shared my main thoughts and concerns that I believe NGS and the broader community should carefully consider before NGS adopts the new modernized NSRS.

    I encourage you to watch the GeoWeek Webinar mentioned above for the latest update from NGS on the modernized NSRS.

    I have already shared my concerns directly with NGS, but it’s important that they also hear from the user community. You can provide feedback via [email protected], user forums, or upcoming webinars and Q&A sessions.

    Although I covered these points in my last newsletter, I believe they remain important, so here’s a shorter version of my key thoughts and concerns:

    • Timeline uncertainty: Clearer, more frequent milestone updates (beyond the Track Our Progress page) would help manage expectations.
    • OPUS and processing continuity: NGS should commit to a longer grace period — or ideally a defined parallel support window — for legacy OPUS tools (particularly OPUS-Projects 5) after the official adoption of the modernized NSRS.
    • Data access and usability in the new DDS: The new web-based system needs to provide robust APIs or export options that are comparable to those in current datasheets/legacy tools.  
    • Transformation tools and legacy data handling: Users need confidence that transformations minimize errors, especially in deformation-prone areas.
    • Communication and outreach: Case studies, training resources, and FAQs that describe real-world practical examples, tailored to common workflows, need to be developed and documented.

    Again, I encourage anyone reading this (including NGS staff) to test the beta products actively, submit detailed feedback, and participate in forums/Q&As. The community input will make or break the success of this once-in-a-generation update

    Regarding the 2026 Society of Land Surveyors of Iowa (SLSI) Annual Meeting, I was grateful to receive the invitation and truly enjoyed attending. As always, I came away from this gathering of surveyors with valuable insights.

    The conference was exceptionally well organized, with plenty of time for meaningful interactions among attendees, exhibitors, and speakers. In total, 285 people attended.

    As expected, I presented on the new modernized NSRS. The topics I covered are listed in the box titled “Topics Addressed During my ½ Day Session on the New NSRS.”

    I was fortunate to have Ben Sullivan, Seiler Geospatial, set the stage for my presentation by providing a short introduction to the new modernized NSRS.  He provided an overview that addressed: (1) what the new national datum is, (2) how it will affect the geospatial community, and (3) how users can prepare for it once officially released by the NGS.

    Topics Addressed During My Half-Day Session on the New NSRS

    1. What to expect between NAD 83 (2011) and NATRF2022 in Iowa?
      • Why is NGS modernizing the NSRS and what are the expected coordinate changes in Iowa?
      • How are reference frames and datums defined?
      • What are the differences in CORS coordinates between the Multi-year CORS Solution 2 (MYCS2) and Multi-year CORS Solution 3 (MYCS 3) in Iowa?
      • What does NGS mean by time-dependent coordinates and why is it necessary for the new, modernized NSRS?
      • How will plate tectonics be handled in the new, modernized NSRS?
      • What’s the difference between NAD 83 (2011) epoch 2010.0 and NATRF2022 epoch 2020.0 in Iowa?
      • What are the differences between Reference Epoch Coordinates (REC) and Survey Epoch Coordinates (SEC)?
      • What’s the difference between ITRF2020 and NATRF2022 in Iowa?
      • How do you use NCAT to convert between reference frames and compute State Plane Coordinates?
      • Why is it important to have the appropriate metadata of your old projects for the implementation of the new, modernized NSRS?
    2. What to expect between NAVD 88 and NAPGD2022 in Iowa?
      • How will orthometric heights be determined in the new, modernized NSRS; that is, how will NAPGD2022 orthometric heights be determined in the new NSRS?
      • Review of Computing GNSS-Derived Heights
      • What’s the estimated difference between NAVD 88 and NAPGD2022 epoch 2020.0 in Iowa?
      • How will NAPGD2022 Orthometric heights be determined using GEOID2022?
      • What are the differences between GEOID2022 models and Hybrid Geoid Model GEOID18 in Iowa?
      • How will NAPGD2022 affect the National Flood Insurance Program and the Elevation Certificate?
    3. Updates from the National Geodetic Survey at GeoWeek 2026

    Many of the topics covered in my session have been addressed in previous newsletters. For example:

    • My June 2020 newsletter explained how NAPGD2022 orthometric heights will be determined using GEOID2022, and why NGS will require GNSS occupations on primary marks when submitting leveling projects.
    • My October 2022 newsletter discussed NGS’s Multi-year CORS Solution 3 (MYCS 3).
    • My August 2022 newsletter covered Reference Epoch Coordinates (REC) and Survey Epoch Coordinates (SEC).
    • My March 2026 GPS World newsletter addressed the updates from NGS presented at GeoWeek 2026.

    Whenever I attend conferences, I visit exhibitors to ask about the modernized NSRS. Many had heard of it, but only a few could explain the differences or how their company will adapt products and services to the new reference frames. Several said their company is aware of the change but couldn’t specify how or when they’ll respond. I encourage all users to contact their equipment and software providers and request a detailed plan for addressing the new NSRS.

    I want to highlight two sessions I found both very interesting and important for surveyors. They were presented by Todd Horton, PE, PLS of Meridian Geospatial.

    Meridian Geospatial Consulting   Todd Horton, PE, PLS, is the owner of Meridian Geospatial Consulting, LLC.  Todd has provided technician training and continuing education seminars for the land surveying industry since 2005.   Todd served in the US Air Force and with the Illinois Department of Transportation in planning, design, construction, surveying and maintenance of civil engineering projects including commercial structures, airfields, utility systems and highways.  He joined the full-time faculty at Parkland College in Champaign, IL, where he taught land surveying and construction management courses for 25 years. Todd founded the land surveying associate degree program at Parkland College in 2001.   Having retired from full-time teaching, Todd has joined Farnsworth Group Inc. as a part-time senior project land surveyor.  You can reach him at [email protected].   (From https://www.meridiangeospatial.com/)

    One of Horton’s presentations was titled “Professional Ethics.” In it, he highlighted how new technology is reducing the size of surveying crews and improving overall efficiency. However, this comes at the cost of reduced opportunities for mentoring the next generation of survey technicians and surveyors.

    I’ve recreated his diagram below to illustrate the issue.

    Crew Size vs. Mentorship

    Crew vs Mentorship. (Recreated from Todd Horton presentation)
    Crew vs Mentorship. (Recreated from Todd Horton’s presentation)

    As shown in Horton’s diagram, while new technology increases efficiency and allows for smaller survey crews, it also reduces the time available for surveyors to mentor technicians and the next generation of professionals.

    Training and mentoring are extremely important for the continued growth and development of individuals in the surveying and mapping community.

    He explained that the world consists of two types of individuals: specialists, who have a narrow skill set and limited opportunities, and generalists, who possess broader knowledge and skills, think multi-faceted, and are forward-looking.

    He emphasized that a professional surveyor typically needs 3 to 5 surveying technicians to successfully complete a project. While professional surveyors regularly attend training sessions (as evidenced by many participants at this conference), technicians often have little or no access to formal training.

    He advocated that technicians should be trained as generalists. This means equipping them not only with better tools and equipment, but also with a strong foundational knowledge and skill set — especially understanding the “why” behind the “how.” This deeper knowledge enables them to prevent problems before they occur and effectively troubleshoot issues when they arise.

    I addressed this same concern in my November 2022 newsletter, where I warned that the industry is creating a growing number of “buttonologists” — technicians who rely heavily on pushing buttons without deeper understanding.

    This trend concerned me then, and it still does today. That’s why I was especially pleased to hear Todd directly address the issue and offer a clear path forward for improving training and development for both technicians and surveyors.

    Excerpt from November 2022 GPS World Survey Scene Newsletter

    A participant at one of my workshops stated that “GPS has made geodesists out of all of us.” In my opinion, the advancements in GNSS equipment and processing software provided some users with a “false sense of knowledge or security” that they understood what was happening within the “black box.” One of my colleagues at NGS said that the new equipment and software programs were creating a field force of “buttonologists.”

    He highlighted that the surveying community needs more technicians than licensed professionals. As a result, we should prioritize training and development for technicians. This is a constant need and would help reduce turnover rates.

    He also emphasized the importance of growing future professionals from within the technical ranks. Doing so would increase technicians’ motivation and desire for advancement, making them more eager to take on greater responsibility and pursue professional growth.

    He provided the following training approaches:

    • On-the-job training
    • Self-guided study
    • Continuing education resources
    • Online content
    • College courses
    • Live skill training

    He noted that these investments in training will yield the following advantages in professional and organizational development:

    • Enhanced employee skills
    • Opportunities for career advancement
    • Stronger organizational performance
    • Sustained competitiveness via continuous learning
    • Increased productivity
    • Higher employee retention
    • A thriving culture of innovation

    Horton also discussed a training program he’s involved in that not only trains technicians but also includes training for the trainers. This “train-the-trainer” approach helps accelerate the program’s growth and impact.

    For more information, I encourage you to reach out to Horton directly for additional details about his programs and his ideas on improving technician training.

    Horton also gave a very good session on a very difficult subject, that is ALTA/NSPS “Relative Positional Precision (RPP).”  

    As a side note: see the box titled “Top 5 Key Changes in the 2026 ALTA/NSPS Standards” for the key changes in the 2026 ALTA/NSPS standards. Detailed information on the ALTA/NSPS 2026 document can be downloaded at the following NSPS weblink: https://nsps.us.com/page/2026ALTA.

    Top 5 Key Changes in the 2026 ALTA/NSPS Standards

    1. Precision (RPP): The clarification of RPP is a core technical change. While it does not alter how surveys are performed, it improves consistency and understanding of measurement quality expectations across the profession.
    2. Shift from “on the ground” to “practices generally recognized as acceptable” (Sections 5 & 6): This is one of the most significant forward-looking changes. It explicitly accommodates modern technologies such as drones, lidar and future tools (including AI), without locking the standards to specific methods.
    3. Expanded guidance on sourcing title evidence when a recent title commitment is unavailable: This change directly affects research responsibilities and risk management, especially on projects where title information is incomplete, delayed, or unconventional.
    4. Requirement to note evidence of possession or occupation along the entire perimeter: This materially broadens what must be considered and documented in the field, regardless of how close that evidence is to the boundary line – an important title-risk issue.
    5. Clarification that verbal (“parol”) statements must be noted when made: This adds explicit documentation requirements tied to conversations with landowners or occupants, which can be critical in dispute resolution and liability defense.

    Todd started his presentation by providing RPP as defined by ALTA/NSPS (2026):

    • Relative Positional Precision (RPP) is the acceptable indicator of measurement quality on an ALTA.NSPS Land Title Survey.
    • It is defined as the length of the semi-major axis, expressed in meters or feet, of the error ellipse of the line connecting the monuments or witnesses marking adjacent boundary corners of the surveyed property at the 95 percent confidence level.

    His session was organized into nine sections labeled RPP Keys for Success:

    1. Choose one equipment and a measurement method based on the accuracy needs of the project.
    2. Use well-adjusted instruments and procedures to eliminate systematic errors in measures.
    3. Make internal checks to detect blunders in measurements.
    4. Make redundant measurements to have a large degree of freedom.
    5. Access the quality of control that will be used.
    6. Avoid weak network geometry.
    7. Organize all field measurements for software input.
    8. Establish standard errors for all observation conditions.
    9. Adjust and analyze results.

    In these sessions, he covered fundamentals including:

    • precision vs. accuracy,
    • systematic vs. random errors, and
    • absolute vs. relative accuracy.

    Horton emphasized that systematic errors follow mathematical or physical laws and can usually be modeled or reduced with proper procedures, while random errors persist after blunders and systematic errors are addressed. By using improved equipment and proper procedures to detect, reduce, or remove errors, users lower the uncertainty in their results — reducing uncertainty should be a goal for any product or service. 

    Many people are familiar with the classic bow-and-arrow (or target) diagram that illustrates the difference between precision and accuracy.

    I recreated Horton’s diagram on this topic because it effectively highlights that our ultimate goal in surveying is to reduce uncertainty in our results.

    As the diagram shows, simply repeating observations can give the appearance of good precision, but it does not guarantee accuracy. The result can be high precision with low accuracy — and therefore a large remaining uncertainty.

    Precision vs. Accuracy

    Recreated from Todd Horton presentation

    Todd noted that most RPP values are derived from a properly weighted least-squares adjustment. Many manufacturers’ software packages now use least squares to estimate RPP, making it essential to provide accurate error estimates so the data are correctly weighted in the adjustment.

    To illustrate this point, he provided clear examples of the following concepts:

    • Determining the appropriate error estimates for data,
    • Measuring errors,
    • Degrees of freedom and redundancy,
    • Significance and confidence intervals,
    • Appropriate weights of measurements,
    • Propagation of errors, and
    • Statistical tests for analysis of data and results. 

    He explained how to compute the allowable RPP and offered practical advice on selecting the appropriate equipment and measurement methods, tailored to the accuracy requirements of the project.

    In my opinion, this topic can be challenging to grasp without a strong mathematical background. Todd did an excellent job explaining the concepts clearly while avoiding excessive mathematical detail.

    To illustrate the RPP, Todd presented two real-world examples of combined networks using GNSS and traverse data. The first example combined GNSS with an open traverse using EDM, horizontal, and zenith angles. The second example incorporated RTK GNSS vectors with a closed traverse using classical survey data.

    This was an excellent session. I highly recommend reaching out to Todd for more details about his programs and insights.

    I want to thank the organizing committee of the 2026 SLSI Annual Meeting for the kind invitation to participate in their conference. I truly enjoyed the experience and came away with many valuable insights from this excellent gathering of surveyors.

  • 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. 

  • How to defeat harmful GPS/GNSS interference: A roadmap for action

    How to defeat harmful GPS/GNSS interference: A roadmap for action

    As GPS World readers know, the growing prevalence of GPS/GNSS jamming and spoofing outside of conflict zones interrupts vital aviation safety technologies and presents challenges to maritime commerce and the global economy. An alarming example is playing out along the Baltic Sea and the North Sea, prompting 13 coastal European nations and Iceland to highlight in January 2026 “growing GNSS interference” and collectively reinforce requirements to comply with existing regulations and international law designed to ensure the safety of all maritime vessels engaged in shipping.

    As commercial aircraft report navigation anomalies and maritime operators experience false position data in congested waterways, global authorities are sounding alarms that GNSS interference will continue to rise without immediate action. In March 2025, the International Civil Aviation Organization (ICAO), International Telecommunication Union (ITU), and International Maritime Organization (IMO) issued a joint warning expressing “grave concern” that disruptions from GNSS jamming and spoofing constitute an urgent threat to public safety, telecommunications networks and international commerce.

    Compounding harmful interference incidents led the GPS Innovation Alliance (GPSIA) to act. Defeating illegal and harmful interference outside of combat zones requires a coordinated, whole-of-government strategy that focuses on stopping bad actors through deterrence and enforcement, and directing resources toward preventing and sanctioning those violating international commitments and laws prohibiting jamming and spoofing. Investing in GPS modernization and integrating innovative signals from complementary PNT satellite systems into devices and receivers will deliver PNT that surpasses today’s technologies to the global community.

    Roadmap for Action

    In September 2025, GPSIA led a coalition of leading industry groups in sending a letter to the Departments of Defense and Transportation that called for urgent action to address GPS jamming and spoofing. We noted the United States has the technology and expertise to solve this issue, and the administration has the power to act. GPSIA followed the letter with a whole-of-government strategy providing a clear roadmap for the administration. While some recommendations have been implemented, other opportunities remain. 

    Focus on the Real Culprits 

    The culprits in each of these scenarios are bad actors putting public safety and global commerce at risk with harmful interference outside conflict zones. The global community relies on several unique technologies that can be impacted by harmful interference, such as cellular and Wi-Fi signals, radars and automated information systems. The misplaced focus on faint GNSS signals or dependencies on GNSS derail collective efforts to immediately regain interference-free global commerce and bolster public safety. 

    Governments and international organizations mandate certain industries integrate safety-of-life technologies into their operations — and they do, at great cost. Officials should in turn be given the political support and resources to stop bad actors from
    intentionally interfering with them.

    What to Do Next 

    Public and continued diplomatic engagement are critical. By amplifying European counterparts, condemnations from senior U.S. officials can raise the reputational costs for bad actors and reaffirm international norms that protect GNSS signals and other technologies from harmful interference. 

    Engaging with the ICAO is important. The U.S. should reinforce its commitment to providing modern civil GPS signals that support navigation in international airspace and encourage ICAO to prioritize the enforcement of global GNSS protections. 

    GPSIA also recommends Executive agencies establish an interagency task force that rapidly identifies and disseminates information about interference events with civil operators, including sanitized intelligence information on intentional jamming and spoofing of commercial aircraft and ships.

    Civil operators also should be invited to participate in interference coordination calls and reporting. Sharing radio-frequency interference data, incident reports and threat assessments among military and civil agencies and operators is essential to preserving public safety. The Performance-based Operations Aviation Rulemaking Committee’s recommendations for continuity of operations during GPS disruption events should continue to be implemented with urgency.

    The GPS III satellite has additional anti-interference features. (Image: Lockheed Martin)
    The GPS III satellite has additional anti-interference features. (Image: Lockheed Martin)

    Deterrence and information sharing must be coupled with sustained enforcement. Federal agencies have taken welcome action to interdict illegal jamming equipment, reporting an 830% increase in seizures since 2021. We applaud the U.S. government for prioritizing resources to stop the illegal import and sale of these devices.

    GPSIA commends the Kingdom of Norway’s annual Jammertest, which allows receiver and device manufacturers to test interference detection and counter jamming and spoofing. These realistic test scenarios, together with strengthened enforcement and prioritized intelligence collection and analysis, will enhance public safety.

    Modernize GPS 

    While GPS satellites continue operating with an extraordinary 99.99% availability and no outages on record, the health of the constellation and jamming and spoofing incidents affecting receivers and devices, demand action. The final GPS III satellite is scheduled to launch this spring. Next-generation GPS IIIF satellites are being built. Their launches should be prioritized to reduce the number of satellites on orbit that are one system or subsystem away from failure. GPSIA welcomed the passage of the FY2026 Defense Appropriations Bill, which bolstered national and economic security by investing needed funding for modernized GPS IIIF satellites and long-term PNT leadership. 

    Notably, the current GPS program plan does not include counter-spoofing technologies. Implementing counter-spoofing authentication capabilities for Wide Area Augmentation System (WAAS) signals would further strengthen aviation resilience.

    Ground infrastructure modernization is equally important. The GPS ground station must be able to command and monitor GPS III and IIIF satellites and the modern L5 aviation signal.

    Streamline Regulatory Activities 

    Regulatory modernization represents another area of progress. In September 2025, the State Department removed jam-and spoof-resistant Controlled Reception Pattern Antennas (CRPAs) from the International Traffic in Arms Regulations (ITAR), fulfilling one recommendation from GPSIA’s strategy. 

    Certification processes also must evolve, and integration of CRPAs into aircraft should be accelerated. The modern L5 signal and counter spoofing signal authentication signals must be incorporated into FAA-certified and other receivers as soon as possible. 

    Recommendations for the FCC 

    President Trump’s December 2025 Executive Order (EO), “Ensuring American Space Superiority,” directs U.S. departments and agencies to detect and counter threats to U.S. space infrastructure. It also states that his administration will enable industry to develop and deploy advanced space capabilities, including terrestrial and cislunar PNT applications. This EO should serve as a “North Star” for the FCC, resulting in increased enforcement resources to address illegal jamming and spoofing, and a regulatory environment prioritizing innovative, advanced commercial satellite PNT systems that complement GPS. Demonstrating American leadership in space demands that we step forward, not backwards, in our PNT capabilities.

    The FCC is evaluating the record developed in its Notice of Inquiry, Promoting the Development of PNT Technologies and Solutions, and is reportedly considering future rulemaking. The FCC’s task is not to replace GPS, but to ensure that the regulatory environment protects its spectrum, increases enforcement actions against those perpetuating harmful interference and enables innovation that complements this foundational system. This balanced approach will fulfill President Trump’s mandate, preserving public safety and economic security, and ensure continued American leadership in PNT.

    Global Safety and Commerce 

    Baltic and North Sea shipping lanes have become a flashpoint for GPS jamming and spoofing, prompting 13 European nations and Iceland to issue a joint warning in January 2026 over interference threatening maritime safety and global commerce. (Photo: Dmitri Toms / iStock / Getty Images Plus / Getty Images)
    Baltic and North Sea shipping lanes have become a flashpoint for GPS jamming and spoofing, prompting 13 European nations and Iceland to issue a joint warning in January 2026 over interference threatening maritime safety and global commerce. (Photo: Dmitri Toms / iStock / Getty Images Plus / Getty Images)

    The FCC’s Notice of Inquiry uncovered dozens of PNT technologies, ranging from those in the marketing stage, to hyper-localized solutions, to proposals to exploit “signals of opportunity.” Creativity and ingenuity abound in the commission’s record, but the docket’s many filings lacked technical details to evaluate whether the systems advance the nation’s
    PNT leadership.

    The hallmarks of GPS are its worldwide coverage, and the continuity, availability, integrity and accuracy of its signals. Our modern global community deserves complementary PNT systems and signals that meet or exceed GPS capabilities. A few satellite-based solutions stood out as holding promise to do so. 

    Systems operating in low-Earth orbit (LEO) can transmit stronger signal power due to their proximity to Earth, improving performance in urban environments and contested spectrum conditions. Systems operating in different frequency bands, such as TrustPoint’s C-band system, add spectral diversity, making it far more difficult for an adversary to disrupt all PNT services simultaneously. When combined with modernized GPS signals and authentication capabilities, this layered approach can deliver robust services while complementing the foundational role of GPS.

    Terrestrial systems cannot replicate global coverage of satellite constellations. They are also vulnerable to wildfires, hurricanes and other disasters.Building parallel terrestrial networks would require significant investment while delivering a fraction of modernized satellite systems’ capabilities. Nor do terrestrial signals provide the continuity, availability, integrity and accuracy of satellite systems. 

    The Progress is Real

    GPSIA is pleased to report that progress is being made in several areas outlined in its “whole-of-government” strategy. It’s time to accelerate that progress. In May 2026, GPSIA members will convene to evaluate this strategy and outline what more the PNT industry can do to play a part in defeating harmful interference. Our members also will meet with government officials to underpin that government-led enforcement and solutions to jamming and spoofing can further illustrate the importance of PNT to U.S. leadership in space, and national security, public safety and the global economy. 

  • Hybrid RTK: A scalable path to high‑precision positioning for the IoT era

    Hybrid RTK: A scalable path to high‑precision positioning for the IoT era

    The world is rapidly filling with connected devices. IoT Analytics reports that 18.5 billion IoT devices were online in 2024, with growth accelerating toward an expected 21.1 billion by the end of 2025 and 39 billion by 2030. As artificial intelligence drives demand for richer, more precise device data, the need for reliable, high‑accuracy positioning becomes foundational.

    Yet today’s GNSS infrastructure — including cellular-based real‑time kinematic (RTK) networks — was never designed for this scale. Billions of devices — from vehicles to drones to industrial sensors — depend on location data, but the traditional GPS model struggles under three converging pressures: (1) massive device growth, (2) rising accuracy requirements, and (3) increasing vulnerability to interference.

    These pressures are reshaping expectations for positioning, navigation and timing (PNT) and creating demand for a new, more resilient delivery model.

    Why Accuracy and Resilience Matter More Than Ever

    Autonomous systems are the clearest example of the accuracy challenge. Xona Space Systems CTO Dr. Tyler Reid notes that safe autonomous driving requires 10 cm accuracy 95% of the time and 30 cm accuracy at “eleven nines” reliability. Standard GPS, accurate only to several meters, cannot meet these thresholds — even with traditional enhancement techniques.

    At the same time, GNSS signals face growing threats. Spoofing and jamming events are now daily occurrences in parts of Europe, and U.S. federal agencies increasingly require contract bidders to incorporate resilient PNT technologies alongside legacy GNSS.

    Finally, the explosion of IoT devices introduces a network‑scale challenge. Many of these devices could benefit from high‑precision positioning, but continuous unicast RTK streams are not an efficient use of cellular networks, especially as billions of devices come online.

    Together, these factors point to a simple conclusion:

    A new delivery model for high‑precision GNSS corrections is needed — one that is accurate, resilient, and scalable.

    Why a Hybrid Approach Is Required

    RTK positioning is the gold standard for centimeter‑level accuracy. It works by combining GNSS signals with correction data from a known base station. However, traditional RTK has two major limitations:

    1. Coverage constraints — corrections must be delivered within a limited range of the base station due to the fact that accuracy diminishes the further the GNSS base is from the rover.
    2. Network constraints — corrections are typically delivered over cellular networks, which become inefficient at scale.

    Precise Point Positioning (PPP‑RTK) can extend range and reduce dependency on local base stations, but today’s PPP‑RTK implementations are proprietary and lack a common standard.

    To support billions of devices — many mobile, many mission‑critical — the industry needs a correction‑delivery model that is:

    • Nationwide
    • Efficient at scale
    • Resilient to interference
    • Cost‑effective for high‑volume IoT deployments

    This is where hybrid RTK becomes essential.

    Introducing Hybrid RTK: A Dual‑Path Delivery Model

    Hybrid RTK refers to the dual‑path delivery of GNSS correction data, consisting of:

    • Primary path: ATSC 3.0 broadcast
    • Fallback path: Cellular (LTE/5G)
    • Upstream messaging: Cellular for acknowledgments or device telemetry

    Compared to a satellite-based RTK solution or even a cellular-only RTK solution, hybrid RTK will deliver corrections over a far more reliable and scalable network, because it’s both broadcast and terrestrial-based.

    Why broadcast first?

    ATSC 3.0 provides:

    • One‑to‑many multicast efficiency
    • Predictable capacity and uniform latency
    • Wide coverage footprints
    • Strong penetration in dense urban environments
    • Lower cost per delivered bit

    This makes it ideal for distributing high‑precision correction data to large numbers of devices simultaneously — something cellular networks are not optimized for.

    Why cellular second?

    Cellular fills in:

    • Coverage gaps where ATSC 3.0 is not yet deployed
    • Uplink needs (e.g., device status, position feedback)
    • Mobility scenarios requiring two‑way communication

    The result is a resilient, nationwide correction layer that scales with IoT growth.

    EdgeBeam Wireless: A New Entrant with a Broadcast‑First Architecture

    EdgeBeam Wireless is deploying a hybrid RTK network that leverages the existing infrastructure of U.S. television broadcasters — including secure facilities, hardened towers, and nationwide engineering resources — for both over-the-air RTK delivery and collocating GNSS base stations.

    This approach provides several advantages:

    • Accelerated deployment of GNSS base stations designed to complement existing base networks.
    • Lower infrastructure costs than cellular‑only RTK networks.
    • High reliability through broadcast delivery.
    • Scalable distribution for dense IoT environments.
    • Nationwide reach as ATSC 3.0 coverage expands.

    EdgeBeam’s broadcast‑first model — branded by the company as  “Enhanced GPS” or  “eGPS” — is best understood simply as hybrid RTK with broadcast as the primary downlink. While this hybrid approach does require some additional hardware to receive the broadcast, pricing is already very competitive to cellular because these chips will be found in every television set in the country. Moreover, EdgeBeam already has products available for end users that want to leverage a hybrid network without having to do any development work.

    Broadcast RTK: A New Network Layer at the Edge

    Broadcast RTK uses ATSC 3.0 to distribute GNSS correction data over the last mile. This creates a new edge network layer that can support both GNSS and other data applications, including:

    • High‑precision GNSS corrections
    • Multicast distribution of positioning data
    • Offloading of appropriate high‑volume traffic (e.g., video) from cellular networks
    • Enterprise‑grade reliability for industrial and transportation systems

    By shifting the heavy downlink load to broadcast, cellular networks are freed to handle uplink messaging and mobility support — a more efficient division of labor.

    This hybrid architecture is not just about improving individual device accuracy. It enables something more powerful.

    A New Generation of Shared Situational Truth

    When many devices operate on the same centimeter‑accurate reference frame at the same time, a new capability emerges: Shared Situational Truth (also known as shared situational awareness).

    This refers to a consistent, real‑time understanding of location and timing across a fleet, system, or environment. Hybrid RTK enables this by delivering synchronized, high‑precision PNT to large numbers of devices simultaneously. By offloading RTK delivery to a broadcast network, cellular and other communication networks can then be used to share a device’s position and other data with other local devices.

    What is being shared?

    • Precise location
    • Precise timing

    Who is sharing it?

    • Vehicles
    • Fleets
    • Drones
    • Industrial robots
    • Infrastructure sensors
    • Emergency services
    • Insurance and logistics platforms

    What does it enable?

    Examples include:

    • Safer ADAS/ADS through lane‑level awareness
    • Collision avoidance for drones and autonomous systems
    • Fleet optimization using precise, time‑aligned movement history
    • Improved insurance models through reliable behavior measurement
    • Faster accident resolution with time-synchronized location records
    • Infrastructure‑to‑vehicle coordination for road hazards or construction zones

    In transportation alone, EdgeBeam’s hybrid RTK solution could make entire traffic systems safer and more predictable — not just individual vehicles.  And importantly, this can be done far more efficiently than via just a cellular-based solution.

    Conclusion: A Foundational Shift in PNT Delivery

    The convergence of IoT growth, accuracy demands, and GNSS vulnerabilities is forcing a rethinking of how high‑precision positioning is delivered. Hybrid RTK — with broadcast as the primary downlink and cellular as a complementary path — offers a scalable, resilient, and cost‑effective solution.

    For industries ranging from automotive to logistics to public safety, the shift from “nice‑to‑have” to “must‑have” high‑precision PNT is already underway. As hybrid RTK networks expand, the ability to deliver centimeter‑level accuracy at scale will unlock new applications, new efficiencies, and new expectations for how devices understand and interact with the world.

    EdgeBeam Wireless is building this new correction layer — one designed for the billions of devices that will depend on precise, reliable positioning in the years ahead.

  • UAV updates: Attack drones deployed in the Iran conflict and autonomous boats at RoboBoat 2026

    UAV updates: Attack drones deployed in the Iran conflict and autonomous boats at RoboBoat 2026

    The war between Israel, the United States and Iran has dominated headlines since it began with surprise attacks launched by Israel and the U.S. on the last day of February. Significant damage has since been inflicted on Iran as the allies seek to end the country’s nuclear capabilities and bring about regime change — removing those responsible for worldwide terrorism through its proxy groups, including Hezbollah, the Houthi movement in Yemen, various Iraqi Shiite militias, Hamas and Islamic Jihad, all of which have targeted Western countries and Israel.

    Iran maintains a formidable military with more than 600,000 active-duty personnel, an estimated 2,000 to 3,000 ballistic and shorter-range missiles, and a significant offensive drone capability. The Shahed series and Mohajer-6 drones have emerged as low-cost kamikaze weapons central to Iran’s arsenal. The Shahed-136 in particular has been supplied in large quantities to Russia for use in its ongoing war against Ukraine and is now also manufactured by Russia, or a version of it is. The Shahed drone has several variants, including the jet-powered, long-range Shahed-238.

    Iranian Shahed-136 attack drones, read for launch. (Photo: IMA Media)
    Iranian Shahed-136 attack drones, read for launch. (Photo: IMA Media)

    With a range of 800 miles to 1550 miles, the Shahed-136 carries an 88-pound warhead which can punch very large holes in buildings, disable oil tankers or warships, destroy equipment on the ground, and kill and injure lots of personnel. It’s possible that those six US servicemen killed and others injured during the early hours of the conflict in Port Shuaiba, Kuwait, were victims of a Shahed kamikaze drone attack.

    This is not all bad news: the U.S. has analyzed captured downed Shahed-136 drones and has quickly replicated its own version, the Low-cost Unmanned Combat Attack System (LUCAS), admittedly with a shorter range but just as deadly. It’s reported that the Iranians can build and mass-produce thousands of drones for between $20 and $50,000 each. Nevertheless, the U.S. has now been producing large volumes of LUCAS, and has them to fight in Iran.   

    LUCAS is already in US volume production. (Photo: US Central Command)
    LUCAS is already in US volume production. (Photo: US Central Command)

    Spektraworks, based in Phoenix, was awarded a $30 million contract, and within 18 months, a redesigned, hardened and autonomously coordinated attack drone — manufactured in the U.S. at a cost of approximately $43,000 per unit — became available in significant quantities and was fielded to U.S. Central Command’s newly formed drone task force, Task Force Scorpion Strike.

    The unit was responsible for the Shahed-like drones seen flying over Baghdad in early television coverage as the U.S. offensive got underway.

    It marks a notable achievement — delivering similarly designed attack drones, and the destruction they carry, back to Iran, a country that has exported terror to numerous nations for more than 50 years.

    Meanwhile, the 2026 RoboBoat Competition took place at Nathan Benderson Park near Sarasota, Florida, drawing 37 high school and university teams. The event challenges students to demonstrate progress in developing autonomously operating marine systems installed on model boats. Benderson Park features a large rowing lake that has hosted Olympic rowing and canoe trials, making it a fitting venue for RoboBoat competitors and spectators.

    Teams arrived with a wide variety of model boat designs and technical approaches, navigating through a series of in-water obstacle courses while gaining hands-on experience relevant to future careers. Volunteer support was plentiful, and each team brought cheering crews and technical assistance. Typical tasks included restoring simulated harbor operations, assessing underwater infrastructure and supporting exploration scenarios.

    After watching more than 2 hours of posted videos, it is clear that the competition is run by a volunteer student organization. The final-round objectives were not clearly defined, and without commentary, it was difficult to determine whether any team successfully completed the obstacle course — though several boats did navigate between narrow red and green buoys after avoiding a series of posts in the water.

    RoboBoat 2026
    RoboBoat 2026

    Nevertheless, it was great to see the whole gathering, many from overseas, and the level of enthusiasm. One guy told the story of how the team’s heavy equipment had survived a long-distance shipment from overseas and arrived almost intact. But during the competition, the quite heavy demo boat sank; it was just a minor setback for him — we’ll learn something and keep going!  — was his mantra. As everyone in the industry knows, having your tested, verified, and 100% reliable set-up actually function at a trade show is a major hurdle we’ve all had to overcome. So, it’s good to see these young men and women learn firsthand what it takes to get a prototype to work when it becomes absolutely essential – and of course, to actually make progress and extend their reach towards autonomous robotics.

    The U.S. military has been throwing Shahed-like kamikaze weaponized drones back at the country that had not only invented them, but also spread the technology to and through other antagonists, yet now feeling their impact on their own capital city — a significant success for the initial U.S. attack on Iran. And growing and supporting the latest wave of students and their autonomous aspirations at RoboBoat 2026 in Florida. One aspect of UAVs is warlike and deadly, while another is encouraging young engineering candidates towards their dreams of maritime robotic autonomy.

  • NGS presents the latest NSRS news at Geo Week 2026

    NGS presents the latest NSRS news at Geo Week 2026

    In my January 2026 GPS World newsletter, I noted that the National Geodetic Survey (NGS) convened the Federal Geodetic Control Subcommittee (FGCS) meeting with federal geospatial agencies to boost awareness and align efforts on National Spatial Reference System (NSRS) Modernization government-wide. Key steps include cultivating internal champions to champion the initiative, distilling complex topics for clear leadership briefings, and bringing together agencies, partners, and industry to collaboratively shape solutions. I also highlighted that on Feb. 17-18, NGS staff would be participating in Geo Week 2026 in Denver to engage geospatial product and service users and further coordinate on the modernization. NGS gave several presentations during GeoWeek that addressed many of my questions on the new modernized NSRS. This newsletter will highlight some of NGS’s presentations.

    First, a special shout-out to my dear friend and former colleague, Juliana Blackwell, retired Director of the National Geodetic Survey. NOAA’s Table Mountain Gravity Observatory in Boulder, Colorado — long known for its absolute gravity work — has been officially renamed the J. P. Blackwell Gravity Observatory. This well-earned tribute honors her outstanding dedication and visionary leadership at NGS. Congratulations, Juliana!

    J. P. Blackwell Gravity Observatory. (Photo: NGS)
    J. P. Blackwell Gravity Observatory. (Photo: NGS)
    J. P. Blackwell Gravity Observatory. (Photo: NGS)
    J. P. Blackwell Gravity Observatory. (Photo: NGS)
    J. P. Blackwell Gravity Observatory. (Photo: NGS)
    J. P. Blackwell Gravity Observatory. (Photo: NGS)

    NGS employees participated in the following sessions and meetings during GeoWeek 2026:

    • ASPRS NSRS Modernization Working Group Meeting
    • NSRS Modernization — The Latest Technical Updates
    • Preparing to Put the Modernized National Spatial Reference System into Practice
    • Roundtable — NSRS Modernization and Professional Societies

    As President of the American Association for Geodetic Surveying (AAGS), I participated in the session titled “Roundtable – NSRS Modernization and Professional Societies.” Dana J Caccamise II, NGS regional geodetic advisor, opened our session by describing the NGS Modernization Engagement Plan and Progress.  As I mentioned last month, Dana should get an award for the material he has prepared and for his work assisting agencies and professional organizations in preparing for the new NSRS. I highlighted Caccamise’s work in my October 2025 GPS World newsletter.

    All the NGS sessions provided the latest information on activities associated with NGS’s NSRS Modernization. Here are the specific questions I had going into the session, along with the clear answers provided by NGS personnel during their presentations and the follow-up Q&A:

    What NGS products and services will be available when federal agencies officially adopt the new NSRS?

    When the modernized NSRS is officially adopted (following FGCS approval and the transition to it becoming “the NSRS”), NGS will make available a full suite of updated tools, data access points, and services built around the new reference frames (e.g., NATRF2022 and variants), the North American-Pacific Geopotential Datum of 2022 (NAPGD2022), the State Plane Coordinate System of 2022 (SPCS2022), and associated geopotential models like GEOID2022. Key products expected to be operational and official include:

    • NCAT
    • NGS Maps
    • Geodetic Station Page
      • CORS
    • Geodetic Mark Page
      • Passive Marks
    • OPUS–Static 5.2
    • OPUS-Share

    What NGS products and services will NOT be available when federal agencies officially adopt the new NSRS?

    Upon official adoption of the modernized NSRS — after FGCS approval and the shift to the new system becoming “the NSRS” — several current products and services will no longer be part of the official modernized NSRS or will be discontinued in their present form. Key items not included or no longer supported in the modernized NSRS release include:

    • OPUS Projects 5 will not be supported
      • OPUS-Rapid Static (OPUS-RS) will not be supported (modernized OPUS-Static 5.2 is expected to handle a broader range of observations)
      • OPUS 6.0 and OPUS 6.1 will not be available

    What GNSS data will be included in the first iteration of the computation of Reference Epoch Coordinates (REC) for marks?

    At Geo Week 2026, NGS stated that its plans include providing Reference Epoch Coordinates (RECs) for certain legacy GNSS projects. Specifically, this includes:

    • GPS projects that were originally processed and published under the NAD 83 (2011) realization, and
    • Other GNSS projects will be officially published by NGS through the end of 2025\

    After the first iteration of Reference Epoch Coordinates, is NGS planning to perform future adjustments to determine REC and SEC of new marks? If so, what process will be used to establish RECs on new marks?

    Yes, NGS plans include performing future adjustments to compute Reference Epoch Coordinates (REC) for new marks. However, at this time, no final decision has been made on how often this will be performed.

    Has NGS changed how users need to submit data to incorporate leveling data into NAPDG2022?

    Yes, NGS has introduced changes to better integrate leveling data (differential height differences) into the modernized NSRS for computing orthometric Reference Epoch Coordinates (RECs) in NAPGD2022 (epoch 2020.00).

    As documented in Blueprint Document 3, when performing leveling projects, users will also be required to occupy a number of primary marks with GNSS.

    OPUS 6.1 is built for future expansion to support other geodetic measurements (classical, leveling)-no timeframe was given for this.

    Is NGS planning to officially adopt the new NSRS before users can submit data to NGS for technical review and publication in the NGS database?

    Yes, that is what NGS is saying at this moment (February 2026). OPUS Project 5 will not be supported and OPUS 6.1 will not be operational when the new NSRS is officially adopted.NGS is working on the OPUS 6 application and is trying to “minimize any gap in service.”

    Is NGS recommending using the OPUS-Share utility until users can submit data to NGS for technical review and publication in NGS database?

    Yes, that is what NGS is recommending at this moment (February 2026). 

    This is also stated in NGS’s Track Our Progress Webpage.

    OPUS-Projects 5 will not be included in the modernized NSRS. Instead, NGS will focus on both developing an improved software suite for OPUS, known as OPUS 6.0 and OPUS 6.1, and minimizing any gap in service in which the current OPUS-Projects functionality is not available for users to organize, process, adjust, and submit high-accuracy GPS surveys for use by NGS in expanding and improving the NSRS. As noted above, OPUS-Share will remain available as a means to submit data to NGS.

    When will OPUS 6.1 be available for users to submit data to NGS for technical review and publication in NGS database?  Is it weeks away, months away, or years away?

    NGS has not announced an official completion or release date for OPUS 6.0 and OPUS 6.1. However, they have indicated that active development is underway on this enhanced OPUS tool suite.  It’s not imminent— meaning not expected within several months—but it’s also not a distant, multi-year project.

    NGS is working on the application and is trying to “minimize any gap in service.”

    The NGS’s Track Our Progress Webpage states:

    “OPUS-Projects 5 will not be included in the modernized NSRS. Instead, NGS will focus on both developing an improved software suite for OPUS, known as OPUS 6, and minimizing any gap in service in which the current OPUS-Projects functionality is not available for users to organize, process, adjust, and submit high-accuracy GPS surveys for use by NGS in expanding and improving the NSRS. As noted above, OPUS-Share will remain available as a means to submit data to NGS.”

    What’s the cut-off date for users to submit projects via OPUS Project 5 so the data can be part of future computations of RECs?

    Current OPUS-Projects 5 is going to be supported until adoption of the new NSRS, with a deadline announced at least 6 months in advance.

    The NGS’s Track Our Progress Webpage states

    “Note: the current OPUS Projects 5 software will be supported until the modernized system is adopted, and a deadline for OPUS-Projects users to submit their surveys for publication will be announced with at least six months’ notice.”

    In the session “NSRS Modernization – The Latest Technical Updates,” the National Geodetic Survey (NGS) presented slides detailing the status and upcoming tasks for the modernized National Spatial Reference System (NSRS).  Key highlights from the presentation are summarized below.

    For the source of these slides and additional context, refer to the “Updates from the National Geodetic Survey at GeoWeek 2026” box.  NGS posts their presentations at here: https://geodesy.noaa.gov/web/science_edu/presentations_library/.

    Updates from the National Geodetic Survey at GeoWeek 2026

    (Selected Slides from the following presentations)

    • 2026 GeoWeek – NSRS Modernization – The Latest Technical Updates: The Why and How of NSRS mod – February 17, 2026 – Dru Smith
    • 2026 GeoWeek – Managing Modernization Rollout – February 17, 2026 – Seth Pollack
    • 106th Wyoming Engineering and Surveying (WES) Society Conference – February 5, 2026 – Brian Shaw
    • 2026 GeoWeek – Modernized Tools – February 17, 2026 – Brian Shaw

    2026 GeoWeek –   Updates to OPUS for Accessing the Modernized NSRS – February 17, 2026 – Dan Gillins

    During Dru Smith’s presentation, he mentioned what will be included in the first iteration of the computation of Reference Epoch Coordinates (REC) for marks. The slide states that more than 150,000 geometric (XYZ) coordinates and 1 million geopotential coordinates (that is, orthometric heights) will get reference epoch coordinates (REC), epoch 2020.00.  These will include data from NGS Integrated Database and from the OPUS Share database.

    First Reference Epoch Coordinates (REC). (Presented at GeoWeek 2026)
    First Reference Epoch Coordinates (REC). (Presented at GeoWeek 2026)
    First Reference Epoch Coordinates (REC). (Presented at 106th WES Society Conference)
    First Reference Epoch Coordinates (REC). (Presented at 106th WES Society Conference)

    In the GeoWeek 2026 presentation by Seth Pollack (from NOAA’s National Geodetic Survey), a slide outlined the NSRS modernization timeline.

    As detailed in the slide and consistent with NGS’s official rollout plan:

    • Beta products are currently being released incrementally on the beta site for public testing and feedback. This phased rollout began with initial beta releases in 2025 (following alpha in 2024) and continues through 2026, covering key components such as NAPGD2022, GEOID2022, SPCS2022, enhanced NCAT transformation tools, OPUS-Static updates, and forthcoming Data Delivery System features.
      • Each beta component, once released, undergoes public testing and stakeholder feedback, with overall testing continuing for at least 6 months after the final component is made available on the beta site.
    • Following sufficient testing—once all components appear stable and NGS has incorporated feedback—the Federal Geodetic Control Subcommittee (FGCS) will vote to recommend approval of the modernized NSRS. This vote is anticipated in late 2026 or early 2027.
    • Upon FGCS approval (and subsequent Federal Geographic Data Committee (FGDC) endorsement), NGS will probably publish a Federal Register Notice announcing the adoption.  At that point, the modernized NSRS becomes the official National Spatial Reference System, replacing the legacy system (NAD 83 realizations, NAVD 88, etc.).
      • While earlier NGS documentation targeted adoption likely in mid-to-late 2026 (post-FGCS vote), recent updates from GeoWeek 2026 sessions and related reports indicate the full official adoption and transition may extend into the first part of 2027, accounting for final testing, FGCS/FGDC processes, Federal Register steps, and a smooth handover to avoid disruptions.
    • The current NSRS remains official throughout this period. Users are encouraged to test beta products now and provide feedback to help refine the system.
    NSRS Modernization Timeline. (Presented at GeoWeek 2026)
    NSRS Modernization Timeline. (Presented at GeoWeek 2026)

    Brian Shaw, NGS’s expert on GIS products and services, presented key updates on how users will access geodetic data in the modernized National Spatial Reference System (NSRS).

    He emphasized the introduction of a revamped Data Delivery System (DDS), which includes:

    • Geodetic Mark Pages — for passive marks. These replace the current ASCII-text datasheets with modernized, user-friendly pages featuring updated Reference Epoch Coordinates (RECs), integrated photos, graphics, maps, project details, and easier navigation.
    • Geodetic Station Pages — for active stations like those in the NOAA CORS Network (NCN). These provide updated versions of existing CORS pages, including modernized coordinate functions (e.g., Coordinate Functions or time-dependent positioning info) aligned with the new reference frames (NATRF2022, etc.).
    • Additionally, Shaw highlighted a new interface for the NGS Map (the interactive web map application), serving as an enhanced landing page within the DDS. This updated “NGS Map” (replacing or evolving the current version at https://noaa.maps.arcgis.com/apps/webappviewer/index.html?id=190385f9aadb4cf1b0dd8759893032db ) will provide better access to geodetic control data, CORS stations, and other layers, improving visualization and querying for surveyors, GIS professionals, and the public.
    • These changes are part of the broader DDS rollout, currently pending beta release (as of February 2026), aimed at making data more accessible, visually rich, and compatible with the modernized NSRS components (e.g., NATRF2022, NAPGD2022, SPCS2022). The DDS landing page will consolidate access, moving away from legacy datasheet formats toward dynamic, web-based delivery.
    Accessing Data from NGS. (Presented at GeoWeek 2026)
    Accessing Data from NGS. (Presented at GeoWeek 2026)
    Accessing Data from NGS. (Presented at GeoWeek 2026)
    Accessing Data from NGS. (Presented at GeoWeek 2026)
    Accessing Data from NGS. (Presented at GeoWeek 2026)
    Accessing Data from NGS. (Presented at GeoWeek 2026)

    During Dan Gillins presentation he highlighted that NGS has three development phases for OPUS underway to support the Modernized NSRS:

    OPUS-S 5.2: Multi-GNSS with similar functionality as current OPUS-S

    • Occupations – one hour or greater
    • Standard deviations estimate instead of peak-to-peak values

    OPUS 6.0: Rewrite of code base in cloud-native application

    • single/multiple occupations on a single mark
    • enhanced sharing functionality
    • Occupation Time – minimum of 4 hours
    • NGS will review and add these data to the next reference epoch coordinate (REC) adjustment

    OPUS 6.1: Extension of OPUS 6.0 for multiple marks in a network

    • Replace OPUS-Projects functionality
    • Multiple occupations on a network of marks (campaign-style surveys)
    • Will allow multiple occupations on a single mark – uploads ~10 data files on a mark
    • Built for future expansion to support other geodetic measurements (classical, leveling)

    I want to emphasize that, in my opinion, NGS is doing a fantastic job with the limited resources that they have.  That said, I still have an issue with adopting the new NSRS without having a process for users to submit data to NGS for review, approval, and publication by NGS.  This may not be an issue if NGS’s OPUS 6.1 is available soon after the new NSRS is adopted by the Federal Agencies.

    My August 2025 GPS World Newsletter discussed the OPUS products under development and, as I mentioned at that time, in my opinion, may be a problem for some users.  As I stated in my August newsletter, for the new NSRS to be successfully implemented by users, it is essential that all the necessary software tools are available to enable users to submit projects for review, approval and publication by NGS. 

    Excerpt from August 2025 GPS World Newsletter

    “The NGS News announcement provides a list of products that will be available and a list of products that will not be available when the new NSRS is adopted. Users need to understand what products will not be available after NGS officially adopts the new NSRS so they can determine what that means to their workflow process and client requirements.  In my opinion, for the new NSRS to be successfully implemented by users, it is essential that all the necessary software tools are available to enable users to submit projects for review, approval, and publication by NGS.  As many of you know, when I worked for NGS, I was the Project Manager of the North American Vertical Datum of 1988 (NAVD 88). That said, from my experience as the NAVD 88 Project Manager, having the appropriate tools available was important for users to implement NAVD 88.  As a matter of fact, NGS accepted and processed vertical control data in both NGVD 29 and NAVD 88 for a period to assist users in the implementation of the new vertical reference datum.”

    NGS does state that users will be able to submit data through OPUS and OPUS Share to obtain estimates of coordinates in the new NSRS.  Unfortunately, using OPUS-Share results that are NOT official NSRS coordinates published by NGS could lead to confusing results and potential lawsuits since NGS does not stand behind the results and recommends NOT using OPUS-Share results for geodetic control.

    “This is NGS’s statement on OPUS-Share: Additionally, the popular function of “sharing” your solution with others (colloquially called “OPUS-Share”) will be retained, but with appropriate caveats that the shared solution should not be used as geodetic control. These shared solutions will be available through the geodetic mark pages of the DDS.“

    Why should users use OPUS-Share to establish geodetic control when NGS advises against relying on OPUS-Share for establishing geodetic control?  OPUS-Share results are not officially submitted to NGS for review, approval, and publication on an NGS Datasheet. I don’t believe this approach will meet the needs of users who require their projects to be reviewed, approved, and published by NGS.

    Finally, as someone deeply invested in the geodetic community—having retired from NGS and followed NGS developments closely for years—my overall opinion on the NSRS modernization rollout plan for the remaining products is cautiously positive, but with some genuine concerns that I believe NGS and stakeholders should address head-on to ensure a smoother transition.

    The phased beta release approach (starting in 2025 and continuing through 2026) is smart and user focused. Releasing components incrementally on the beta site, allowing at least 6 months of public testing and feedback per major piece (and overall testing extending beyond the final release), shows NGS is prioritizing stability over speed. The emphasis on stakeholder input, FGCS approval (now looking like late 2026 or early 2027), and a multi-month transition to the official site align well with best practices for such a massive shift. It’s encouraging to see private industry partners (e.g., ESRI, Blue Marble) already engaging deeply and planning implementations—success will depend on industry buy-in.

    That said, here are my main thoughts and concerns I’d share directly with NGS (perhaps via [email protected], user forums, or upcoming webinars/Q&A sessions):

    Timeline uncertainty: Clearer, more frequent milestone updates (beyond the Track Our Progress page) would help manage expectations. For example, monthly or bimonthly “status dashboard” with remaining beta items and projected release windows would be invaluable.

    OPUS and processing continuity: The shift away from OPUS-Projects 5 toward OPUS 6 and OPUS-Share is logical for a modern GNSS-centric system, but the lack of a firm end-of-support date for legacy OPUS tools (beyond “at least 6 months’ notice”) creates planning headaches for firms with ongoing projects. NGS should commit to a longer grace period—or ideally a defined parallel support window—for legacy OPUS tools (particularly OPUS-Projects 5) after the official adoption of the modernized NSRS.

    Data access and usability in the new DDS: The revamped Geodetic Mark/Station Pages, updated NGS Map interface, and overall Data Delivery System sound promising (more visual, integrated RECs/SECs, photos, etc.), but surveyors rely heavily on reliable, scriptable access (e.g., for bulk queries or automation). If the new web-based system lacks robust APIs or export options comparable to current datasheets/legacy tools, it could hinder efficiency. Beta testers should push hard on this during the 6+ month window.

    Transformation tools and legacy data handling: Enhanced web-based tools are key for bridging old-to-new (NAD 83/NAVD 88 to NATRF2022/NAPGD2022), but users need confidence that transformations minimize errors, especially in deformation-prone areas.

    Communication and outreach: NGS has improved with webinars, the Presentations Library, and beta feedback channels, and more targeted outreach to state agencies, professional societies (NSPS, AAGS), and software vendors has helped. That said, many in the field still feel “in the dark” about practical impacts—case studies, training resources, and FAQs tailored to common workflows would go far.

    In summary, the plan is thoughtful and deliberate, reflecting lessons from past delays. If NGS maintains transparency, incorporates feedback aggressively during beta, and ensures vendor readiness, the modernized NSRS will be a major win for accuracy, sustainability, and GNSS alignment.

    I’d encourage anyone reading this (including NGS staff) to test the beta products actively, submit detailed feedback, and participate in forums/Q&As. The community input will make or break the success of this once-in-a-generation update.

  • Building GNSS you can trust: Lessons from testing in Germany and Japan

    Building GNSS you can trust: Lessons from testing in Germany and Japan

    Crowded cities with stacked road systems and reflective architecture may offer impressive skylines, but for GNSS receivers, they create some of the harshest conditions on Earth. For technologies that depend on stable, trustworthy positioning, real-world testing in these challenging environments is essential. Here, Jez Ellis-Gray, product manager at Focal Point Positioning, a provider of GNSS positioning software, examines what recent field deployments reveal about the future of reliable GNSS.

    Urban environments present unique constraints that no laboratory or simulation can perfectly replicate. A lab test may miss the thousands of variables that influence signal behaviour in a living, breathing city or a dense forest road. This matters most for automotive applications, where positioning must remain stable and trustworthy to support driver assistance and higher levels of automation. That is why we conducted field trials across Germany and Japan, evaluating FocalPoint’s S-GNSS Auto software running on STMicroelectronics’ Teseo GNSS receivers in challenging real-world conditions.

    This testing demonstrated that GNSS performance in the real world is often determined not by peak accuracy under ideal conditions, but by the system’s reliability when satellite signals are distorted, reflected or partially obstructed.

    This distinction — between accuracy and reliability — is becoming increasingly important for sectors where positioning plays a safety-critical role, including automotive.

    Understanding the complexity of real environments

    Germany’s combination of modern architecture and medieval street layouts made it a good place to test GNSS upgrades against standard technology. A city like Frankfurt offers a nice mix of glass facades, narrow streets and tall buildings – conditions that tend to create multipath interference.

    During our recent field testing, conventional GNSS receivers frequently suffered from severe degradation of position accuracy when compared to a state-of-the-art ground truthing system. The standard receiver positions will often drift away from the travelled path, often through buildings or even onto parallel roads.

    As accuracy deteriorates, the receiver can usually tell that the input information is poor, and output a warning for a larger estimate of error.  This is a useful warning flag for AVs and allows for safe handover back to the human driver. However, in some cases, the reflected signals cause the miscalculation to be assumed correct. This “confident but wrong” GNSS is a much greater threat to autonomous driving, as the vehicle may make a dangerous decision based on this false information.

    In contrast, the S-GNSS Auto enhanced receiver was able to maintain lane-level accuracy far longer, even in areas where intense reflections would normally overwhelm the satellite data. In multipath-heavy environments, S-GNSS on Teseo receivers showed an accuracy improvement of up to 4x. These findings reinforced our belief that, as automation increases, consistency and reliability will be more valuable than peak accuracy.


    A navigation system that performs well on open motorways but struggles on urban roads will not scale safely to higher levels of vehicular automation. This is particularly relevant as the industry transitions from Level 2 to Level 3 autonomy, marking the point at which a vehicle takes full responsibility for the driving task in defined conditions, allowing the driver to disengage temporarily while the system manages safety-critical decisions.

    This shift is expected to unlock significant commercial value. A 2023 report by McKinsey predicted that advanced driver assistance and autonomous driving features could generate between $300 billion and $400 billion in annual revenue by 2035, driven by software services and subscription-based functionality that depend heavily on reliable positioning.  Unlocking this potential will depend on the next generation of vehicles having robust positioning systems, as users are unlikely to pay ongoing subscriptions to systems that repeatedly require human intervention or where safety concerns linger.

    Japan: one of the world’s most challenging environments

    If Germany represents a demanding test bed, Japan pushes GNSS to the extreme. Tokyo offers some of the toughest conditions anywhere in the world due to its towering buildings, multilevel road networks and narrow corridors that create intense multipath environments, so it was a natural choice for our next field test.

    The results showed that in particularly dense districts such as Shinjuku, standard GNSS receivers often struggled to maintain a coherent position solution. Reflections from glass towers, elevated highways and rail lines produced non-line-of-sight signals that overwhelmed conventional algorithms.

    S-GNSS Auto, integrated onto STMicroelectronics’ Teseo receivers, demonstrating improvements in vehicle positioning accuracy. (Data from Shinjuku, Tokyo)
    S-GNSS Auto, integrated onto STMicroelectronics’ Teseo receivers, demonstrating improvements in vehicle positioning accuracy. (Data from Shinjuku, Tokyo)

    However, receivers equipped with S-GNSS’s advanced signal-processing techniques demonstrated significantly improved performance. These upgraded devices maintained a stable positioning where traditional systems faltered, avoiding errors that would cause an automated system to disengage or provide dangerously erroneous positions

    This improved reliability has direct implications for safety and user experience, which vehicle OEMs will no doubt welcome. In driverless vehicles, GNSS problems that trigger sudden driver handovers or interruptions to hands-free modes, are likely to erode trust and reduce the likelihood of subscription renewals, as the end user will judge the product less by its peak performance and more by its dependability in everyday situations.

    Field testing and the future of positioning technology

    As cities evolve, buildings grow taller and mobility systems become more congested, the challenges facing GNSS will only increase. As such, automotive OEMs are rightly starting to demand real world results, not just in ideal conditions (static, open sky) but in the worst conditions.

    Manufacturers increasingly recognise that positioning is now a foundational technology that underpins safety, automation and customer experience. Investments in more reliable GNSS systems are therefore not marginal enhancements but essential enablers of future services. For companies developing navigation and sensing technology, real-world testing offers a unique opportunity to understand how systems react to chaotic, imperfect environments. It provides granular insight into where and why positioning fails, and how these software-based enhancements can bridge the gap. By validating these solutions in the world’s toughest GNSS environments, developers can offer manufacturers greater confidence in deploying advanced features across global markets.  

    You can request an evaluation kit here or download the full results report of our latest testing here.

  • The Hill: America is dangerously unprepared for a GPS attack

    The Hill: America is dangerously unprepared for a GPS attack

    We just finished the year that marked the 30th anniversary of America’s Global Positioning System (GPS) reaching full operational capacity. What began as a military tool to enable U.S. military forces to navigate more precisely and to support the use of precision strike weapons anywhere in the world has become the invisible infrastructure that powers nearly every aspect of civilian life. So much of our everyday lives, from smartphones and ATMs to aviation, shipping and Wall Street, run on precise timing and location information.

    However, that infrastructure is now under duress. Our adversaries are waging a sophisticated war on GPS signals, and the fallout is both significant and frightening. Reports of navigational issues across the Baltic and the Middle East have become a daily occurrence due to conflicts in the region. The impacts have extended into civilian life, impacting air, land and sea.

    It’s a miracle the regions have avoided a major aviation disaster, given that navigational warfare and space have become new domains of nation-state confrontation. Russia is spoofing and jamming signals across Eastern Europe. Russia and China are also shadowing military and civilian satellites, performing dangerous dogfighting maneuvers in orbit.

    Jamming and spoofing were once rare. Now, they are battle-tested tools in the electronic warfare arsenal, and the U.S. is not immune to their effects. What’s happening in these regions today could happen over Chicago or Atlanta tomorrow.  

    Similar interference has been detected near major U.S. airports, including Dallas and Denver, impacting nearly 350 flights. Nation-states were not responsible for these incidents, but they prove how vulnerable GPS is to disruption.

    This isn’t a Hollywood thriller. A coordinated attack on GPS would ripple across aviation, finance, emergency response, and daily life within minutes, not days. We’ve already seen how quickly systems collapse when digital links are severed.

    In 2022, a volcanic eruption in Tonga severed the country’s only undersea cable and blocked satellite signals, plunging the island into an instant blackout. Commerce broke down, and government emergency coordination collapsed. ATMs couldn’t dispense cash because banks couldn’t confirm account balances. Cargo planes couldn’t file manifests, and supply chains froze. Farms and fisheries couldn’t complete online forms, so produce rotted. Pharmacies couldn’t fill prescriptions because their supply systems were offline. The effects were immediate and took months to normalize.

    If GPS goes down, whether because of jamming, spoofing, a cyberattack or a natural disaster America is dangerously unprepared. Our widespread reliance on a vulnerable technology should be a wake-up call. A single sustained outage could cost the U.S. economy an estimated $1.6 billion per day.

    When I served as commander of U.S. Cyber Command, our team was responsible for ensuring the networks underpinning our military missions were fully operational and secure, and as the director of the National Security Agency, the team was focused on generating deep knowledge of threats to the U.S. and allied operations across land, sea, air, space and cyberspace. In both roles, it became very clear that we needed to protect our positioning, navigation and timing infrastructure, and that one of the keys to doing so was to create layered resilience.

    Solving a problem of this magnitude is a massive challenge. But we don’t need to start from scratch. By leveraging existing infrastructure in space and on the ground, we can accelerate deployment, reduce cost and avoid duplication. Speed and scale are essential. It’s not a question of whether the U.S. experiences a major GPS disruption, but when.

    Fortunately, the technology already exists. American companies are developing methods to provide positioning, navigation and timing backup via terrestrial 5G networks, offering timing and location signals that are independent of satellites. These solutions are scalable, cost-effective and designed to integrate directly into existing telecom infrastructure such as cell towers. If commercial providers are already exploring complementary backup technologies, why are we still lagging behind our adversaries?

    The real barrier isn’t technology — it’s policy. Moving the process forward to make these technical capabilities a reality is the challenge. Getting government bureaucracies to act with urgency is never easy, but the administration and Congress now recognize the stakes.

    The Federal Communications Commission has launched an inquiry into strengthening national positioning, navigation and timing infrastructure, including exploring ground-based alternatives such as 5G-powered systems. Now it’s time to follow through and move from planning to execution.

    The threats are real; the technology is ready; and the cost of inaction grows by the day. Replacing GPS is not a realistic near-term solution, either in terms of cost or the time frame required to do so. Our focus should be on building a layered, resilient system that provides users with multiple options to react to loss or degradation of our current positioning, navigation and timing structure. One layer of that system should be a ground-based component that takes advantage of the existing infrastructure already in place, saving us significant time and money in creating a solution to this critical problem.  

    This piece originally appeared on The Hill.