“The new LightSquared business plan and the new FCC rules significantly expand the terrestrial transmission increasing the potential for interference to GPS receivers,” the U.S. departments of Defense and Transportation (DOD and DOT) wrote to the Federal Communications Commission in 2011 after the FCC granted the company permission to offer broadband via its satellite and base station networks to a wide variety of mobile broadband partners. The move — heralded by supporters as hastening the advent of 4G services across the country, especially in underserved communities — sent shockwaves across the GNSS/PNT community, which opposed the plan forcefully for the threat it posed to GPS.
Reborn in December 2015 as Ligado Networks, the company obtained the FCC’s unanimous approval in April 2020 for the use of spectrum near the L-bands used by GPS for its 5G network. It is scheduled to launch its first deployment at the end of September.
Nearly all the federal government, including DOD and DOT, as well as most manufacturers of GNSS receivers, are very strongly opposed. On September 9, the National Academies of Science, Engineering and Medicine’s Committee to Review FCC Order 20-48 will release its independent evaluation of the issue, as mandated by the 2021 National Defense Authorization Act.
The study, begun in May 2021, considered three issues:
1. Which of two prevailing proposed approaches for evaluating harmful interference is most effective to mitigate the risk of harm.
2. The potential for harmful interference from Ligado to mobile satellite services — such as Iridium.
3. The feasibility and practicality of the remedies proposed by the FCC.
I am very pleased to announce that Prof. Penina “Penny” Axelrad has joined GPS World’s Editorial Advisory Board.
Penny is a University of Colorado (CU) Distinguished Professor in the Ann and HJ Smead Department of Aerospace Engineering Sciences. She received her B.S. and M.S. degrees in Aeronautical and Astronautical Engineering from MIT and her Ph.D. in Aeronautics and Astronautics from Stanford University. She has been a member of the faculty at CU since 1992, serving as primary advisor for 25 Ph.D. graduates and many M.S. and undergraduate research students.
Penny has been active in research on GPS and PNT technology and applications for aircraft, spacecraft and remote sensing, as well as estimation of satellite orbits and attitude, since 1985, co-authoring more than 60 journal papers and 130 conference papers. She has served as principal investigator or co-investigator on grants and contracts totaling $17 million. She is a Fellow of the Institute of Navigation and the American Institute of Aeronautics and Astronautics, and a member of the National Academy of Engineering. Since 2013 she has served as a member of the National Space-Based Positioning, Navigation and Timing (PNT) Advisory Board.
I overlapped with Penny at MIT in the mid-1980s. Now, nearly 40 years later, I look forward to her contributions to this magazine.
A roundup of recent products in the GNSS and inertial positioning industry from the September 2022 issue of GPS World magazine.
OEM
Receiver Upgrade
OSNMA anti-spoofing tech now on PolaRx5 GNSS reference receivers
Photo: Septentrio
Open Service Navigation Message Authentication (OSNMA) is now available on the high-end PolaRx5 reference receiver series. OSNMA offers end-to-end authentication on Galileo’s civilian signals, protecting receivers from GNSS spoofing attacks. OSNMA adds another layer of security to the receivers’ existing AIM+ anti-jamming and anti-spoofing technology. The PolaRx5 product range also now supports RINEX format versions 3.05 and 4.0.
The MAGNA-F and MAGNA-I GPS anti-jam antennas provide simultaneous L1/L2 protection and can protect commercial and military GPS receivers on aircraft. The MAGNA products were developed with sponsorship by the U.S. Navy and further improved by the U.S. Army to support GPS protection requirements for air, sea and ground platforms, such as fixed-wing/rotary aircraft, ships, UAVs and tactical vehicles. The MAGNA-F uses a 3.5-inch-diameter controlled reception pattern antenna (CRPA) compatible with existing fixed radiation pattern antenna (FRPA) footprints. The MAGNA-I (NavGuard 730) is a high-performance yet small GPS anti-jam integrated solution with a 4.5-inch diameter FRPA-compatible footprint.
Centimeter-level GNSS for mass-market applications
Photo: ArduSimple
The SimpleRTK2B single-board computer (SBC) is built around up to three u-blox ZED-F9P high-precision GNSS receivers. It simplifies development of centimeter-level positioning solutions supporting real-time kinematics (RTK), making the technology accessible to broader audiences. The SimpleRTK2B-SBC was developed to make RTK technology as close to plug-and-play as possible. In addition to working as a stand-alone solution, customers can program their own applications with the company’s microPython API. The SimpleRTK2B-SBC delivers mechanical integration with centimeter position on three axes (heading, pitch and roll), outputting on NMEA, RTCM, RS232 and CANBus interfaces via Ethernet, Bluetooth, Wi-Fi and 2G/3G/4G communication. It offers configurable input/output and an inertial measurement unit.
For assured positioning, navigation and timing (PNT)
Photo: ADVA
The OSA 3300-HP is a high-performance optical cesium clock with a 10-year lifetime compared to the five-year lifetimes of high-performance magnetic clocks. It provides the resilience required for PNT assurance in critical infrastructure and empowers service providers to deliver differentiated service-level-agreement timing offerings with integrated GNSS backup. The OSA 3300-HP has embedded Ethernet- and IP-based management as well as a user-friendly touchscreen graphical user interface.
With M-Code capabilities and upgrade paths for other GNSS systems
Photo: Collins Aerospace
NavHub-200M is a vehicle navigation system for the international market with military code (M-code) receiver capabilities. NavHub-200M provides assured positioning, navigation and timing (APNT) while improving overall resistance to threats to GPS, such as jamming and spoofing. Its message formats and signal modulation techniques ensure faster and more accurate performance for ground vehicles on the connected battlespace, while advanced security features prevent unauthorized access or exploitation. NavHub-200M also includes the open interface standards and sensor-fusion capabilities required for a GNSS upgrade path, such as that for Europe’s Galileo constellation, as well as the ability to interface with key vehicle sensors such as the inertial measurement unit (IMU) and odometer.
The Trimble TDC650 handheld is built for data collection, inspection and asset management activities. The rugged solution provides scalable high-accuracy GNSS positioning for professional field workflows, including apps such as Esri ArcGIS Field Maps and Trimble TerraFlex software. The TDC650 is scalable, allowing customers to choose their desired accuracy down to the centimeter level.
Powerful solution for manned and unmanned aircraft
Photo: YellowScan
The Voyager long-range lidar scanner has a wide field of view, with all points collected oriented toward the ground so there is no loss of points. In all, 1.5 million points per second will be usable. Voyager combines a Riegl VUX-120 laser scanner with a Trimble Applanix AP+ 50 AIR or Applanix AP+ 30 AIR GNSS-inertial board, providing a precision of 0.5 cm and an accuracy of 1 cm. Voyager’s detection and processing of up to 15 target echoes per laser pulse allows for excellent vegetation penetration. It has an extremely fast data-acquisition rate of up to 1,800 kHz, suitable for projects requiring the highest point density. The laser scanner’s specifications can be customized and can be combined with YellowScan’s software solutions.
Extends 3D Tiles Next workflow into Esri ArcGIS Pro
Photo: ArcGIS
The 3D Environments Add-In application for Esri ArcGIS Pro allows ArcGIS users to rapidly transform 3D Tiles Next data formats, such as One World Terrain, into ArcGIS Pro projects to create 3D scenes from 2D vector data and 3D models. The add-in leverages Presagis’ building templates and texture libraries that analysts use to create enhanced 3D visualizations of GIS environments, helping increase collaboration across the enterprise. The 3D Environments Add-In contains tools to create, transform and extract a wide variety of 3D formats to provide seamless interoperability between ArcGIS Pro and modeling and simulation applications. It is available on the Esri ArcGIS Marketplace.
Energy performance data helps tackle climate change
Photo: XMAP
Municipal geographic information system XMAP can now incorporate the energy-performance ratings of individual properties to help local authorities tackle climate change, improve housing standards, and ensure landlords comply with legislation. The Energy Performance Certificate (EPC) data layer uses a rating system similar to the one used on new appliances, ranging from A (very efficient) to G (inefficient). It allows tenants and house buyers to make informed decisions. In addition to a color-coded visualization of current ratings, the XMAP EPC layer contains enhanced analysis including generalized ratings and the potential for improvement. Bath and North East Somerset Council, UK (pictured), has embraced this resource and is looking at how the data can be used to raise housing standards.
The Elios 3 is a collision-tolerant drone equipped with a lidar sensor for indoor 3D mapping. The drone is powered by a new SLAM engine called FlyAware that lets it create 3D models as it flies. It also hosts a new version of Flyability’s software for inspectors, Inspector 4.0. The Elios 3 comes with an Ouster OS0-32 lidar sensor, allowing inspectors to collect data for the creation of survey-grade 3D models using Connect software from Flyability’s partner GeoSLAM. Protected by a cage, the Elios 3 has advanced collision-tolerance features that allow inspectors to fly it inside dangerous confined spaces such as boilers, pressure vessels and mines.
The R60 is a powerful handheld with an ergonomic design. It runs on Android 12 OS, providing a suitable workhorse for surveying professionals in the field. Survey Master field software works seamlessly on the R60, which features a Qualcomm 8-core processor for massive data processing. Its 64-GB memory allows ample data storage and enables the opening of CAD drawings in seconds. Other features include a QWERTY keyboard, a 5.5-inch sunlight-readable high-resolution screen, an IP67 rating (dustproof and waterproof), and a 9,000 mA Li-ion battery for more than 30 hours of continuous functioning.
The Mobile Centimeter (MobileCM) Space Weather Station is a ready-to-use GNSS device that will act as a real-time kinematic (RTK) base station and collect space weather data. The device is pre-configured to securely connect with the Global Earth Observation Decentralized Network (GEODNET) using a home Wi-Fi network. The full four-constellation GNSS base station has built-in NTRIP server functionality and is packaged with a survey-grade triple-band roof antenna and required cables.
The SAgro10 GNSS guidance system is an entry-level guidance system for precision agriculture, providing users with higher navigation precision and higher productivity, which can be upgraded to an automatic steering system. Embedded with a high-precision GNSS module, the SAgro10 system tracks all four global constellations. For users with network coverage or a UHF base station, the system provides centimeter-level accuracy navigation in real-time kinematic mode. In the absence of base stations, the SAgro10 system provides sub-meter navigation accuracy in single-point smoothing mode. Compatible with most agricultural tractors, its components can be installed within 15 minutes. The 10-inch sunlight-readable touchscreen has a clear and simple graphic interface.
iDig 3D Connect is a solar-powered excavator guidance system with a GNSS receiver that can be removed and used as a rover, rather than permanently installed on the machine. 3D excavator guidance has seldom been used for small projects such as house foundations because of the need for a surveyor to stake out points and map a site. The removable receiver enables contractors to complete these tasks. The software provided creates a GNSS-generated site map, enabling precision digging relative to the area and making the process quicker, simpler and more eco-friendly than with 2D.
The Cloud Locator service takes data from LoRa Edge-enabled devices and uses Semtech’s LoRa Cloud Geolocation and Modem services for asset tracking both indoors and outdoors. It features built-in serverless technology and enables testing of ultra-low-power asset tracking on either a private or public LoRaWAN network. It is designed to work with trackers using Semtech’s LoRa Edge LR-series chips. The LR-series chips combine Wi-Fi and GNSS to obtain the latitude and longitude of devices in any indoor or outdoor location. Once configured on the service, together with Semtech’s LoRa wireless radio frequency technology for transmission to the cloud, customers can view the tracker location on a map in less than 15 minutes.
The Edge 1040 bike computer features solar charging and multi-band GNSS technology. Its multi-band GNSS receiver (GPS, GLONASS and Galileo) provides accurate positioning in challenging ride environments, such as dense urban areas or under deep tree cover. Advanced navigational tools help cyclists stay on track, such as turn-by-turn navigation and alerts that notify riders of sharp curves ahead. Route guidance and off-course notifications can be paused for exploring and turned back on for return to the original route. When using the Trailforks app, Forksight mode automatically displays upcoming forks in the route and where a rider is within a trail network.
Skydel 22.5 is a significant software upgrade to the Skydel simulation product line. It features advanced hardware-in-the-loop (HIL) testing solutions providing very low to zero effective latency. Enhanced visualization tools can monitor internal latency through real-time curves showing when the data is generated and sent to the RF signal. Users can also review the transmission of HIL packets for optimizing the entire network’s latency, checking its stability (jitter), and that data is available and used at the right time in Skydel. HIL testing is an essential step in the verification process of the model-based design approach because it involves all the hardware and software that will be used operationally.
The Time-Loader is designed for defense and mission-critical applications, for deployment in environments where GNSS signals are denied or disrupted. It supports any ground, naval or airborne system that needs real time of day (TOD) and 1PPS external synchronization aligned to the UTC or GNSS. It generates a GPS L1 C/A code RF output as if the signal were coming from a live-sky GPS antenna. It provides full-constellation GPS output and is compatible with external GNSS receivers. Its GPS-disciplined oscillator (GPSDO) is the Microsemi MAC-SA53/55, which provides excellent UTC accuracy with outstanding hold-over rubidium clock performance. A self-contained, miniature GPS simulator provides real-time extremely accurate signals. The 18-channel full-constellation simulator stores location/time/date data in internal memory and stores complex vector data to simulate dynamic scenarios. The simulator also can be used to transcode NMEA or SCPI position/ velocity/time (PVT) data into GPS RF signals.
BAE Systems has received a $13 million contract for advanced GPS technology to protect U.S. F-15E aircraft from GPS signal jamming and spoofing. The company’s Digital GPS Anti-jam Receiver (DIGAR) will ensure the reliability of military GPS systems for aircraft operating in challenging signal environments.
DIGAR uses advanced antenna electronics, high-performance signal-processing and digital beamforming — a capability that combines 16 steered beams — for better GPS signal reception and superior jamming immunity. These capabilities are critical for high-speed aircraft as they maneuver through the battlespace.
The F-15 Eagle is the second U.S. Air Force fighter platform to receive DIGAR GPS upgrades, following the F-16 Fighting Falcon. DIGAR also provides advanced GPS capabilities for intelligence, surveillance and reconnaissance aircraft as well as multiple unmanned aerial vehicles.
Two U.S. Marine Attack Squadron 211 F-35B Lightning IIs and two U.S. Air Force F-15 Eagles assigned to the 67th Fighter Squadron, fly over United Kingdom aircraft carrier HMS Queen Elizabeth over the west Indo-Pacific region in August 2021. (Photo: USAF/Staff Sgt. Kyle Johnson)
“Modern airborne missions require accurate positioning and navigation data, and GPS systems must be able to withstand adversaries’ best disruption efforts,” said Greg Wild, Navigation and Sensor Systems product line director at BAE Systems. “Our DIGAR antenna electronics are trusted to protect these platforms in contested environments.”
BAE Systems’ family of military GPS products offer size, weight and power characteristics suitable for a variety of applications, including handheld electronics, vehicles, unmanned aerial vehicles, aircraft and precision-guided munitions. In addition to GPS anti-jam products, the company is delivering advanced GPS products compatible with the next-generation M-code satellite signal, and is developing the next generation of receivers to ensure dependable GPS for warfighters across land, air and sea domains.
BAE Systems work on military GPS technology takes place in Cedar Rapids, where the company is investing more than $100 million to build a 278,000-square-foot, state-of-the-art research and manufacturing center.
An F-15 Eagle with the 159th Fighter Wing, Louisiana. (Photo: USAF/Tiffany A. Emery)
Partnership will test future eVTOL flight routes and concept of operations in the Kansai region
Photo: Airbus
Airbus is partnering with Japanese helicopter operator Hiratagakuen to develop advanced air mobility services in the Kansai region and beyond. Through this agreement, the companies will tackle crucial aspects required to launch a commercial transportation service with CityAirbus NextGen.
As a first step, the partners’ joint project to organize a simulation of ideal routes, concepts of operations, and necessary equipment for safe electric vertical takeoff and landing vehicle (eVTOL) flights in the Kansai region. Kansai was selected by the Osaka prefecture for the project. A demonstration flight is scheduled for later this year.
With the aim to implement air mobility services beyond urban environments, the joint work of Airbus and Hiratagakuen will support the development of advanced air mobility solutions with CityAirbus NextGen for use cases ranging from air medical services to commercial air transport and ecotourism in a variety of operational contexts.
Airbus and Hiratagakuen will use an H135 helicopter to test advanced navigation and communication technologies for safe operations of eVTOLs in urban environments, while simulating CityAirbus NextGen’s flight configuration.
Hiratagakuen is a Kansai-based helicopter operator that specializes in helicopter emergency medical services (HEMS), transportation of personnel, flight training and maintenance. The company’s fleet includes 14 H135 and two H145 helicopters.
In September 2021, Airbus unveiled its eVTOL prototype CityAirbus NextGen to explore advanced air mobility technologies. The company plans to construct a dedicated center to test the aircraft’s systems in the lead-up to its maiden flight. Airbus is also working closely with industrial and institutional partners to lead the development of urban air mobility ecosystems, including ITA Airways in Italy and launch of the Air Mobility Initiative in Germany.
SABIC, a global leader in the chemical industry, has introduced two new LNP Thermocomp compounds that offer the potential to improve signal gain performance compared to ceramics in second-generation automotive GNSS antennas.
The new compounds, LNP Thermocomp ZKC0CXXD and LNP Thermocomp ZKC0DXXD, help enable the design and molding of antenna substrates with more complex pattern markings that add effective surface area, a critical factor in enhancing signal capture.
For customers that use ceramics, switching to the LNP Thermocomp compounds can help lower system costs by avoiding secondary operations, as well as improving antenna performance. Designers and engineers who find current materials inadequate for developing novel, high-resolution GNSS antennas can help address new requirements with the SABIC products, the company said.
“As GNSS antenna technology advances to its second generation with higher resolution, SABIC continues to enhance the scope and capabilities of our LNP specialty compounds portfolio to meet new performance requirements,” said Joshua Chiaw, director of business management, LNP, SABIC. “Our new LNP Thermocomp compounds can help antenna manufacturers achieve superior signal gain compared to ceramic substrates. They also provide flexibility to produce smaller parts with the same performance as ceramic, or equal-size parts with better performance. This remarkable combination of improved signal capture and design freedom, plus system cost advantages, can help propel innovation in GNSS technology — a keystone of occupant safety today and autonomous driving in the future.”
The LNP Thermocomp compounds, which offer a high dielectric constant (Dk) for miniaturization and a low dissipation factor (Df) to facilitate signal acquisition, can be tailored to meet the electrical requirements of individual applications. They feature electroplating capability, good thermal resistance for reliability, and the design freedom and production efficiency of thermoplastics. Both are well-suited for shark fin-style and new conformal antenna designs.
Vodafone and Topcon Positioning Group are developing a European precise positioning system, Vodafone GNSS Corrections, that will locate Internet of Things (IoT) devices, machinery and vehicles with a greater degree of accuracy than using individual GNSS.
Vehicles, scooters and robotic lawn mowers can be securely monitored in real time to within a few centimeters when connected to Vodafone’s global IoT network.
Vodafone GNSS Corrections will use technology from Topcon, which corrects inaccuracies from navigation satellite signals. Location accuracy is improved from a few meters to centimeters using Topcon’s dense European network of thousands of GNSS reference stations, especially when vehicles and devices are fitted with suitable antennas and receiver equipment.
Vodafone will offer a singular module configuration that can extend across national borders.
Vodafone is inviting select customers to join pilot customer trials in Germany, Spain and the UK, which will begin this month. The companies aim to test the service using a wide variety of devices connected to Vodafone’s global IoT network — one of the largest with more than 150 million connections — and its pan-European network covering 12 countries.
Pinpoint accuracy is critical to the mass adoption of vehicle-to-anything (V2X) technology used for driverless vehicles, autonomous machinery and robots. For example, e-bike riders could use Vodafone GNSS Corrections to provide details of their exact location and then alert other road users of their presence.
Vodafone GNSS Corrections also supports Vodafone’s efforts to improve V2X location accuracy, especially when sharing trusted data to help prevent unnecessary accidents and fatalities on Europe’s roads. As such, Vodafone is offering precise positioning as a complement to Vodafone’s new Safer Transport for Europe Platform (STEP) which allows entities to communicate with each other where no line of sight exists. Unveiled in March 2022, STEP has been successfully tested in Germany and the UK and will be made available via Vodafone Automotive and third-party apps later this year.
Technology changes the rules of the game, and surveying may be more in its crosshairs than the profession will admit
Maps have existed for centuries. The lines on maps indicating the boundaries of political and administrative units — cities, counties, states, and countries — are graphic representations of the limits of those entities. These lines don’t, however, typically exist in real life. There isn’t a large line between the United States and Canada stretching from the Pacific Ocean, through the Great Lakes, and onto the Atlantic Ocean.
The same goes for latitude and longitude lines on maps and globes. The public generally accepts the various delineations on maps as being somewhat accurate with an unwritten level of trust in those who have produced these maps.
Definition
trust: assured reliance on the character, ability, strength, or truth of someone or something.
Here are the guidelines surveyors use for determining surveys.
lines physically verified in the field and proven from evidence
monuments and/or boundaries set and called for within legal descriptions
natural monuments
artificial monuments
adjoiners (to determine junior/senior rights)
courses
bearings, then distances (metes and bounds states)
distances, then bearings (public land survey states)
recitation of area
controlling description
evidentiary description
coordinates: local and/or geodetic
Surveyors rely on physical monuments, title documents and evidence of occupation to assist with the establishment of not just major dividing lines, but all lines of property, public or private. Finding, setting and honoring physical monuments has been a significant character trait of the surveyor for as long as maps have existed.
Monuments are placed to determine the endpoints of these lines as depicted on maps or plats, but what happens when technology introduces new ways to re-establish these lines? What will happen to our monuments when technology — more specifically those who utilize them — deems them obsolete?
The guidelines above are known as “priority of calls” or “rules of construction” by the surveying community. These items have provided the instructions for surveyors to follow in retracement of lines for many years. However, like nearly everything else in our modern world, technology has a hand in modernizing even this time-honored “surveyor’s code of retracement.”
Who would have guessed that the rotary phone dial would give way to touch-tone buttons, that the system would jump from landlines to cellular and satellite signals to remote handsets, then progress to receivers evolving away from physical buttons to touchscreens?
Technology changes the rules of the game, and surveying may be more in its crosshairs than the profession will admit.
Here come the numbers
Note that the last entry in the above guidelines for survey retracement is “coordinates.” In accordance with most accepted lists, coordinates can be local or geodetic. These coordinate values are generated by surveyors, geodesists and public agencies; they can be found on plats, and in records and websites kept by government agencies.
Now that we are more than two decades into the 21st century, it would be safe to say that most of the surveying profession uses an established geodetic coordinate system. The use of GNSS receivers is widely accepted as normal practice by many surveyors because these systems are much more user friendly than in years past. Additional constellations have added to the availability and accuracy of GNSS positional values, so utilizing state plane coordinates has become the norm.
We are now surrounded by something that has an incredible impact on our profession and the world around us. We are placing trust in a georeferenced coordinate system that cannot be identified by any of our senses, like we can with a physical monument.
A coordinate cannot be seen, touched, tasted, heard or smelled.
We are placing our full trust in a reliable position on Earth as determined by our GNSS receiver working within a published coordinate system. Because of these advancements in technology, a new generation of geospatialists is insisting we should revise the way we survey, because technology provides much higher precision and accuracy.
Just like lines on a map or plat, coordinates only exist as a calculation of a position on the face of Earth. So why is there animosity in trusting coordinates over the more traditional items on the list of retracement guidelines? It may have to do with the fact that the ground we are surveying is not in the same place it was a short time ago. Depending on where you live, it may have moved more than you think. For more information on the shifting ground we live on, let us dig into some research about our continents.
From about 300-200 million years ago (late Paleozoic Era until the very late Triassic), the continent we now know as North America was continuous with Africa, South America and Europe. They all existed as a single continent called Pangea. Pangea first began to be torn apart when a three-pronged fissure grew between Africa, South America and North America. Rifting began as magma welled up through the weakness in the crust, creating a volcanic rift zone. Volcanic eruptions spewed ash and volcanic debris across the landscape as these severed continent-sized fragments of Pangea diverged. The gash between the spreading continents gradually grew to form a new ocean basin, the Atlantic. The rift zone known as the mid-Atlantic ridge continued to provide the raw volcanic materials for the expanding ocean basin.
Meanwhile, North America was slowly pushed westward away from the rift zone. The thick continental crust that made up the new east coast collapsed into a series of down-dropped fault blocks that roughly parallel today’s coastline. At first, the hot, faulted edge of the continent was high and buoyant relative to the new ocean basin. As the edge of North America moved away from the hot rift zone, it began to cool and subside beneath the new Atlantic Ocean. This once-active divergent plate boundary became the passive, trailing edge of westward moving North America. In plate tectonic terms, the Atlantic Plain is known as a classic example of a passive continental margin.
Today, the Mesozoic and Cenozoic sedimentary rock layers that lie beneath much of the coastal plain and fringing continental shelf remain nearly horizontal.
Image: USGS
In geologic terms, a plate is a large, rigid slab of solid rock. The word tectonics comes from the Greek root “to build.” Putting these two words together, we get the term plate tectonics, which refers to how the Earth’s surface is built of plates.
The theory of plate tectonics states that the Earth’s outermost layer is fragmented into a dozen or more large and small plates that are moving relative to one another as they ride atop hotter, more mobile material. Before the advent of plate tectonics, however, some people already believed that the present-day continents were the fragmented pieces of pre-existing larger landmasses (“supercontinents”).
The diagrams below show the break-up of the supercontinent Pangaea (meaning “all lands” in Greek), which figured prominently in the theory of continental drift — the forerunner to the theory of plate tectonics.
Image: USGS
Continental drift, plate tectonics and prime meridians
Historians and other scientists have theorized about Pangea for centuries. Common soil types, fossils, and other evidence found on different continents help to solidify the concept of Pangea. Items discovered on the west coast of Africa have many similarities with those found on eastern South America. The physical evidence is quite convincing that an earlier supercontinent existed millions of years ago.
Now, let’s apply a fixed measurement system with lines upon Earth that defines latitude and longitude. In the past, geodesists, geographers and mathematicians established various “prime meridians” around the world to serve as a basis for maps. Locations and cities used included Amsterdam, Antwerp, the Bering Strait, Bern, Brussels, Copenhagen, Florence, Giza, Jerusalem, Kyoto, Lisbon, Madrid, Naples, Oslo, Paris, Philadelphia, Pisa, Rio de Janeiro, Rome, Stockholm, Warsaw and Washington, D.C. (in four different places!), just to name a few.
Thankfully, scientists gathered in the 19th century to agree upon a singular “initial meridian” that would pass through Greenwich, England, and was based upon several centuries of astronomical observations at the nearby Royal Observatory.
For approximately 100 years, mapmakers (and geodesists) used the new Prime Meridian at Greenwich as the beginning baseline for longitude determination around the world. After all, it was based upon years of astronomical observations and solved the age-old problem of where longitude starts. (Latitude was a much easier calculation for astronomers and geodesists, but that story is for another day.)
The late 20th century and the fourth industrial revolution
Technology, once again, provides us with conflicting results. While most technological advancements are game-changing improvements to mankind, they also tend to shake up information and standards that have existed for many generations. Like the previously discussed advancements in telephones, technology makes us change the way we look at things and how we go about our lives.
Mapping has become a central part of our everyday lives. Georeferenced positions for literally everything is now a standard characteristic of many functions within our environment, especially in our surveying world. Most of these improvements are due to GPS, which was originally developed for the U.S. military to guide and assist with positional location of our defense systems in relation to our enemies. We use this same precise technology to establish positional locations for boundary points, infrastructure and topographic information.
Image: Tim Burch
We have also used GPS to learn much about our tectonic plates and varying movement of the continents.The first thing we learned is that the Prime Meridian established in 1884 does not fall in the same place as our 0° latitude designation as determined by GPS/GNSS calculations.
This finding, however, is not the telling item within our adaptation of GPS data; it came when various agencies established the continuously operating reference system (CORS), composed of static GPS base stations. CORS stations, while used to help establish new survey positions in relation to a known reference location, also measure a continuous drift of latitude and longitude positions over time.
The National Geodetic Survey (NGS) is in the process of finalizing a new reference framework for establishing coordinate values that utilize time as a core component. Future implementation of the new National Spatial Reference System (NSRS) will require the additional attribute of time within the metadata of any new values.
So how does this affect surveying and the monuments we surveyors hold on such a high pedestal? The answer varies depending on who one asks. Most surveyors will continue to hold the “priority of calls” as listed above. Several practitioners, however, want to move coordinates higher up the list because of technology, and the ability to retrace a published point because of the increase in technology and the higher accuracy and precision of today’s GNSS.
This is possible if the user of the technology follows the procedures as established by NGS with metadata and accurate timing, but there are still several variables in the setting and retracing methodologies. When was the last time the equipment was calibrated? Was adequate research performed to minimize environmental errors? Was there any interference due to solar storms or multipath? There are many potential issues a surveyor can face, but few are checking all the boxes when performing highly accurate and precise positional measurements.
Technology has brought surveying into the 21st century with GPS/GNSS and ever-increasing accuracy and precision. It should also be the profession’s goal that the technology does not override what the general public can see. They can see monuments, fence lines, buildings and other improvements, but they cannot see coordinates, which remain invisible to the naked eye. Technology may change that in the future, too, but until that time, we must rely on what we can see.
Project GENIE (GNSS Excluded Navigation Intelligent Enhancement) will mature and advance non-GNSS solutions as part of a long-term objective to enable assured location and navigation in commercial aerospace, helping to unlock the benefits and value of autonomy in civil aviation. The support from NATEP will enable the consortium to take a significant step toward navigation in GNSS-spoofed or -denied environments, the companies said.
“Tomorrow, as we look towards single-pilot operation and future autonomous aircraft, there will not be a pilot or air traffic controller available to mitigate these risks,” stated the companies in a press release. “GENIE has been developed to step into this role. It will be able to identify when a GPS signal has been compromised and, using a combination of techniques, provide a location position as accurate as GPS.”
“The need to provide assured, resilient navigation is a critical enabler for autonomy in the aerospace environment,” said Charles Smith, CCO at Archangel Imaging. “GENIE is a core element of this, and we are very excited to be working with NATEP to help push this technology forward. We see significant commercial exploitation opportunities as a result of this project in the UAV and broader aviation markets and are thrilled to be a part of this round of NATEP funding and support.”
Trimble is committing to reduce greenhouse gas emissions in line with the ambitious goals of the Paris Agreement and a net-zero future to keep global temperature increase to 1.5° C.
“Taking decisive climate action is essential to protect our planet and communities for future generations,” said Rob Painter, president and CEO, Trimble. “It also demonstrates Trimble’s commitment to our purpose — to transform the way the world works as well as transform the way ‘we’ work.”
“For decades, Trimble solutions have contributed to reducing greenhouse gas emissions and combating climate change,” Painter said. “The nature of Trimble’s technologies, which connect the physical and digital worlds, provides efficiencies and promotes sustainability in our end markets such as construction, agriculture, forestry, utilities and transportation. Our leadership team is committed to further reducing our carbon footprint as well as continuing to develop solutions that enable our customers to reduce their climate impacts — it is an important lever in our Connect and Scale strategy. Trimble is dedicated to do its part to help protect and build a better world.”
Trimble’s science-based targets accelerate decarbonization across its value chain, and include the following commitments:
reduce absolute scope 1 and 2 greenhouse gas emissions by 50 percent by 2030 from a 2019 base year
achieve 100 percent annual sourcing of renewable electricity by 2025
reduce absolute scope 3 greenhouse gas emissions from fuel and energy-related activities, business travel and upstream transportation and distribution by 50 percent by 2030 from a 2019 base year
commit to partner with 70 percent of its suppliers by emissions covering purchased goods and services and capital goods to set science-based targets by 2026.
“Setting ambitious yet achievable climate targets is part of our commitment to reducing Trimble’s carbon footprint,” said Leah Lambertson, senior vice president and head of Sustainability, Trimble. “Embedding our climate action goals into Trimble’s operational choices will help ensure that our decision making and growth plans are consistent with our low-carbon vision. Today’s commitments are important steps in our journey to delivering growth in a responsible and sustainable way to achieve a net-zero future.”
Trimble’s 2021 Sustainability Report
Trimble also announced the release of its 2021 Sustainability Report. Built around the company’s mission of transforming the way the world works, the report describes how Trimble is helping to create a better future for the planet and the communities it serves.
The report summarizes its initiatives and performance across environmental, social and governance (ESG) topics, highlighting the company’s sustainability approach; end-user industry solutions; community philanthropy through its Trimble Foundation Fund; employee engagement and development as well as diversity, equity and inclusion (DEI) initiatives; and governance.
By Nino De Falcis, Senior Director of Business Development, ADVA
Today’s critical network infrastructure is heavily reliant on positioning, navigation and timing (PNT) services. Power grids, financial markets, transportation, data centers, communications — all have become more complex and interconnected, while the threats to the PNT on which they depend have grown in frequency and sophistication. PNT systems are so vulnerable to the activities of cybercriminals that attacks may soon become global in scale and significance, with potential costs of billions of dollars.
Utilities are a key example of infrastructure at risk. In the past, power networks were passive systems with everything simple and centralized, and with energy flowing in one direction only as AC power was provided to consumers. However, the growth in renewables and distributed energy resources has spurred diversification of the market, and a new paradigm of bidirectional AD and DC energy production and distribution has emerged: the smart grid.
Timing Challenges
Today, many smaller producers are generating power from multiple sources. The power grid has become a decentralized system and the flow of energy is now bidirectional. Energy from solar panels (microgrids), for example, can be generated by private individuals and either stored or fed back into the grid. Electric vehicles (EVs) are also becoming more common, and like all other nodes across the smart grid, charging points require precise timestamping of the massive amount of data they generate to balance power demand and supply.
Precise timing is also key to rerouting power flows away from transmission outages, to locating power line faults, and for synchronizing distributed control and protection systems. Without highly accurate timing and synchronization, power grids are vulnerable to partial outages and even complete blackouts.
That is why accuracy requirements of data timestamping are tighter than ever. In fact, they are shifting from legacy Network Timing Protocol (NTP) timestamping, which has millisecond accuracy needs, to Precision Timing Protocol (PTP) timestamping, requiring sub-microsecond accuracy. The syncrophaser now demands accuracy better than 1 microsecond.
For fault location, we’re now at 100 nanoseconds. The micro-phasor measurement unit (PMU) is at less than 1 microsecond and substation LAN communication protocols have to be time-stamped at as low as 100 microseconds for GOOSE IEC 61850 and at 1 microsecond for IEC 61850 sample values. This is a big change from just five years ago when accuracy in all these categories was firmly in the millisecond range, and it’s a high bar that needs to be maintained by next-generation redundant systems, should GPS or ground-based timing become compromised.
Guidelines for making PNT infrastructure fully redundant are being pushed by governments across the world. In the United States, regulations are being driven by Executive Order 13905 with the Department of Homeland Security (DHS) providing a framework for how assured PNT (aPNT) should operate. It states that PNT infrastructure must perform three core functions: prevent, respond and recover. Infrastructure must have the ability to prevent atypical PNT errors and corruption of PNT sources. If prevention fails, networks must be able to respond to detected errors or anomalies and then recover from those errors.
The DHS framework outlines four resiliency levels. Level 1 has only one source providing PNT, while level 4 is a next-generation system leveraging multiple sources to derive and distribute PNT data. At Level 4, systems need to be self-survivable. This means they must function for long periods in the absence of a GPS timing source, or when ground-based timing sources have been otherwise compromised. There is even an IEEE P1952 resilient PNT standard in progress that will use this DHS framework.
Rising Threats
There are two categories of threat to PNT: external and internal. External threats include jamming (equipment that can block GPS is available off the shelf for as little as $20) and spoofing, which is the act of transmitting false GPS signals that trick receivers into calculating an erroneous position. Sophisticated cyberattacks can be in the form of either of these and spoofing (especially synchronous) is the most complex to detect.
The two main internal PNT threats come from attacks on NTP and PTP network timing as well as active GPS receivers connected to the network.
Legacy power grids have traditionally used NTP to distribute timing to substations, including IRIG, and this has already shown itself to be vulnerable to attack because it can be hacked by a process called NTP amplification.
Today, power grids are increasingly migrating to PTP because it provides the sub-microsecond accuracy needed for modern applications. PTP also has not yet been hacked, but that does not mean it soon will not be. If an attack did occur on ill-prepared critical infrastructure, the results could be catastrophic.
Secure Smart Grid Timing Components
There are two components in the smart grid: telecom connectivity to transport data, and grid protection that has different level generation grid control, transmission and management. On the telecom side, there is the edge telecom network and sometimes there are data centers. There are either core or edge data centers and these are also equipped with very good timing. A key concept in the data center is time as a service and GPS backup as a service when GPS goes down. The smart grid can also leverage this service as it gives even more robust protection and security against threats to PNT. See Diagram 1.
Diagram 1. A key concept in the data center is time as a service. (Image: ADVA)
A Resilient and Assured PNT Solution
As with other aspects of cybersecurity strategy, smart grids must employ a zero-trust framework of PNT sources. This approach never assumes that any one PNT source can be trusted. Instead, it uses a multi-source approach, verifying sources and comparing them to each other in real time to get the most accurate timing possible.
To prevent and mitigate interruptions to GPS, smart grid operators should deploy a resilient and assured PNT solution. This means it’s based around three integrated technologies: multi-layer detection, multi-source backup and multi-level fault-tolerant mitigation.
Multi-layer detection is performed through timing devices – either single or redundant – that have jamming and spoofing detection and monitoring capabilities. GNSS devices are also capable of comparing sources such as network PTP timing and they can be equipped with standalone, GNSS-backup clocks that leverage rubidium or cesium oscillators to obtain the most reliable timing information from other timing sources in the network.
Multi-source backup comes in the form of a cesium or rubidium oscillator that can provide extended holdover. Backup can be further bolstered with other sources such as eLORAN, NIST and LEO.
A neural network management system is an intelligent platform that ties everything together, from self-actionable recovery and assurance software to alerting users of issues in the network-wide timing infrastructure. It provides visibility and control of all aspects of prevention, mitigation and backup. The management system gives detailed operational data on the smart grid, showing the locations of the faults, the types of faults, and how PTP backup assurance is performing. Through capabilities powered by artificial intelligence and machine learning, the management and control system provides the end-to-end control, visibility, and trusted, assured PNT. It has all the intelligence to reveal threats and also take action against them, quickly recovering the network’s timing distribution capability, while keeping the network timing self-survivable. See Diagram 2.
Mitigating Cyberattacks with a Defense-in-Depth Approach
So, let us imagine there is a major attack on a smart grid. A jamming device has been used to block GPS reception on an edge grandmaster being used at a substation, while at the core of the network an ePRTC’s ability to receive GNSS signals has also been compromised. GPS is no longer viable as a source for timing in the smart grid.
The intelligent software monitoring and management system is the first line of defense, detecting and alerting operators to the two or more attacks on GPS: one at the core of the network and one at the substation. The network timing capability of the whole smart grid has been compromised.
Upstream from the substation, the core enhanced PRTC (ePRTC) has become an unreliable source of timing. However, it is equipped with a cesium clock that steps in to propagate trusted PNT backup into the substation and throughout the rest of the network. The cesium clock has no antenna, no RH signal, and is a stratum 1 clock that can propagate highly accurate timing (accurate to 1 microsecond over four months) throughout the network. It has now become the trusted source of timing until GPS can be re-established.
The most crucial element of PNT is timing. Without timing there is no positioning or navigation — it is the enabler of both — and so the distribution of accurate timing must be our top concern when we build systems.
For smart grids and all other critical infrastructure dependent on PNT to function, the cornerstone for secure and self-survivable timing networks is the concept of zero-trust. A multi-source approach to building timing networks will allow operators of critical infrastructure to leverage a combination of intelligent management software and timing devices equipped with adequate PTP holdover to respond to all threats to PNT.
To see a real-world example of this approach in action, check out the DOE DarkNet program.
“Seen & Heard” is a monthly feature of GPS World magazine, traveling the world to capture interesting and unusual news stories involving the GNSS/PNT industry.
3D mapping is helping forensic teams reconstruct fatal traffic accidents in Singapore, reports The Straits Times. In 2021, Singapore had 100 fatal road accidents. Experts use 3D replicas of the accident site and simulation models to recreate events leading to an accident and its aftermath. This helps forensic scientists determine whether the vehicles were speeding or flouting traffic rules. The National 3D Mapping Program of the Singapore Land Authority has mapped every road, lane and highway in Singapore with a 3D laser scanner and car-mounted cameras, and plans to update the maps regularly. Autonomous vehicles will also depend on the 3D point-cloud data.
Diagram: U.S. General Accountability Office
BeiDou Enables Hypersonic Flight
In simulation drills using BeiDou, Chinese space scientists flew a hypersonic flight from Jinan, China, to New York over the Arctic Ocean, reports EurAsian Times. BeiDou facilitated contact between the command center on Earth and the hypersonic vehicle as it dodged enemy air defenses. Researchers claim using BeiDou provided a time lag of less than a second. They also claim to have optimized signal transmitters and designed new satellite-jumping methods to overcome communication challenges. China and Russia are the only countries with operational hypersonic weapons — Russia has used its Kinzhal hypersonic missile in the Ukraine war.
Indonesia’s National Research and Innovation Agency (BRIN) and Dr. Soetomo University are cooperating on aerial photo mapping using an unmanned aerial vehicle and GNSS hardware. BRIN’s Ocky Karna Radjasa said he expects that the two parties will extend the opportunity to advance research and innovation as well as bolster the quality of education in Indonesia. The university’s Nur Saidah expects BRIN’s support will increase, stating, “We still have limitation in laboratory facilities, so we seek industry cooperation. Let us hope that, as a result of this cooperation, we can receive help.”
A new navigation system addresses shortcomings of GNSS using cosmic-ray muons. Muometric navigation enables positioning underground, indoors or underwater within a reference coordinate system defined by the 3D positions of multiple detectors, researcher Hiroyuki K. M. Tanaka explains in the June issue of Nature. Tanaka’s work shows the system offers a navigation quality almost equivalent to aboveground GPS-based handheld navigation by determining the distance between the reference frame and the receivers with a precision of 1 to 10 meters.
ComNav Technology Ltd. has released the N2 Palm RTK GNSS receiver. The release coincides with the company’s 10th anniversary. With its advanced technologies, the N2 is suitable for surveying, mapping and construction.
The N2 has a highly integrated main board and a three-in-one antenna, yet is extremely thin and portable, weighing about the same as a basketball (0.72 kg with battery) and measuring 48 mm, the thickness of AirPods.
Powered by ComNav’s SinoGNSS K8 high-precision module, the N2 can track 1,590 channels, including all existing and planned signals of GPS, BDS-2, BDS-3, GLONASS, Galileo, QZSS and SBAS. Its advanced satellite-tracking technology ensures it works well even in harsh environments, such as under heavy foliage or close to buildings.
A third-generation inertial measurement unit (IMU) makes the N2 immune to magnetic disturbance, which greatly improves its reliability. Pole-tilt compensation of up to 60° allows surveyors to locate difficult points precisely and easily while maintaining positioning accuracy within 2.5 cm. By using the company’s Quantum algorithm, the N2 achieves calibration-free operation — after 10 seconds of initialization, users can make tilt measurements with centimeter-level accuracy for an extended period, greatly improving efficiency.
With its integrated UHF modem, the N2 can reach a working range of up to 15 km. It can be used as either a base station or a rover.
The N2 features a 10,000 mAh intelligent Li-ion battery, along with ComNav’s patented low-power-consumption technology. It fully charges in five hours and works continuously in the field for 20 hours. The built-in USB-C port makes it convenient to charge with standard smartphone chargers or external power banks.
As with ComNav’s other products, the N2 meets ComNav’s high quality and durability standards; it is rated IP67 (dustproof and waterproof) and can work in temperatures from –35° C to +65° C. It can be used in a wider range of outdoor working conditions.
With near-field communication (NFC), the N2 can connect to other NFC-enabled devices, such as the R60 data collector. V5.0 dual-mode Bluetooth inside allows users to connect at ultra-long distances with low energy requirements.
The N2 Palm RTK GNSS receiver now is available through ComNav Technology authorized local distributors or directly from ComNav Technology.
