My January 2025 GPS World newsletter mentioned that the National Geodetic Survey (NGS) made several updates to the North American-Pacific Geopotential Datum of 2022 (NAPGD2022) products and that these updates are now available on the NGS alpha site. NGS held a webinar on Jan. 9, 2025, to discuss NAPGD2022 and explain the product updates. I highlighted the NGS Alpha site and GEOID2022 — a product of the NAPGD2022 — in my July 2024 newsletter.
This newsletter will highlight the NAPGD2022 alpha site and the components on the Alpha site — GEOID2022, DEFLEC2022, DEM2022 and GRAV2022. See below for a description of the site.
NGS users of the new National Spatial Reference System (NSRS) should determine the impact on their products and services. For example, the effect of using NAPGD2022 orthometric heights instead of the North American Vertical Datum of 1988 (NAVD 88) on flood plain maps and FEMA elevation certificates.
I have experience dealing with the impact of products and services changing from one national vertical datum to another. When I worked for NGS, I was the Project Manager of NAVD 88. The adjusted heights from the NAVD 88 general adjustment were officially published on June 15, 1991. Performing the adjustment of NAVD 88 was a relatively simple task compared to implementing of NAVD 88 in geospatial products and services in the United States. I wrote articles and talked about the change in the datum from the National Geodetic Vertical Datum of 1929 (NGVD 29) to NAVD 88 at surveying and mapping conferences several times a year during the decade before the completion of the adjustment. Many users were still surprised by the change and the impact on their products and services. It’s a little different today because there are more ways of getting the word out in today’s digital world, such as webinars, Zoom meetings and digital magazines. That said, users still need to participate in webinars and Zoom meetings and read digital articles to understand the changes to geospatial products and services.
Users can download gridded files of the models to create their own routines to analyze the models in their region.
Photo: NGS
The site provides an option for users to perform single point interactive computations.
Single point interactive computations. (Photo: NGS)
The differences between the ITRF 2014 (epoch 2010.0) coordinate and ITRF 2020 (epoch 2020.0) in North Carolina are not very large. Still, I used NGS’s HTDP tool to transform the North Carolina Monroe CORS (NCMR) ITRF 2014 (epoch 2010.0) coordinates to ITRF 2020 (epoch 2020.0) and then entered the transformed values into the interactive tool. See the images “HTDP Output for NCMR” and “Interactive Computation Page” for an example of the output of the single-point interactive computation tool.
HTDP output for NCMR. (Photo: NGS) Photo: NGS
I have highlighted the NAPGD2022 orthometric and dynamic heights for NCMR CORS. I downloaded the latest NGS datasheet for the North Carolina Monroe CORS (NCMR) to obtain the published NAVD 88 height. See the image below.
NGS data sheet for Manroe CORS. (Photo: NGS)
In my example, the difference between the NAPGD2022 and NAVD 88 orthometric height is -0.26 meters (174.40 m – 174.66 m). It should be noted that the tool also provides a dynamic height for the mark. Dynamic heights are used by the International Great Lakes Datum (IGLD). My August 2021 GPS World Newsletter provides more information on the update to the IGLD 85 and dynamic heights. The interactive computation page tool also provides the GEOD2022 value for the mark. The difference between GEOID2022 and GEOID18 for the mark is -0.112 meters (-31.428 minus -30.316).
The alpha site provides an option to use an interactive online map that allows users to access GIS maps that depict individual models. I have highlighted the five layers on the box titled “NAPGD2022 Interactive Online Map” – GEOID2022, SDEFLEC2022, GRAV2022 (RBA), Geoid Differences, and NAPGD2022 Differences.
To demonstrate the online maps, I clicked on the layer titled “NAPGD2022 Difference” located in the upper right corner of the of the map. The image below provides a description of the layer.
Photo: NGS
Users can click on the map, and the pop-up provides information about the location. In the example below, the popup provides the difference between the NAPGD2022 orthometric height and the NAVD 88 height.
The difference between NAPGD2022 orthometric height and NAVD 88 height. (Photo: NGS)
Additional information about a layer is provided on the lower left side of the map page.
Additional information for NAPGD2022 difference. (Photo: NGS)
NGS’ online maps didn’t depict the details I wanted to visualize, so I downloaded the data and created my own maps.
I provided a couple of examples of the differences between NAPGD2022 and NAVD 88 below: one for North Carolina and one for Colorado. As you can see from the plots, there are significant relative differences in mountainous regions (western North Carolina and western Colorado), and a lot of local variation across the state.
Differences between NAPGD 2022 orthometric heights and NAVD 88 in North Carolina (2 cm contour intervals). (Photo: Dave Zilkoski) Differences between NAPGD 2022 orthometric heights and NAVD 88 in Colorado (5 cm contour intervals). (Photo: Dave Zilkoski)
I used the same process to determine the differences between GEOID2022 and GEOID18. See the images titled “Differences between GEOID2022 and GEOID18 in North Carolina” and “Differences between GEOID 2022 and GEOID 18 in Colorado.” Again, it should be noted that there is a lot of variation across the state.
Differences between GEOID2022 and GEOID18 in North Carolina (2 cm contour intervals). (Photo: Dave Zilkoski) Differences between GEOID 2022 and GEOID 18 in Colorado (5 cm contour intervals). (Photo: Dave Zilkoski)
In summary, in a few months, NGS will be releasing a Beta version of the new terrestrial reference frames and geopotential datum. This newsletter highlighted the NAPGD2022 alpha site and the components on the Alpha site — GEOID2022, DEFLEC2022, DEM2022, and GRAV2022. I did a 4-part series in my GPS World newsletters in 2017 on the products of NAPGD2022 (June 2017, August 2017, October 2017 and December 2017).
Unicore has introduced the UM981 series, a high-precision positioning module that integrates RTK and inertial navigation system (INS) technologies. The solution leverages GNSS and INS navigation to cater to applications in precision agriculture, surveying and mapping.
The module is compatible with all major navigation systems and frequencies, tracking signals from multiple systems simultaneously for enhanced performance even in challenging environments. Additionally, the UM981 series supports open Precise Point Positioning (PPP) services such as BDS-3 PPP-B2b, Galileo E6 HAS and QZSS L6 MADOCA-PPP, achieving 10 cm positioning accuracy with a convergence time of under 10 minutes, according to Unicore.
The UM981 series processes high-frequency GNSS and IMU data streams efficiently, offering RTCM data transmission at up to 20 Hz, single-point positioning and RTK at up to 50 Hz and integrated navigation data and IMU raw data at up to 100 Hz. These capabilities make it suitable for dynamic scenarios requiring high precision.
In precision agriculture, the UM981 module simplifies machinery auto-steering systems by enabling single-antenna positioning and attitude determination through advanced MEMS technology. At speeds above 1 km/h, it achieves heading accuracy better than 0.3° and roll/pitch measurements better than 0.2°, with accuracy improving as speed increases. The module supports CAN Bus communication and can be customized to work with the ISOBUS Protocol, eliminating the need for switching between interfaces during serial port communication.
For surveying and mapping applications, the UM981S variant delivers high-accuracy positioning and tilt measurement using GNSS and INS fusion algorithms. It eliminates traditional shake-to-start requirements with a walk-and-go feature that allows users to initialize tilt measurement simply by walking with the measurement pole. The module provides 2.5 cm accuracy within a 30° tilt range and supports measurements at larger angles up to 120°, making it suitable for complex environments such as building corners or areas under tree canopies.
Saildrone has equipped its Voyager platform with new hardware and software algorithms, allowing it to operate in areas affected by GPS jamming and spoofing.
The company successfully demonstrated these capabilities in the Middle East, showcasing its ability to function autonomously in GPS-denied environments. According to Saildrone, the tests addressed challenges posed by regional electronic warfare tactics, such as jamming and spoofing, which have disrupted unmanned systems in contested maritime zones.
Task Force 59, established by the U.S. Navy in 2021 under NAVCENT and the Fifth Fleet, has been instrumental in integrating unmanned systems and artificial intelligence into fleet operations. Saildrone engineers developed a localization solution that does not rely solely on satellite navigation, offering seamless operation even in denied environments. This capability was demonstrated during IMX 2025, where Saildrone’s Voyager platform stood out as the sole unmanned vessel capable of persistent surveillance under such conditions.
Saildrone USVs are actively conducting wide-area surveillance across the CENTCOM area of responsibility, enhancing maritime domain awareness and supporting U.S. Navy operations. These efforts align with Operation Prosperity Guardian, which has been safeguarding commercial shipping and countering regional threats since December 2023.
Saildrone is now in its fourth year of collaboration with the U.S. Navy, with its unmanned surface vehicles deployed across various regions, including the Middle East, Atlantic, Caribbean and Pacific Oceans.
The Federal Communications Commission (FCC) has issued a Notice of Inquiry (NOI) seeking public input on positioning, navigation and timing (PNT) systems and policies. While GPS is crucial for the United States’ economic and national security, its dependency as a single point of failure renders it vulnerable to disruption or manipulation by adversaries. Recognizing this vulnerability, leaders such as President Trump, Chairman Cruz, and Senator Markey have advocated for developing alternative systems to ensure resilient PNT capabilities.
PNT data is integral to countless military, public safety, agricultural, and commercial activities. Given the dependence of the American economy and national security on GPS as the sole PNT source, the agency states that the U.S. government is prioritizing efforts to create robust backup systems that can safeguard essential functions in the event of GPS signal disruptions.
The FCC’s NOI examines how the agency can foster the development of alternative and complementary PNT. It seeks feedback on various emerging PNT technologies being developed by broadcasters, wireless operators, satellite constellations and startups utilizing FCC-licensed spectrum. The inquiry also addresses tradeoffs among these technologies based on performance, scalability, geographic coverage, durability, cost and commercialization potential.
The Commission aims to establish a comprehensive record to guide its actions in enhancing GPS resilience and promoting alternative PNT solutions. Potential measures include regulatory changes, public-private partnerships, testbeds, Innovation Zones and other initiatives.
Two PNT-related petitions are currently under FCC consideration. NextNav has proposed allocating approximately $5 billion worth of spectrum to collaborate with telecom providers in establishing a PNT network. Meanwhile, the National Association of Broadcasters (NAB) has suggested adopting a new TV signal format capable of transmitting PNT information without requesting additional spectrum allocation. Insights from the NOI will help inform decisions on these proposals.
The FCC’s inquiry reflects growing concerns about reliance on GPS as a single system for PNT data. By fostering alternatives like terrestrial networks or broadcast-based solutions such as NAB’s Broadcast Positioning System, the Commission seeks to strengthen national resilience against potential disruptions to critical infrastructure and services.
ComNav Technology has released the SV600 unmanned surface vessel (USV) for hydrographic surveying. This remote-controlled vessel incorporates adaptive water-flow straight-line and hovering technology, enhancing efficiency and ease of operation.
A key feature of the SV600 is its dual-moon pool design, which allows for simultaneous deployment of various surveying equipment. This includes Acoustic Doppler current profilers, single-beam echo sounders, side-scan sonar, pipeline detectors and miniaturized multi-beam echo sounders.
The vessel’s design prioritizes versatility and quick transitions between tasks. Its rapid installation feature facilitates seamless switching between different measurement modes, streamlining the surveying process, according to ComNav.
ComNav Technology has revealed the LS600, a handheld 3D laser scanner that integrates SLAM technology, a built-in RTK module and dual 16MP wide-angle cameras. The device employs multi-sensor fusion, including lidar, IMU and cameras, to deliver high performance in both indoor and outdoor environments. It offers 16- or 32-line lidar options, with a scanning range of up to 300 m and a speed of 640,000 points per second for rapid data collection.
The LS600 features an advanced GNSS module that provides centimeter-level accuracy with full-frequency GNSS support. A built-in surveying antenna enhances signal reliability. The dual-lens camera, combined with visual SLAM (V-SLAM), produces detailed color point clouds for realistic and precise visuals. The scanner supports both backpack and pole configurations, making it versatile for applications such as land surveying, engineering, urban renewal, mining, agriculture, forestry and emergency response.
Its automated post-processing capabilities — such as stitching, denoising, and rendering — along with flexible coordinate systems streamline workflows and ensure accurate results. This design allows professionals to achieve precision and efficiency in the field.
Inertial Labs, a VIAVI Solutions Inc. Company, has introduced the M-AJ-QUATRO anti-jamming antenna system, designed to ensure assured positioning, navigation and timing (A-PNT) in GNSS-challenged environments. The system incorporates advanced Controlled Reception Pattern Antenna (CRPA) technology and digital processing capabilities, making it suitable for applications ranging from military operations to commercial aviation.
PNT services are increasingly critical for various sectors, including transportation, telecommunications, artificial intelligence, hyperscale data centers, energy, finance and defense. As GNSS jamming and spoofing threats grow, government agencies and industry leaders are working to address these challenges. For instance, the Federal Aviation Administration and Naval Air Warfare Center Aircraft Division are expediting approval processes for CRPA technology to enhance aviation safety and counter GPS interference.
The M-AJ-QUATRO supports the L1, L2, and L5 GNSS bands and offers robust interference suppression capabilities. Its adaptive digital nulling feature automatically mitigates jamming signals with over 34dB+ suppression in the export-free version and over 45dB+ suppression in the export-controlled version. Additionally, the system can identify and locate sources of interference through its jammer direction-finding capability, improving situational awareness.
It is compatible with multiple GNSS constellations to provide comprehensive global coverage. It employs dual FPGA-based encryption and anti-spoofing technologies for secure signal processing and data integrity. Built to meet stringent military standards like MIL-STD-810G and MIL-STD-461F, the M-AJ-QUATRO is engineered to withstand extreme conditions, making it an ideal solution for defense and aerospace applications.
ComNav Technology has upgraded its Survey Smart software, enhancing its power, user-friendliness, compatibility, file sharing capabilities, CAD engine and surveying performance.
The update introduces a new user interface optimized based on user habits. It features a new visualization interface, a restructured CAD layout and a flexible toolbar that consolidates common functions across scenarios.
ComNav’s self-developed core component, CADX, has been upgraded to enable instant loading of large drawings for smooth operation. The SinoGeoX feature seamlessly integrates CAD with maps. A new Standing Survey feature has been added to the IMU mode. When activated, it automatically measures points after the receiver remains stationary for 2 seconds, eliminating the need for manual clicks.
File sharing capabilities have been enhanced, allowing files to be downloaded via QR code scanning on handheld collectors or other devices. One-click transfers between collectors, smartphones, and PCs enable cross-platform collaboration and rapid sharing.
The software also now includes RTK PPP Fusion, which seamlessly switches to PPP solutions when RTK signals drop. This maintains operational continuity with PPP accuracy up to 20 cm. It supports echo sounders for precise depth data and WMS services for synchronized, customizable map data.
ComNav Technology has introduced the Jupiter Laser RTK, which is designed for surveying and stakeout operations. The system offers a range of up to 50 m with centimeter-level accuracy and eliminates the need for traditional poles for efficient performance in routine and complex environments.
Equipped with a global night vision camera and laser technology, the Jupiter Laser RTK maintains high efficiency even in low-light or nighttime conditions. Its laser remains visible in the dark, enhancing usability during survey and stakeout tasks. The system also features visualized capabilities through a handheld data collector with an intuitive interface. Users can easily view point positions and follow directional arrows and real-time distances via Survey Master software’s 3D visual interface to accurately mark stakeout points.
The dual-camera system further enhances precision by guiding stakeout paths with a front camera for long-distance views and switching to a bottom camera for close-range detail. A flashing laser replaces traditional walkie-talkies near stakeout points, while visualization compensates for the laser’s invisibility in bright light or over long distances. These features improve efficiency by up to 30%.
Jupiter Laser RTK incorporates cutting-edge technologies such as the K8 board, which tracks up to 1,668 channels across all satellite constellations for reliable positioning. Its Super Datalink supports a 15 km working range and full-protocol compatibility, while Auto IMU provides tilt compensation up to 120° without manual initialization. Designed for durability, the system is waterproof, drop-resistant, and equipped with long battery life, ensuring reliable performance in diverse environments.
An early 1900s Italian folk song tells of a farmer walking into his fields at dawn to spread wheat seeds with his hand from a small bag.1 Farming has changed quite a bit since then. After remaining essentially unchanged for about 12 millennia, in the past century, it has been transformed by such innovations as tractors, electrification, chemical fertilizers and pesticides. In the 1990s, precision agriculture (PA) emerged. (This magazine produced a few supplements on the subject around 1999. If you still have any of them, please let me know.)
PA reduces inputs of water, fertilizer, seeds, pesticides and fuel and increases harvests by mapping variations in soil characteristics and plant health and then using those maps to adjust the inputs using variable rate technology on sprayers. It also ensures that no part of a field is sprayed twice or missed and greatly reduces overlap in seeding and tilling. Double spraying is costly and wasteful; missing a row when spraying pesticide can cause pests to concentrate there and then spread, nullifying a whole spraying operation.
The data for the maps are gathered from sensors on tractors and other farm machinery in the fields, as well as by aerial platforms — nowadays, mostly UAVs. GNSS receivers are essential in guiding the farm machinery. The required accuracy depends on the crop but is typically at the centimeter to decimeter level.
Increasingly, farm machinery also incorporates a variety of other sensors, both to compensate for GNSS outages and to minimize the risk of collisions, such as when a cow crosses the path of a tractor. To maintain navigation during GNSS outages, inertial navigation is used. For obstacle avoidance lidar, radar and stereo vision cameras are used to measure the distance to the object. (Both challenges — navigation in GNSS-denied areas and obstacle avoidance — and their solutions are very similar to those encountered with autonomous vehicles on roads.)
In-cab displays enable growers to monitor their progress in real time. They often also download the data and maps to a laptop to better identify missed spots or areas with special issues and to plan their next task.
Manufacturers of PA equipment compete in a global market. Some challenges are the same everywhere, while some are specific — such as strong ionospheric scintillations in Brazil or antiquated agricultural practices in Japan’s Furano region. For this year’s cover story on PA, I discussed these challenges and the latest generation of farming hardware, software and services with
■Kirstin Schauble, director of systems engineering, ANELLO Photonics
■ Joey Koebelen, founder and CEO, Deep Sand Technology
■ Chad Huedepohl, PA portfolio manager, autonomy and positioning division, Hexagon
■ Ken MacLeod, director of product management and Gordon Echlin, director of business development, Calian GNSS.
This article contains a few excerpts from those interviews. I also received case studies from AgLeader Technology, ComNav Technology and Harxon Corporation.
ANELLO Photonics makes silicon photonics optical gyroscopes, which enable accurate dead reckoning without GNSS and are targeted mostly at the autonomy market. (Anello means ring in Italian, which reflects the nature of the company’s technology and the Italian-American background of its CEO, Mario Paniccia.) Because ANELLO specializes in high precision in situations with obstructed GNSS signals, orchard cultivation is one of the agricultural practices in which it specializes. “Orchards have high-value crops, such as almonds or walnuts, and you’re driving your tractor between very narrow rows with trees completely covering the sky above you,” Schauble said. “Our job is to replace that GNSS input with our inertial navigation system (INS) input.”
Deep Sand Technology — in partnership with GEODNET, the largest real-time kinematic (RTK) network in the world — sells affordable RTK corrections to farmers. It also maintains and troubleshoots the system, compensated by the network’s cryptocurrency. “We handle the blockchain and use it for maintenance,” said Koebelen. “We have someone that checks every day and makes sure that the bases are up. We do the support on it. Instead of charging for that, we take the tokens; that’s just our part of the program, and they get free RTK.” Koebelen, who is also a peanut farmer, adds: “You can trust anything that we sell because it has been tested and used by a farmer and is supported by a farmer.”
Hexagon, a very large company, makes a wide range of sensors that capture and display data about physical reality. Its latest contributions to PA include the TerraStar-C PRO and the TerraStar-X Corn Belt corrections services, which incorporate improvements in ionospheric resiliency. “Especially in the Brazil market, some growers were often experiencing hours of downtime due to ionospheric scintillation,” said Huedepohl. “With the ionospheric enhancements that we’ve added, that downtime now is down to just a few minutes here and there.” He also cites safety enhancements for the autonomy market, such as dual antenna solutions and geofencing.
Calian GNSS is a global supplier of technical solutions, services and products to the space communications, defense, wired and terrestrial wireless, manufacturing, GNSS, agricultural technology and nuclear industries. The company’s recent entries in the PA market include GNSS antennas with lower elevation gain and extended filtering. “Our GNSS agriculture antennas support centimeter level precision, have best in class lower elevation angle gain enabling L-Band correction reception (at northern and southern latitudes), and have eXtended Filtering (XF), which creates very deep attenuation of nearby out of band radio frequency signals,” said Echlin. “Having a digital signal from the antenna to the smart ag controller simplifies and reduces the cost of the installation,” said MacLeod.
Ag Leader, founded in 1992 and focused exclusively on precision farming technology, offers a complete line of systems that integrate with existing farm machinery. In February, it introduced the RightPath passive implement steering solution to alleviate the problem of trailed implements drifting off the guidance line by up to 10 inches or more, even when farmers utilize auto steer and on flat ground. RightPath keeps implements centered on the guidance line, ensuring precise input placement and increasing operational efficiency throughout the growing season while minimizing crop damage, yield loss and operator challenges, Ag Leader said. To utilize RightPath, both the vehicle and the implement require Ag Leader’s GPS 7500, but only the vehicle needs to be equipped with TerraStar-C, TerraStar-X, or RTK. RightPath will be available in late fall 2025 through a single purchase unlock and without any recurring subscription fee.
ComNav Technology is an original equipment manufacturer (OEM) that develops and manufactures GNSS OEM boards, receivers and solutions for high-precision positioning applications worldwide. Japan’s Furano region is renowned for its vast farmland and abundant agricultural resources. Still, it is challenged by traditional manual driving methods that provide insufficient accuracy, low efficiency, and operator fatigue during prolonged tasks. To address these issues, ComNav introduced the AG502 autosteer system, which integrates satellite reception, positioning, navigation and autonomous driving. It is compatible with a variety of mainstream tractors on the market and is suitable for a wide range of agricultural tasks such as ridging, seeding, spraying and harvesting, ComNav said. In the Furano project, the AG502 demonstrated its versatility through its successful deployment on a transplanting machine.
Harxon Corporation makes GNSS positioning antenna solutions. The company has been collaborating with Brazilian agricultural navigation solutions and systems developer Agres to integrate Harxon’s Smart Antenna into the AgresAutopilot System. This secure and robust agricultural navigation solution has been widely adopted by Brazilian agribusinesses to provide automatic steering on straight or curved parallel lines to assist with such field operations as preparing the soil, planting seeds, cultivating the plantation and harvesting the crops. These systems are suitable for various brands and tractor/vehicle models such as Kuhn, John Deere, Valtra, Massey Ferguson, New Holland, LS, Landini, Jacto and others.
To maximize an operator’s turning accuracy and efficiency, Ag Leader introduced TurnPath, hands-free steering for automatic, repeatable end-of-row turns. (Photo: Ag Leader)
Challenges
The key technical challenges faced by PA systems include minimizing multipath and RF interference and monitoring the positions of implements relative to the tractor. “Agriculture requires positional accuracy, so mounting an antenna on a farm machine is not a trivial matter,” said MacLeod. “On metallic machinery, radio frequency surface currents and reflections (multipath) will degrade the antenna radiation pattern, and RF noise coming from other electronics on the machine can interfere with GNSS.” Additionally, because most GNSS applications now are full band, “the challenge is designing antennas that are small and full band, and which also reduce local multipath on the machine.”
Regarding the position of the implements, MacLeod said: “Many agricultural applications use the moving base technique to estimate a precise heading which can be used to monitor pass to pass overlap. Calian GNSS have smart antennas that support the moving base application.”
Accuracy and Reliability
Nearly all PA practices require RTK, which gives repeatable accuracy of 1 cm to 2 cm. “I have this conversation daily with farmers,” Koebelen said. “All crops or farm practices benefit from RTK, even if you’re just doing hay work — whether you’re planting or harvesting. We can’t control the weather, commodity prices, or fuel prices but we can reduce input costs. So even if you’re just tilling, GEODNET RTK will pay for itself and is better than using traditional autosteer, because you’re eliminating all overlap.”
Additionally, farmers need reliable repeatability, even from one season to the next, to be able to return to the same spot to harvest what they planted. “Peanut farmers may plant with RTX or SF3, but satellite-based corrections, even higher precision ones, didn’t provide them enough repeatability to come back to harvest,” said Koebelen. “So, they still had to adjust their lines or hand-drive them. If the spacing between passes are off by even two to three inches, you’re going to lose peanuts. That’s why peanut farmers — as well as growers of potatoes, cucumbers, and other crops — need RTK.”
Once they enter a GNSS-denied area, such as an orchard, farm machines will need a dead reckoning capability that can keep them within a 20 cm to 30 cm error, said Schauble. “This is typically posed as a cross-track error. Errors in the direction of the distance traveled are slightly less important, because you can tell based on visuals when you exit a row.”
Growers think of reliability, accuracy and repeatability in terms of whether they can count on a system to do what they are asking it to do, Huedepohl explained. “They think about all those things. They do not necessarily focus on one thing versus another.”
Retrofitting
While many agricultural systems are proprietary, there is also a lot of mixing-and-matching and retrofitting going on. More than 90% of new tractors come with factory-installed guidance, but some growers want to retrofit new receivers on their machines, either because they did not have them or to upgrade. On some machines, it is possible to feed better positioning data — for example, integrating GNSS and inertial navigation — into the port that previously took in only GNSS data, using a standard NMEA format.
“It’s a simple plug-and-play to exchange someone’s GNSS receiver with our INS solution. Obviously, they need to do some testing to optimize placement, installation and stuff like that,” said Schauble. “Many companies are retrofitting existing tractors with an autonomy stack. They take commercial off-the-shelf (COTS) systems, such as ours, or a lidar or a camera, and retrofit a tractor. That’s their business model.”
The AG502 autosteer system being tested and calibrated on a transplanter in Japan’s Furano region, which is renowned for its vast farmland. (Photo: ComNav Technology)
Additional Sensors
Among the additional sensors often used are wheel odometers. “Without the wheel speed, you’re relying heavily on accelerometers,” said Schauble. “Growers cannot afford to pay $100,000 for a reference-grade system. The navigation systems for these applications use MEMS accelerometers, as we do. So, wheel speed aiding is extremely important to maintain that distance traveled.”
Integrating GNSS and inertial measurement units (IMUs) has long been standard. Increasingly, this integration is done inside an antenna, called a smart antenna. Calian, among others, does that. “We also have smart antennas that employ the L1-L5 observation pair rather than L1-L2, since the L5 signal is stronger and performs better under cover,” said MacLeod. “L5 uses an enhanced signal architecture with 10x faster chipping rate (10.23 MHz) offering more precise standard localization and improved multipath mitigation for reflections exceeding 29.3 m.”
Corrections
Corrections have also been key to the evolution of PA. A reference base station can provide 1-inch accuracy for up to 21 miles, degrading beyond that distance. It needs a WiFi network to communicate, so farmers often place the base station near their home and connect it to their home network. “We haven’t found an internet connection that isn’t quick enough to handle that,” said Koebelen. “From there, you can use your hotspot with a SIM card on your phone, and it’s like texting, so it will not drop like with voice calls. We haven’t run across rural areas where cell coverage is the limiting factor.”
RTK adoption is growing among farmers. “In the past, many people did not want to use RTK, because it was not very affordable nor easy,” Koebelen said. “However, now that we have these networks [such as GEODNET], you’re going to see a lot more people rely on the precision of RTK and you’re going to see many new products come out. Right now, even John Deere, Trimble and other major brands that are more expensive are trying to make the tier below RTK more affordable or easier to get — for example, RTX, SF3, the satellite-based corrections.” GEODNET’s network is growing rapidly, he said, “because our price for RTK is lower than Trimble’s or John Deere’s basic entries, which use free satellite signals that drift throughout the day.”
Huedepohl agrees that RTK has improved while prices have dropped significantly. “Earlier in my career,” he said, “RTK positioning was very expensive and satellite-based augmentation systems (SBAS) were not as stable. Also, RTK systems and such used a single constellation for the longest time. We started adding in GLONASS and then positioning network (Ntrip) corrections, which gave us a lot more robustness.”
Precise point positioning (PPP) has also improved. It used to have convergence times of up to 45 minutes. “Then, you would drive underneath one tree on the edge of a field, and you had to start all over,” Huedepohl recalls. “That did not sit well with farmers, so PPP corrections struggled to take off. Because of those early experiences, it took a long time for the market to start to accept the newer PPP models that we’ve seen in the past seven or eight years. Now there are farmers who enjoy the reliability of those PPP corrections.” The convergence time for one of Hexagon’s PPP services, TerraStar-C PRO, is often less than five minutes, according to Huedepohl. “We have a fast startup time. So, if the tractor was shut down, already converged and you turn it back on, most people are going to be reconverged in just a minute or two.”
Harxon enables autonomous agricultural applications with GNSS antennas, smart antennas and wireless data radios. (Photo: Harxon)
Division of Labor
The division of labor between manufacturers of PA equipment depends, in part, on whether a system is a retrofit or built from scratch. “If you are, let’s say, John Deere, and you own the entire autonomy stack within this tractor, then you can take our INS solution, add cameras, maybe add a lidar, and you can have your own fusion of those sensors,” said Schauble. “We have our own sensor fusion with IMUs and GPS. The tractor’s autonomy stack can do the sensor fusion with our output and other visual sensors, such as cameras and lidars.”
“Dealerships want their tractors to be known as having the highest tech,” said Schauble. “For a dealership to offer our state of the art, autonomy-enabling technology would be a huge benefit to them.”
Another differentiator is whether a factory-installed system is an OEM or branded. “We’ve been providing NovAtel branded receivers to AGCO for many years, through their channel, both factory-installed and aftermarket. Some of the others, such as CNH, are white labeled, so it would just say ‘Case-IH’ or ‘New Holland’ and have no Hexagon markings.”
Whether OEM or aftermarket, most manufacturers have some type of proprietary integration. “There are products that are just NEMA; they are typically at the lower end and priced much lower,” said Huedepohl. “The higher performing flagship products out of everybody’s portfolio are usually doing a more customized integration.”
Echlin has a similar perspective: “We provide products to OEMs who designed our products into their machinery. There are also system integrators and aftermarket system providers that use our smart antennas.”
According to Harxon, one reason for the success of its smart antenna in the agriculture market, especially for autonomy users, has been its ease of integration and high performance. “GNSS positioning is just one part of an autonomous system, and the autonomous integrators don’t necessarily have resources or expertise to develop an OEM component portfolio. Therefore, it’s a timesaving and cost-effective choice to directly integrate a smart antenna into an autonomous system.”
1 “Di buon mattino il contadino va nei suoi campi a seminare il grano. Ha un sacchettino e ci tuffa la mano.”
■ The term precision agriculture emerged when yield monitoring was first invented and brought to market.
■ GPS receivers were added to map the sources of the yields, which began to make it possible to manage farmland and zones based on productivity.
■ This very quickly evolved into also mapping soil sampling results and directly tying that type of information to point-specific yield information from a field.
■ After several years, variable rate application of fertilizer emerged.
■ In the mid-2000s, auto-swath technology came on the market, making it possible to turn on and off the different implement sections on application equipment — primarily, sprayers and spreaders.
■ In the mid-2000s, autosteering systems started to become standard on newer equipment and soon became a key product in the aftermarket. This gave farmers better efficiency and helped provide them more hours of productivity per day. It also allowed them to pay better attention to the equipment and the application that they were set up to do.
■ The combination of swath control and auto guidance greatly accelerated the development of precision agriculture, eventually leading to the monitoring and control of planter equipment.
■ More recently, the trend toward autonomy began, with greater focus on live sensors, including camera imagery.
An exclusive interview with Joey Koebelen, Founder and CEO at Deep Sand Technology. Read the full story and additional exclusive interviews here.
When and why did you found Deep Sand Technology?
About five years ago. I was looking for an affordable RTK system. I was on a smaller farm and had older equipment. I did peanuts. I needed 7-inch accuracy. I looked around. It was $20,000 a system, plus yearly fees, and they didn’t always work on older tractors. So, I came across the FJDynamics system, and I was the first person in the United States to buy it. I was blown away, because it was a third of the cost of other RTK autosteering systems and great quality. John Deere, Trimble, Outback and Ag Leader asked me what I thought about it and, at the time, the only thing I lacked was some interface changes to make it more user friendly.
They asked me if I wanted to be an engineer for them to make it happen quicker and work directly with the other engineers. So, I did that for about nine months, and then really saw the opportunity of an affordable high precision auto steering system that could really change the world for farmers. For once, the technology was simple enough to be sold remotely. So, I started selling systems across the United States. Once guys tried it, they were blown away. The also realized that I support everything. Who knows how to support a farmer better than a farmer? So, I built my team directly from that.
Then, as we kept growing, we got in partnership with GEODNET because we had to use radio bases, which were nice but were limited and a little hard to troubleshoot remotely sometimes. Once I heard that they were trying to get RTK in rural areas, it was a no brainer, because that’s where our farmers are. It would help farmers. It got more guys into high precision RTK because there are many farmers out there using autosteer, but they never could afford to use true RTK precision. Now that we’re offering that affordable cost, we can help farmers save time and money.
We’re also going to follow the guidelines on some of these environmental practices that are being pushed. Deep Sand Technology will always sell precision agriculture technology. Anything that we sell you can trust because it has been tested and used by a farmer and is supported by a farmer. We always offer a buyback guarantee.
As a peanut farmer, what was your accuracy requirement?
I needed repeatable 1-inch accuracy, which required RTK. Peanut farmers may plant with RTX or SF3, but satellite-based corrections, even higher precision ones, didn’t provide them enough repeatability to come back in to harvest. So, they still had to adjust their lines or hand-drive them. If the spacing between passes are off by even two to three inches, you’re going to lose peanuts. That’s why peanut farmers — as well as growers of potatoes, cucumbers, and other crops — need RTK.
How dense does the network of base stations need to be?
GEODNET is the largest RTK network in the world. They want to expand into rural areas. As we get customers in these rural areas, if they don’t have a base there, we’re able to offer them one. If they keep power and WiFi to it, they get free RTK. That’s going to strengthen our coverage across the United States and the world.
One base can cover up to 21 miles. So, my base covers me and anyone in that area. That’s for 1-inch accuracy but you still have precision accuracy outside of 21 miles.
There are many overlapping circles, each with a 21-mile radius?
Yep. As I said, that is for 1-inch accuracy. There are many things that don’t always need that accuracy. I have guys that will use it up to 40 miles from the base station. There are 10,000 base stations across the world. We enter the location on a map and often, right now, if it’s a rural area and there aren’t a bunch of bases in there, we include one in their package. That way we can keep strengthening the RTK network.
In the past, many people did not want to use RTK, because it was not very affordable nor easy. However, now that we have these networks, you’re going to see a lot more people rely on the precision of RTK and you’re going to see many new products come out.
Besides peanuts, which crops need the highest accuracy? What are the next two or three levels in accuracy requirements?
I have this conversation daily with farmers. All crops or farm practices benefit from RTK, even if you’re just doing hay work — no matter whether you’re planting or harvesting. We can’t control the weather, commodity prices, or fuel prices but we can reduce input costs. So even if you’re just tilling, tem, like RTK, will pay for itself and is better than using traditional autosteer, because you’re eliminating all overlap.
USDA is spending hundreds of millions of dollars to promote farm practices that need RTK. I’m working with the USDA right now to release these programs that express why RTK plays such a factor, because it’s huge. For example, how do you reduce your chemical and fertilizer costs? The simplest way is to not overlap. Also, with accurate repeatability you can take soil samples and map them. So, now guys can adjust their fertilizer or the chemical rate off these samples, but to do that efficiently they need RTK.
The need for WiFi puts farmers are at the mercy of the big telecom companies.
You don’t need WiFi in the field. You need WiFi for the base station to communicate and we haven’t found an Internet connection that isn’t quick enough to handle that. From there, you can use your hotspot with a SIM card on your phone, and it’s like texting, so it will not drop like with voice calls. We haven’t run across rural areas where cell coverage is the limiting factor.
So, there’s enough coverage everywhere for the base station to get online.
A base station normally has a Starlink connection or whatever Internet connection you have at the house. Starlink is pretty popular nowadays.
How is the adoption of RTK going? Is GEODNET the 800-pound gorilla right now?
Yeah, that’s my opinion. Right now, RTK is getting more adopted, because even John Deere, Trimble and other major brands that are more expensive are trying to make the tier below RTK more affordable or easier to get — for example, RTX, SF3, the satellite-based corrections. We’re having a huge trend, because our price for RTK is lower than Trimble’s or John Deere’s basic entries, which use free satellite signals that drift throughout the day.
Drones are becoming a big thing. I’m starting to see in-row cultivators. There are snowplows, a lot of autonomous options. Plus, I see a lot of construction surveying. We’re about to jump off into that. GEODNET is at the front because one their goals, to offer affordable RTK, aligns with farmers and nobody else really has that.
What about the blockchain aspect of GEODNET?
I think it’s a good program. Farmers would rather have the RTK. We handle the blockchain and use it for maintenance. We have someone that checks every day and makes sure that the bases are up. We log people in if they need another log in. We do the support on it. Instead of charging for that, we take the tokens; that’s just our part of the program, and they get free RTK. It’s a good program and it incentivizes other people. Farmers are skeptical when you start talking about blockchain or crypto. We want them to understand why the RTK data is important.
