The challenge of repairing GNSS stations in Bangladesh is recounted in a Nov. 6 article by Mike Steckler, a researcher with Columbia Climate School.
Steckler has been conducting research in the country for 25 years. He previously installed a continuously operating reference station (CORS) network in the southern region of the country.
Data from the network has enabled study of the tectonic motions of the Earth leading up to earthquakes. It also revealed the sinking of the land in the world’s largest delta to less than 1 mm/y.
“I still find that amazing compared to the days before GNSS became routine,” he writes. “I’ve been at sea where the crew had to use sextants to estimate our position to within 10 miles.”
Of 16 stations running in the country, only three (green) were transmitting data back to the U.S. “I have returned here once again with others to get them working again and add three new stations (white),” Steckler writes.
Steckler was joined by a team from Dhaka University to visit the sites, make repairs and install new equipment.
Map of Bangladesh showing the locations of Steckler’s GNSS sites and regions he is visiting. The green circles are working systems, the red ones need repair, and the white ones are new. The pink circles are monuments with no active system. (Image: Mike Steckler)
Two European Space Agency (ESA) microsatellites will soon be launched to study climate variables linked to water using GNSS reflectometry. The twin HydroGNSS satellites arrived at Vandenberg Space Force Base in California at the end of September, from where they will be launched later this month.
The HydroGNSS twins are the European Space Agency’s first Scout venture, part of the agency’s Earth Observation FutureEO programme. Scout missions are designed to deliver cutting-edge science quickly and affordably, complementing ESA’s larger Earth Explorer missions.
The identical microsatellites will launch from Vandenberg aboard a SpaceX Falcon 9 rocket, sharing their Transporter-15 ride into orbit with several other small satellites.
Since their arrival, the HydroGNSS satellites have undergone a series of final checks — including testing, propellant loading, battery charging and integration with their launch adapter. Both satellites are now ready for closing of the rocket fairing.
Once in orbit, the two satellites will travel 180 degrees apart around Earth to maximize coverage.
The mission focuses on four crucial variables, all recognized as “essential climate variables” or closely related to them: soil moisture, freeze–thaw state over permafrost, inundation and above-ground biomass. These data are vital for improving our understanding of Earth’s water cycle, including wetlands, permafrost dynamics and forest carbon storage. The data will aid in agricultural planning, flood prediction, and others areas.
HydroGNSS satellites will use GNSS reflectometry to measure key hydrological climate variables, including soil moisture, freeze–thaw state over permafrost, inundation and wetlands, and above-ground biomass. (Image: ESA)
Navigation satellites such as GPS and Galileo transmit L-band microwave signals that change when reflected off Earth’s surface. HydroGNSS will compare these reflected signals with the direct GNSS signals to extract valuable information about geophysical parameters related to the water cycle.
New Space missions. Inspired by the principles of New Space, the Scout programme emphasises agility and innovation — using small satellites to miniaturise proven technologies or demonstrate entirely new ways of observing Earth.
Each Scout mission must move from kick-off to launch within just three years and under a budget of €35 million, covering everything from satellite development to in-orbit commissioning. The resulting data are provided as a service to the scientific community and ESA, helping accelerate our understanding of the planet.
Quectel Wireless Solutions, a global IoT solutions provider, launched three smart single board computers Tuesday designed to speed product development and reduce costs.
The QSM368Z, QSM560DR and QSM668SR offer developers connectivity, operating system and memory options for various applications, the company said.
“These boards are fully finished hardware that can be easily integrated inside customers’ larger systems across a wide range of IoT use cases,” said Raymond Wang, head of Smart SoC at Quectel Wireless Solutions. “Provided in a ready-to-use, single, low-cost platform, these boards are helping to simplify and accelerate the development process for IoT devices of all types, significantly reducing development time with rapid prototyping and cutting development costs.”
The QSM368Z features the Rockchip RK3568 IoT processor with a quad-core ARM Cortex-A55 CPU, ARM Mali G52 GPU, 8M ISP HDR and 1 TOPS NPU. The board supports Linux and Android operating systems.
The device includes triple-screen concurrent display support, 1,000 Mbps Ethernet and 4K video encoding. Built-in Wi-Fi 5 and Bluetooth 4.2 come standard, with optional support for Quectel LTE Cat 1, LTE Cat 4, Wi-Fi 6 and GNSS modules.
The QSM368Z measures 120mm x 100mm x 22.25mm, weighs about 90 g and operates in temperatures from -10 C to +75 C. Applications include IoT gateways, smart displays, industrial terminals, safety monitoring systems, NAS, NVR/DVR and automotive NVR solutions.
The QSM560DR features 12 TOPS NPU and supports Ubuntu, Android and Windows. The platform’s multi-mode 5G capability supports both NSA and SA networks, with 3G and 4G fallback. Wi-Fi 6E with DBS and 2×2 MU-MIMO technologies enable faster data transmission.
The device supports downlink speeds up to 2.5 Gbps on 5G NSA. It measures 120.5mm x 106mm x 22.5mm, weighs approximately 120 g and operates from -35 C to +75 C. Target markets include smart manufacturing, retail analytics, robotics and connected infrastructure.
The QSM668SR supports Android, Linux and Ubuntu and features 1.1 TOPS NPU. The board supports LTE Cat 4, Wi-Fi, Bluetooth and GNSS. Under LTE Cat 4, the board achieves uplink speeds up to 150 Mbps and downlink speeds up to 50 Mbps. Bluetooth 5.0 is included.
Optional GNSS functionality provides positioning through GPS, GLONASS, BDS, Galileo, QZSS and SBAS satellite constellations.
The device includes HDMI, camera inputs, Ethernet, UART, USB, I²C, RS232, RS485, CAN, SD and SIM interfaces. It measures 102mm x 100mm x 23mm, weighs approximately 97.7 grams and operates from -20 C to +75 C. Applications include IoT gateways, smart home systems, industrial control terminals, retail solutions, safety monitoring, vehicle equipment and logistics devices.
Quectel also provides antennas for cellular, Wi-Fi, Bluetooth and GNSS networks, plus custom antenna design and optimization services.
Trimble has provided advanced geospatial equipment to Fresno State’s Geomatics Engineering Program in collaboration with California Surveying & Drafting Supply, a Cansel company (CSDS). The equipment is designed to facilitate experiential learning in optical surveying, photogrammetry, GIS, GNSS and scanning workflows, helping to equip geomatics students with the skills needed for future careers. As part of this collaboration, Fresno State will open a Trimble Technology Lab on campus in 2026 as a place for students to get hands-on experience and training.
As the nation’s first four-year, nationally accredited geomatics program and California’s only Accreditation Board for Engineering and Technology-accredited four-year offering, Fresno State has long been a hub for training the geospatial professionals who power land surveying companies throughout the Western U.S., including entities like Caltrans and PG&E. CSDS, with its expertise in bridging academic needs with industry solutions, was instrumental in bringing Trimble on board to expand the program’s equipment inventory, foster innovation and ensure the program’s sustainability as a talent pipeline for California’s geospatial industry.
“This strategic alliance is key to revitalizing and aligning educational offerings with the cutting-edge tools that define the profession,” said Tom Cardenas, senior vice president at CSDS. “Beyond offering students a hands-on learning approach, this project establishes a scalable model for addressing the surveyor shortage through industry and education collaboration. It’s a clear commitment to reshaping the future of geospatial education in California.”
The Bureau of Labor Statistics reports a significant decline from 56,200 employed surveyors in the U.S. in 2010 to 47,770 in 2020. In California, where more than 2,000 surveyors depend on advanced technologies to support a booming construction and utility sector, the shortage poses a tangible threat to projects ranging from highway expansions to renewable energy installations.
“Fresno State is a critical pipeline for California’s geospatial workforce. The collaboration with CSDS and Trimble amplifies our collective mission to align educational offerings with the state-of-the-art tools that meet the demands of a rapidly evolving industry,” said Bryan Gibert, director of sales enablement at Trimble. “This collaboration is about creating an ecosystem that draws in talent and prepares them for immediate impact.”
The equipment includes Trimble GNSS base receivers, data collectors and network capabilities; Trimble S7 robotic total stations; Trimble DiNi digital levels; Trimble X9 3D laser scanners with T10x tablets; and licenses for Trimble Business Center, Trimble RealWorks and other highly technical software such as Trimble’s aerial photogrammetry module for TBC and Trimble eCognition. Trimble also outfitted Fresno State’s Geomatics Engineering program with several C5 mechanical total stations for a complete, turnkey solution. Both Trimble and CSDS provide configuration, calibration and on-site training for the technology.
“We emphasize hands-on training in our facility, complete with high-end computers, advanced distance learning tech and collaborative research projects with local agencies like CSDS,” said Scott Peterson, associate professor and program coordinator of the Geomatics Engineering Program at Fresno State. “While we had solid foundations from previous industry partnerships, we needed to expand with Trimble technologies to align our geomatics education with what the overwhelming majority of California professionals use every day. This turnkey solution, from GNSS to scanners and software, prepares our students for real-world challenges across geomatics and construction, leveraging our control network for practical training.”
Ag Leader has launched RightPath, a passive implement steering solution, to alleviate issues in precision agriculture resulting from drift.
Putting the right seed in the right location with the right fertilizer is critical for farmers, and has led to the wide adoption of technology such as autosteer. However, if the pass-to-pass accuracy isn’t perfect at planting, the crop is vulnerable to damage in subsequent passes, which drags down yield.
Trailed implements are known for drifting off the guidance line even when farmers use autosteer. The result is inaccurate placement of inputs and inconsistent guess rows. This is an issue because accuracy drives yield.
RightPath is designed to operate seamlessly through Ag Leader’s InCommand Go displays. (Image: Ag Leader)
A passive implement steering solution, RightPath keeps implements centered on the guidance line. This not only ensures precise input placement but also increases operational efficiency throughout the growing season, while minimizing crop damage, yield loss, and operator challenges.
RightPath enables farmers to:
place the implement — and therefore rows and inputs — in the right place.
plant seed accurately relative to a previous operation such as strip-till or NH3.
achieve consistent guess rows in all conditions including curves and uneven terrain.
re-use the same guidance line in the next field activity.
reduce stress and fatigue.
RightPath is designed to operate seamlessly through Ag Leader’s InCommand Go displays. In addition, RightPath is compatible with both SteerCommand Z2 and SteadySteer, Ag Leader’s integrated and assisted steering solutions.
While both the vehicle and implement require Ag Leader’s GPS 7500 to utilize RightPath, only the vehicle needs to be equipped with TerraStar-C, TerraStar-L or RTK. This gives an operator the flexibility to choose the right GPS correction for different operational needs.
RightPath is available now through a single purchase unlock, with no recurring subscription fee.
BDStar Navigation subsidiary TruePoint has introduced the TruePoint.CM network real-time kinematic (NRTK) service across Europe, the latest in BDStar’s expansion into international high-precision positioning markets.
Supporting all major GNSS and QZSS, the service is designed to improve signal reliability in complex European environments. TruePoint.CM is built on the company’s chip-cloud integration architecture and works with both BDStar’s Unicore and third-party GNSS hardware through standards-based interfaces.
The service provides wide-area coverage throughout Europe, the company said, offering centimeter-level accuracy with fast convergence times. Before launch, TruePoint conducted extensive validation testing in more than 40 cities across 12 European countries, including more than 300,000 kilometres of dynamic field trials.
The platform uses an adaptive data protocol to reduce bandwidth consumption by up to 70% while maintaining full positioning accuracy, a feature aimed at helping customers reduce operational data costs. Remote diagnostics and over-the-air firmware updates are incorporated to support more efficient device management in the field.
TruePoint.CM operates on a fully redundant cloud infrastructure spanning data sources, data centers and service-delivery interfaces. The system is designed to ensure continuous uptime, backed by a stated service availability of 99.9%.
At launch, the company reported that it has already secured commercial adoption in the European robotic lawn mower market, with additional opportunities expected in autonomous robotics, UAVs, precision agriculture, automotive and consumer IoT.
Swift Navigation and Asensing have announced full compatibility between the Asensing NAV3120 high-precision GNSS positioning module and Swift’s Skylark Precise Positioning Service. Skylark is a cloud-based service that improves the accuracy of GNSS from several meters to a few centimeters.
The widespread deployment of connected and autonomous IoT systems — including smart delivery robots, UAVs, precision agriculture and logistics — demands reliable, centimeter-level positioning that performs consistently across diverse environments and at scale.
Swift’s Skylark Nx RTK, the highest precision variant of Skylark, leverages a proprietary atmospheric model to deliver continuous 1-2 cm accuracy across vast geographic areas, including Western Europe. The carrier-grade network eliminates the need for developers to manage base stations or switch between multiple correction providers, simplifying the deployment of high-precision outdoor robots at scale.
The seamless interoperability between Skylark Nx RTK and Asensing’s NAV3120 module provides customers with a highly reliable, centimeter-accurate solution packaged in a compact, automotive-qualified hardware module. Joint testing demonstrated this high performance, with the solution achieving a sustained 1.7 cm horizontal position error at 95% confidence during a 24-hour period, which significantly accelerates time-to-market for applications requiring the highest level of positioning integrity.
The NAV3120 is full-constellation and quad-frequency signal reception module engineered for demanding applications. Features include:
Automotive-grade. Complies with AEC-Q100 standards for integrated circuits used in automotive applications.
Extreme operating range. Sustains temperatures from -40°C to +105°C.
Compact design. Small size and standard 17 x 22 x 3.1 mm footprint, weighing only 2g.
Efficient power. Low power consumption of just 0.4W.
The integrated solution is available now for use for autonomous mobile robots, UAVs, fleet management, advanced handhelds and wearables, and precision agriculture.
My September GPS World newsletter highlighted the new California Spatial Reference Network, labeled CSRN Epoch 2025.00. These coordinate changes will impact geospatial users across California, and understanding the transition process is important for preparing for the modernized National Spatial Reference System (NSRS), expected to be adopted in 2026.
CSRC, founded in 1997 and formally dedicated in 2001, develops and maintains a modern network of GPS control stations to provide a reliable spatial reference system for California. Created as a partnership of surveyors, engineers, GIS professionals, the National Geodetic Survey (NGS), Caltrans, and the geodetic and geophysical communities, the CSRC’s mission is to produce a self-sustaining, up-to-date geodetic control network for the state.
The CSRC holds Coordinating Council meetings to review CSRC activities and related state surveying and mapping efforts. The box titled “CSRC Coordinating Council 2025 Fall Meeting” lists the agenda for the most recent meeting. I attend these meetings virtually; they are consistently informative and I enjoy participating.
Image: CSRS website
Dr. Yehuda Bock’s Director’s Report (SOPAC/CSRC Director, Dept. IGPP, Scripps Oceanography, UCSD) is available for download from the CSRC website: http://sopac-csrc.ucsd.edu/index.php/csrc-presentations/ (note: large file). At the Fall Coordinating Council Meeting Yehuda opened with a presentation on the new California Spatial Reference Network, CSRN Epoch 2025.00. I encourage readers to download the presentation or read my September GPS World newsletter, which highlighted CSRN Epoch 2025.00. This newsletter will focus on the Geodetic Program at Scripps Institution of Oceanography (SIO).
Image: CSRC website
In my November 2023 GPS World newsletter, I noted NGS’s announcement of the NOAA FY23 Geospatial Modeling Competition awardees. In my March 2024 GPS World newsletter, I highlighted Scripps Institution of Oceanography’s (SIO) proposal. As noted there, Yehuda’s proposal included three activities:
Create a formal Geodesy Program at SIO to address the nationwide deficiency of geodesists. Expand current geophysics curriculum – funding for five graduate students.
Develop an IFDM to supplement the NSRS for users in regions with significant ground motions, using GNSS and InSAR/GNSS displacement fields (funded by NASA projects) and underlying geophysical models. CSRC will exercise the IFDM through its community of public, private and academic users of precise spatial referencing in our challenging region of secular and transient crustal movements.
Investigate a unified vertical reference frame, including a marine geoid optimized to be consistent with the full spectrum of observations from modern gravimetric geoids (e.g., GRAV-D, ICGEM), remotely sensed observations (e.g., SWOT, ICESat-2), in situ ocean observations and assimilating ocean models and the TRF.
As mentioned in the Director’s report, they have initiated bi-weekly geodesy track seminars to discuss research projects related to NGS and other grants. Four videos by students discussing their projects were shown during Yehuda’s presentation.
The following are the titles and presenters of the four research projects:
San Jacinto Fault Zone by Neil Waldhausen
Probing Antarctic basal ice state using airborne geodesy by Briar Conger
Repeat Pass Interferometry by Rubi Garcia Gonzalez
Hydrologic monitoring with GRACE/GRACE-FO by Logan Platt
San Jacinto Fault Zone by Neil Waldhausen
I have included a few bullets summarizing their project and a few captured images from the videos. I would encourage everyone to download the presentation to listen to the short videos by these students. The presentations are only 90 seconds but are very interesting. Readers can contact the speakers through the University to find out more about their research.
Summary of the “San Jacinto Fault Zone” video:
Neil uses GNSS to measure velocities and strain rates around the San Jacinto Fault.
He focused on the Anza gap, a 20-km segment of the fault.
He re-surveyed about 50 monuments that had been occupied over past decades.
His work has lowered uncertainties in many site velocity measurements.
His aim is to further reduce uncertainties in strain-rate and slip-rate estimates to better understand the Anza gap’s mechanics.
San Jacinto Fault Zone by Neil Waldhausen.San Jacinto Fault Zone by Neil Waldhausen.Image: CSRC website
Summary of the “Probing Antarctic Basal Ice State Using Airborne Geodesy” video:
Briar’s project uses gravity and radar data to study basal hydrology — water flow beneath glaciers and ice sheets, including subglacial lakes, channels, and pressure-driven water movement.
He conducted fieldwork on the East Antarctic Ice Sheet during the 2023–24 season.
He collected airborne gravity and GNSS data from a converted DC-3 aircraft.
Data processing uses both PPP and differential positioning methods.
His aim is to improve long-term sea-level rise predictions.
He is also developing a fixed-wing UAV capable of collecting lidar, gravity, and photogrammetry data.
Probing Antarctic Basal Ice State Using Airborne Geodesy by Briar Conger
Probing Antarctic Basal Ice State Using Airborne Geodesy by Briar Conger.Image: CSRC website
Summary of the “Repeat Pass Interferometry” video:
Rubi used repeat-pass interferometry (phase gradient) to map small-scale surface deformation.
The phase gradient is the change in interferometric phase between neighboring pixels; unlike the ambiguous single-pixel phase (wrapped within 2π), the gradient gives a continuous local rate of change useful for analysis.
She compared fractures identified by phase-gradient analyses with historic fracture databases.
Her ongoing work includes applying Andersonian faulting theory to assess whether fractures formed before or after earthquakes.
Andersonian faulting (Anderson’s theory of faulting) is a geological framework for interpreting crustal stress and fault geometry; it’s used to interpret InSAR-measured deformation. While not a method of analysis for InSAR data itself, it serves as a critical interpretive tool for understanding the ground deformation patterns measured by InSAR.
Repeat Pass Interferometry by Rubi Garcia Gonzalez
Repeat Pass Interferometry by Rubi Garcia Gonzalez.Image: CSRC website
Summary of the “Hydrologic monitoring with GRACE/GRACE-FO” video:
Logan described using satellite measurements of tiny changes in Earth’s gravity to track mass movement and better understand groundwater and the water cycle.
He relied on GRACE and GRACE-FO data.
The Gravity Recovery and Climate Experiment (GRACE) and its successor mission, GRACE-Follow On (GRACE-FO), are Earth-observation missions that use twin satellites to precisely map changes in Earth’s gravity field over time. This unique method allows scientists to track the movement of mass, primarily water, around the planet
He used the GRACE data to look at changes in California’s Water storage from 2004 to 2024.
Results indicate a decline due to drought and heavy ground water usage, with more water being stored in northern California than southern California.
This research supports water management, climate-change impact assessment, and strategies for sustainable groundwater use.
Hydrologic Monitoring with GRACE/GRACE-FO by Logan Platt
Hydrologic Monitoring with GRACE/GRACE-FO by Logan Platt.Hydrologic Monitoring with GRACE/GRACE-FO by Logan Platt.Image: CSRC website
A new InSAR textbook, authored by several internationally recognized researchers, was also announced. Funded by the National Geodetic Survey and published Open Access, the book is available for free download. It’s a large file, but anyone working with InSAR data should obtain a copy.
New InSAR Textbook
Image: CSRC website
Table of Contents of New InSAR Textbook
If you’ve read my newsletters, you know I’m passionate about advancing geodesy. I wanted to share one of Yehuda’s slides, “What Geodesy Can Tell Us About Earth,” because the four students are working on projects tied to real-world problems. The slide highlights geodesy’s importance and the many professions that rely on its findings.
What geodesy can tell us about Earth. (Image: CSRC website)
The new FLIR TransponderTech unit will advance GNSS, AIS and VDES technologies for maritime, aerospace and defense markets.
Teledyne Technologies has completed its acquisition of the TransponderTech business from Saab AB. The acquired company, now operating as Teledyne FLIR TransponderTech AB, will become part of Teledyne’s Raymarine, FLIR Marine, ChartWorld and Teledyne CARIS group of maritime technology brands.
Based outside of Linköping, Sweden, the company will market its products and solutions as FLIR TransponderTech. The brand will continue to focus on delivering GNSS, Automatic Identification System (AIS) and VHF Data Exchange System (VDES) technologies.
Going forward, FLIR TransponderTech will be well positioned to continue to pioneer maritime communication solutions for civil and military customers in shipping, marine traffic, airborne and space segments.
Raytheon UK, part of RTX’s Raytheon business, has been awarded a contract to provide orbital analysts in support of the UK’s Space Domain Awareness mission.
Under the contract, the UK Space Agency will gain access to Raytheon UK’s NORSSTrack software, which enhances orbital analysis and operational responsiveness by mapping and tracking satellites, monitoring potential collisions and debris, assessing re-entries and providing critical data for decision-making.
The analysts will be based at a National Space Operations Centre facility at Royal Air Force Base High Wycombe.
As highlighted in the UK’s Strategic Defence Review, space domain awareness is central to protecting critical space assets and strengthening resilience across government, defense and industry. It is considered a vital national capability, ensuring the UK can operate safely, securely and confidently in an increasingly contested space environment.
The newest member of the proven GAJT team means you can protect all your platforms from jamming. Light and small, it’s the best protection per gram you can get. You can even get it as an integrated enclosure (one piece) or a federated solution (separated anti-jam electronics and CRPA), so it is ideal for small platforms, like UAVs.
Accurate localization underpins modern mobility, powering everything from precise rideshare pickups and efficient deliveries to augmented reality and autonomous systems. Yet achieving reliable sub-meter precision with commodity hardware remains one of the field’s central challenges.
A range of technologies are being explored to improve positioning, such as real-time kinematic (RTK) and Precise Point Positioning (PPP) corrections, 5G methods standardized under the 3rd Generation Partnership Project (3GPP), simultaneous localization and mapping (SLAM), light detection and ranging (lidar), inertial measurement units (IMUs), and ultra-wideband (UWB). Each plays a role in specific contexts, but for everyday, mass-market deployment, two paradigms dominate the conversation: visual positioning systems (VPS), which rely on cameras and computer vision to match images against reference databases, and GNSS plus inertial measurement unit (GNSS+IMU) sensor fusion, which integrates satellite positioning with inertial data already present in billions of devices.
These two approaches are not mutually exclusive. VPS works best in dense urban areas where GNSS can struggle, while GNSS+IMU excels in the open environments where VPS has fewer features to recognize. In practice, VPS even depends on GNSS to help narrow the search space in its visual database. That makes the two technologies natural complements, and together they provide the building blocks for the next generation of spatial intelligence.
The Role of VPS
VPS use computer vision to determine position relative to known landmarks. In favorable environments – especially dense, feature-rich urban settings — they can deliver impressive accuracy. VPS has been successfully applied in AR anchoring, pedestrian navigation, and even some indoor mapping, offering a level of precision that is difficult to match with GNSS alone.
At the same time, VPS faces challenges that limit its ability to scale as a standalone universal solution. Maintaining vast libraries of reference imagery requires constant collection and refreshing, even for companies with resources such as Google’s Street View. Keeping cameras active and running neural network matching consumes power and compute, with AR and navigation apps often showing rapid battery drain when vision pipelines are engaged.
Performance can also be fragile, with accuracy dropping in low light, bad weather, or environments with limited features such as open fields or glass-heavy corridors where reflections distort recognition. Because VPS requires continuous camera use, it also raises privacy concerns under regulations like GDPR.
But VPS still fills an important feature set: it works best in exactly the environments where GNSS struggles most. In dense urban areas with abundant visual features but heavy multi-path interference, VPS provides a complementary capability that enhances overall localization performance when paired with GNSS+IMU.
GNSS+IMU Fusion
GNSS provides global reach, but smartphone accuracy typically ranges from 3m to 5 m. This may be adequate for turn-by-turn navigation, but it does not meet the precision required for lane-level guidance, pedestrian navigation or building entrances. Pairing GNSS with IMU data changes that equation by adding orientation and motion context.
Sensor fusion combines GNSS position (x, y, z) with IMU-derived orientation (α, β, γ) to deliver six degrees of freedom (6DoF). In practice, this allows devices to determine not only where they are, but also which way they are facing, which is critical for navigation and AR anchoring.
Another key advantage is that fusion also runs efficiently on-device, using low-power sensors already embedded in nearly every phone. It avoids the battery drain and compute overhead of vision-based methods, remains resilient in poor visibility, and largely sidesteps the privacy concerns associated with continuous camera use.
Together, GNSS+IMU and VPS offer complementary strengths: GNSS+IMU provides scalable global coverage, while VPS adds value in dense urban or visually rich environments. Used in tandem, they extend reliable sub-meter localization across a far wider range of real-world scenarios.
Performance in Field Tests
Independent field testing has underscored the impact of GNSS+IMU fusion in real-world conditions. In trials conducted in Louisville, Colorado, standard smartphones relying solely on GNSS averaged ~1.9 meters of error. When collaborative corrections and IMU fusion were added, mean error dropped to ~0.55 meters – a more than threefold improvement.
To benchmark localization performance against visual methods, we compared heading determination from Zephr’s sensor-based approach with Google’s VPS, widely considered an industry leader in vision-based localization. Using the same device and location, headings generated from ArPose and Zephr were plotted against VPS outputs.
Figure 1: The figure shows a strong correlation, with a mean heading difference of just 7.58° and a heading correlation of 99.52%.
The results in Figure 1 show a strong correlation, with a mean heading difference of just 7.58 degrees and a heading correlation of 99.52%. This provides a useful benchmark, illustrating that sensor-based approaches can achieve heading accuracy on par with vision-based systems while avoiding the data, compute, and privacy burdens tied to continuous camera use.
Head-to-Head Comparison
When considered side by side, VPS and GNSS+IMU reveal distinct strengths. VPS delivers high accuracy in dense urban environments, where GNSS can be degraded by multipath or blockage. GNSS+IMU, meanwhile, provides consistent global coverage and efficient performance in open environments where VPS has fewer features to recognize. Taken together, they form a complementary toolset, with each addressing the other’s gaps.
Cost & Infrastructure: VPS offers detailed visual positioning but requires continuous investment in capturing and updating reference imagery, which can run into petabytes of data and demand large-scale cloud storage. GNSS+IMU leverages existing satellite constellations and commodity sensors already embedded in smartphones, scaling naturally without additional infrastructure.
Battery & Compute: VPS enables precise landmark recognition but must keep cameras active and process high-resolution frames, a pipeline that consumes energy and compute. GNSS+IMU fuses lightweight sensor readings on-device, sustaining real-time performance with minimal power. Hybrid systems can use VPS selectively for visual anchors when power budgets allow.
Environmental Robustness: VPS excels in dense urban cores where landmarks are abundant, but its performance can degrade in low light, heavy weather, or feature-poor settings such as highways or open fields. GNSS+IMU continues to perform in most outdoor environments, with IMUs bridging short GNSS gaps in tunnels or urban canyons. Together, they extend reliable coverage across diverse conditions.
Privacy: VPS provides visual context but depends on continuous camera feeds, which can raise concerns under regulations like GDPR and CCPA. GNSS+IMU relies solely on inertial and satellite data, which can be anonymized and processed on-device. Privacy-conscious applications may favor GNSS+IMU as the default, while invoking VPS in controlled contexts.
Scalability: VPS delivers strong results in mapped geographies but is constrained by the cost of collecting and maintaining visual data globally. GNSS+IMU scales as more devices ship with standard GNSS receivers and inertial sensors, with accuracy improving further when devices contribute corrections to a shared network. In combination, VPS can add value in high-density urban corridors where visual richness offsets its infrastructure demands.
Beyond Accuracy: Spatial Intelligence Without Cameras
GNSS+IMU fusion not only narrows positioning error but also provides contextual awareness. By combining positional vectors with device orientation, systems can determine not just where a device is, but what lies within its field of view.
This contextual layer enables landmark-aware navigation and natural AI interactions. Instead of vague coordinates, users could be guided to “meet at the blue mailbox next to the coffee shop entrance.” In AR, digital content can be anchored to the physical world without the overhead of vision-based methods. And for AI interfaces, assistants could answer spatial queries (“Is the restaurant to my right or left?”) with precision that feels intuitive.
While GNSS+IMU avoids reliance on cameras, VPS can still add complementary value by providing visual anchors in feature-rich spaces. Used together, the two methods create a more resilient and adaptive localization system, able to support a wider range of real-world scenarios than either could alone.
A Clearer Path Forward
VPS has proven valuable in research, robotics, and AR demonstrations, particularly in dense urban environments. But its reliance on imagery, heavy compute, and continuous camera use makes it difficult to scale as a universal solution for sub-meter accuracy.
To unlock the next generation of spatially intelligent applications, from context-aware assistants to immersive AR, localization must be both practical and massively scalable. This foundation will come from GNSS+IMU sensor fusion, complemented by vision-based methods where they add value. GNSS+IMU builds on infrastructure and sensors already present in billions of devices, delivers efficient on-device performance, and avoids the privacy tradeoffs of camera-based systems.
As positioning becomes the backbone of spatial AI, the evidence points to a decisive outcome: the future will be multimodal, but the scalable backbone will be GNSS+IMU fusion since it empowers devices to understand and interact with the world reliably, with or without cameras.
