From Dec. 4-5, 2024, the National Space-Based Positioning, Navigation and Timing (PNT) Advisory Board met to discuss GPS-related topics. The PNT Advisory Board provides independent advice to the U.S. government on GPS-related policy, planning, program management and funding profiles in relation to the current state of national and international satellite navigation services. A March 28, 2024, GPS World article by Dana Goward highlighted that the PNT Advisory Board has been providing the government with independent expert advice about GPS and PNT for 20 years. He highlighted that the Board is chaired by retired Admiral Thad Allen and has six subcommittees.
This newsletter will highlight a topic that the emerging capabilities, applications and sectors subcommittee discussed at the final PNT Advisory Board meeting of 2024. The presentation title is “GPS High Accuracy and Robustness Service (HARS).” A white paper on the topic and the Dec. 4, 2024, presentation by Shachak Pe’eri, Ph.D., NOAA/NOS/National Geodetic Survey (NGS), can be found on the PNT Advisory Board website.
According to the document, the board prepared the white paper to support recommendation number PNT27-04-ECAS, which is to develop and implement a GPS HARS delivered to users via the Internet. The HARS concept was approved at the PNTAB-27 meeting (Nov. 16-17, 2022) and formally submitted to the National Space-Based PNT EXCOM co-chairs via Memorandum on Jan. 27, 2023.
Recommendation PNT27-04. (Photo: Presentation by John W. Betz, PhD Member, National Space‐Based PNT Advisory Board on May 29, 2024)
The November and December Advisory Board meetings are recorded, and individuals can listen to the entire meeting. The Board’s website provides links to the meeting agenda and presentations. Pe’eri’s presentation on HARS started at 10:30 am on Dec. 4 (2:04 on the recording).
During the meeting, the PNT Advisory Board officially stated that it supports the HARS Concept described by NOAA. Of course, the Board also stated that it has no money, but the Board’s stamp of approval of the concept is very important. Now, it is up to NOAA’s NGS to work with other federal agencies, such as NASA’s Jet Propulsion Laboratory (JPL), to work out the details and resources. By leveraging NASA’s real-time Global Differential GPS (GDGPS) System infrastructure and NOAA’s service delivery platforms, a high-accuracy, resilient service that ensures delivery of precise, reliable and secure GNSS corrections for a wide range of scientific and commercial applications can be built for the nation.
So, what exactly is the GPS High Accuracy and Robustness Service (HARS)? The following is a statement from a Jan. 27, 2023, PNT Memo:
“Implementing a GPS High Accuracy and Robustness Service: To augment GPS and overcome some inherent limitations of space-based PNT, the USG should provide a service comparable to the European Union’s Galileo HAS that provides signal corrections than enable better than one-meter level accuracy, as well as cryptographically-protected satellite navigation message data bits for integrity processing. The U.S. should develop and implement GPS HARS, based on the capabilities developed by the JPL for GDGPS, to be made available to users over the Internet.”
The white paper describes the problem and the solution as the following:
“The problem: GPS is falling behind other Global Navigation Satellite Systems (GNSSs) such as Europe’s Galileo and China’s Beidou. GPS has adopted an approach of allowing augmentation by third-party systems (such as Assisted-GNSS in mobile phones, WAAS for aviation accuracy and integrity, and commercial RTK for precision users), rather than providing specialized advanced services itself. Also, the data message modulated on the GPS signals is fragile. Environmental effects or malicious actions can prevent a receiver from reading the information or manipulate what is read, limiting the robustness of the GPS signals. Currently, GPS is the primary system in almost all GNSS chips, even chips made in Europe or Asia. That is: chips are designed to acquire GPS signals first, then signals from other systems. But Galileo and BeiDou are deploying high accuracy services that provide sub-meter position accuracy, enhancing satnav use in many civil applications. The absence of any plan for GPS to offer a similarly high accuracy service could cause GNSS chips to begin using Galileo or BeiDou, rather than GPS, as the primary system. A switch away from GPS as the primary PNT system is a problem for the US Government because it will lose its strategic advantage. Existing commercial chips are used in many strategically important US assets, such as airlines, ships, and organizations that support the US military. Once these chips change their architecture to Galileo-first or BeiDou-first, these strategic use cases depend on these services. It is one step in the direction of not having a GNSS system at all and borrowing the system of another power, exactly the situation that Europe and China were in before they built their own systems. GPS would no longer be the “pre-eminent space-based PNT service” called for in Space Policy Directive 7.”
“The Solution:A high accuracy and robustness service (HARS) provides information to user receivers, reducing errors and enhancing the ability to operate in challenging conditions. The PNT Advisory Board has identified a solution that the U.S. government can provide a HARS without adding cost and complexity to GPS itself; instead, the needed information from government or government-sponsored organizations can be obtained and provided over the Internet to properly equipped receivers. The result would be a world-class HARS at a small fraction of the cost or time, compared to implementing it on new GPS satellites. The HARS would provide cryptographically-protected robust (resistant to jamming and spoofing) GPS for critical infrastructure and would enable new applications (such as lane-dependent route guidance in automobile navigation and emergency vehicle guidance, GPS-only precision positioning of drones) that extend the societal benefits of GPS. HARS would be secure and less sensitive to radio noise and disruptions, including spoofing.”
The following are a few slides from Pe’eri’s presentation highlighting the need for HARS. He mentioned that there are six regional high accuracy systems and one global service that is already operational or in development.
Six regional HAS and one global HAS are operational or in development at this time. (Photo: NOAA/NGS)
NOAA’s presentation by Pe’eri was in response to a request by the Advisory Board. The Board was interested in learning more about the funding and operating a public service that can provide robust real-time GPS corrections. Summarized in three bullets:
High-Accuracy: Real-time corrections to GPS orbit parameters and clocks to enable more accurate positioning solutions.
Robustness: Nav Data (ephemeris) can be cryptographically signed and delivered on the same channel.
Service: Delivered over the Internet and is free to all users.
The HARS could be accomplished by employing the expertise, knowledge, and capabilities of NASA’s JPL and NOAA’s NGS.
NOAA has the authority to provide real-time operational services and regularly collaborates with other federal and state agencies and local communities. NGS manages and distributes the NOAA CORS Network (Foundation and Cooperative CORS). NASA JPL collects GNSS data and generates products with high accuracy.
NGS expertise and knowledge. (Photo: NGS/NOAA)
NASA’s GDGPS is a complete, highly accurate and extremely robust real-time GNSS monitoring and augmentation system. The CCDIS website states, “Employing a large ground network of real-time reference receivers, innovative network architecture, and real-time data processing software, the GDGPS System provides sub-decimeter (<10 cm) positioning accuracy and sub-nanosecond time transfer accuracy anywhere in the world, on the ground, in the air, and in space, independent of local infrastructure.”
JPL expertise and knowledge. (Photo: NASA)
By leveraging NASA’s real-time GDGPS System infrastructure and NOAA’s service delivery platforms, NGS and JPL can build a high-accuracy, resilient service that ensures delivery of precise, reliable and secure GNSS corrections for a wide range of scientific and commercial applications.
Pe’eri’s presentation highlighted HARS benefits to the daily operations of users of geospatial data.
HARS benefits for users. (Photo: NOAA/NGS)
The HARS concept is extremely important to the U.S. GPS user community, where the number of users is increasing every day. A 2019 Department of Commerce (NIST) study, “Economic Benefits of the Global Positioning System (GPS),” highlighted the economic damages a GPS outage would have on the agricultural industry.
The 2019 NIST study, “Economic Benefits of the Global Positioning System (GPS),” determined that $1.4 trillion in U.S. economic benefits from GPS. The study stated that a 30-day widespread outage could erode less than $1 billion in economic value per day. The study also highlighted the impact a GPS outage would have on Agriculture, stating that during planting season, economic damages in the agriculture sector could increase 30-day losses to $15 billion due to lower yields.
Table ES-1 and figure ES-1 from the 2019 report highlight the economic benefits of GPS for private sector use.
Table ES-1: Summary of economic benefits of GPS for private-sector use, 1984 to 2017. (Photo: NIST) Figure ES-1: Time series of GPS’s economic benefits for the private sector. (Photo: NIST)
I would encourage others to look at the PNT website, especially the Advisory Board website, to obtain information about space-based PNT. Other recommendations and letters from the Advisory Board to the Executive Committee (EXCOM) can be found on the PNT and Advisory Board websites. The webpage provides the Advisory Board’s recommendations on ways to improve GPS and national GPS management. The recommendations are published in the interest of public transparency.
In response to the recent wildfires in Southern California, Topcon Positioning Systems is now offering free access to its GNSS correction services network for emergency recovery efforts. The company is offering a 90-day subscription to its Topnet Live service, which delivers precise positioning data crucial for assessing damaged infrastructure, surveying, utility mapping and operating construction equipment.
The technology is being made available at no cost within affected areas to support first responders, public works teams, and other professionals involved in damage assessment, infrastructure repairs, and rebuilding initiatives. The service is compatible with any brand of receiver capable of using RTCM format NTRIP corrections.
“We want to help the efforts that are ongoing and aid in the future reconstruction of the damaged communities from these wildfires,” said Jason Killpack, director of Topcon emerging business development. “The 90-day emergency subscription service is free to anybody that needs them to get their essential job done.”
Individuals or organizations seeking to activate this service can contact participating Topcon distributors in California. Contact information is available on the company’s website for those interested in utilizing the emergency assistance.
Nearly three quarters of Earth’s surface is covered by water, yet only about a quarter of that surface has been mapped in detail using modern high-resolution technology.
Marine experts worldwide work together to chart the ocean floor, ensuring the safety of ports, harbors and navigable routes. This effort is crucial for global trade, as more than 90% of goods are transported by ships. Ocean floor surveying also supports the installation of offshore infrastructure such as fiber optic cables, pipelines, drilling platforms and wind turbines.
The increasing population in coastal regions and rising sea levels due to climate change have heightened the importance of observing coastal transformations, erosion and other marine alterations. These factors are essential for understanding and protecting coastal ecosystems.
Mapping techniques
In deep waters, massive multi-beam echo sounders (MBES) operating at very low frequencies collect depth data. As water depth decreases, smaller devices with higher frequencies and resolution must be used. However, near the shore, these devices become less efficient due to the slope of the shelf interfering with sound signals.
In near-shore scenarios, collecting depth data is best done using airborne lidar sensors, which offer several advantages over sensors on surface vessels. One advantage of airborne sensors is that they can simultaneously map both the seafloor and the adjacent topography to offer seamless land-water transition data. This capability is particularly valuable in dynamic coastal environments where rapid coverage of large areas is essential.
Bathymetric lidar is specifically designed for mapping shallow coastal waters, typically effective up to depths of 50 m. It can provide high-resolution data, often achieving sub-meter positional accuracy, which is crucial for detailed coastal mapping. By combining MBES for deeper waters with lidar for near-shore areas, researchers and surveyors can create comprehensive and accurate maps of the entire coastal zone. This method offers an in-depth understanding of underwater topography, aiding various applications in marine science, coastal management and navigation.
The waters of the Cayman Islands are abundant in marine life, featuring coral reefs, seagrass beds and a variety of fish species. A high-resolution map of the seafloor is essential to begin exploring, identifying, characterizing, exploiting, conserving and managing ocean resources. Saildrone has begun a mission to map 29,300 square nautical miles (100,490 sq km) of the Cayman Islands’ Exclusive Economic Zone (EEZ). This mission uses autonomous technology to survey 80% of this EEZ.
The Cayman Islands EEZ, extending up to 200 nautical miles from shore, encompasses an area nearly half the size of Florida — and 380 times greater than the island itself. The mission will provide detailed and precise bathymetric data for this area, contributing to a comprehensive understanding of the seafloor topography in the region. The data collected seeks to enhance maritime navigation and support scientific research, environmental conservation efforts and marine resource management in the Cayman Islands.
“Our waters hold such great value to us for a myriad of reasons, ranging from recreational to economic. Conducting this assessment will allow our government to make data-driven decisions that will strengthen our policies and legislation as it relates to our maritime infrastructure,” said Juliana O’Connor-Connolly, premier and minister for District Administration and Lands.
The Saildrone Surveyor USV is a purpose-built platform for autonomous deep-water ocean mapping. (Photo: Saildrone)
The mission is philanthropically funded by the London and Amsterdam Trust Company Limited, a Cayman-based organization. Saildrone is tasked with collecting the raw bathymetry data, which will be provided to the UK Hydrographic Office to process and update the Cayman Islands’ nautical charts. The data will belong to the government of the Cayman Islands.
Autonomous seafloor exploration
The mission is being conducted using a 20-m Saildrone Surveyor uncrewed surface vehicle (USV) equipped with MBES and metocean sensors for ocean mapping and ecosystem monitoring, as well as radar, cameras and advanced machine learning. Metocean stands for meteorology and physical oceanography. Globally, only 26% of the ocean has been mapped, a result of the lack of survey ship capacity. While a survey ship takes years to build, Saildrone can produce one Surveyor in as little as six weeks.
This nautical chart shows the Cayman priority mapping areas. The yellow oval indicates the vessel’s location as of Dec. 9, 2024. (Photo: Saildrone)
Saildrone USVs have demonstrated a reduction of more than 97% in operational carbon emissions when compared to survey ships to accomplish the same task. Additionally, they lower the risk to personnel. This information is highlighted in Saildrone’s Carbon Impact Report, which provides a comprehensive evaluation of the carbon emissions associated with maritime data collection and the emissions mitigated by using Saildrone’s USVs.
Saildrone’s ocean mapping solutions support storm surge modeling efforts and emergency response, as well as coastal resiliency and hazard studies, resource management, restoration projects, habitat mapping and infrastructure for renewable energy generation. USVs equipped with deep ocean mapping sonars now serve as a reliable option for data collection in large areas such as EEZs.
Bathymetry is crucial to understanding Earth’s aquatic environments. Its importance has evolved significantly since the early days of navigation, when mariners relied on lead lines and poles to gauge water depths. The field of bathymetry continues to advance with emerging trends that enhance data collection capabilities. Autonomous platforms such as USVs and autonomous underwater vehicles are increasingly utilized for bathymetric surveys, allowing for more extensive and detailed mapping. Additionally, as the industry grapples with challenges such as workforce shortages and the need for more efficient data collection methods, autonomous systems are proving to be a valuable solution.
Trimble’s Applanix POSPac MMS, an advanced GNSS-inertial post-processing software, seamlessly integrates with the Applanix POS MV and multibeam or sonar sensors to deliver high-accuracy results. (Photo: Trimble)
“Autonomous and uncrewed platforms have become a real force multiplier, and the trend continues,” said Peter Stewart, director of marine products at Trimble Applanix. “Companies such as XOcean and Saildrone are showing what is possible, leveraging cloud processing and enabling data collection in remote areas while maintaining a work-life balance for their staff. Since finding qualified engineers and surveyors to fill these roles offshore is an industry-wide concern, more flexible working conditions are needed to hire and retain talent.”
Another emerging trend is the development of sensors capable of penetrating murky waters, which can significantly enhance surveyors’ ability to gather data in challenging environments. Advanced sonar systems, innovative light-and-sound combinations and newly developed sensors allow research teams to collect detailed data. Post-processing technology for bathymetry has also significantly advanced, making data acquisition, processing and presentation more efficient and accessible. This allows researchers to map and study underwater terrains that were previously inaccessible or poorly understood.
Typical marine vessel data processed in POSPac MMS PP-RTX mode. (Photo: Trimble)
“Ease of use and installation are key trends toward ensuring valuable hydrographic data can be acquired, processed and presented efficiently,” Stewart said. Trimble works with users and third parties to offer an optimal workflow, making technology and the data it creates more accessible and operations more efficient, he added.
The IN-Fusion+ PP-RTX2 processing mode in Trimble’s POSPac MMS software is designed to improve post-processed GNSS-inertial trajectory generation. This mode uses Trimble’s CenterPoint RTX technology to deliver centimeter-level positioning accuracy without the need for local base stations. Stewart shared how this technology can be particularly useful when surveying around offshore windfarms, where shore-based RTK infrastructure is often too distant to be useable.
Topcon Positioning Systems has expanded its Topnet Live reference station network by adding 200 new geodetic stations across the United States. This expansion enhances the availability of centimeter-level accuracy for industries requiring precise positioning, such as engineering, surveying, construction and agriculture.
The upgraded network provides advanced network corrections that optimize operational workflows in various sectors. The enhanced infrastructure supports emerging technologies such as automated turf management, precision line marking, imaging systems and UAV operations for mapping and delivery.
This expansion builds upon previous efforts throughout 2024, resulting in a 30% increase in Topnet Live’s total coverage in the United States. The network now offers comprehensive, network-modeled solutions that cater to a wide range of professional requirements across multiple market segments.
The Topnet Live network utilizes Networked Transport of RTCM via Internet Protocol (NTRIP) to stream GNSS corrections data via the Internet for RTK positioning. This technology allows for centimeter-level accuracy by mitigating errors from factors such as ionospheric disturbances, satellite clock deviations and orbit inaccuracies.
Eos Positioning Systems (Eos) has become a member of the Municipal Information Systems Association (MISA) Canada’s National Partner Program (NPP). This collaboration aims to enhance the capabilities of Canadian municipalities in utilizing GNSS technology for improved mapping and asset management.
The partnership between Eos and MISA Canada facilitates the digital transformation of Canadian cities and towns by bringing together municipal leaders and technology innovators. Eos specializes in providing high-accuracy GNSS technology to local governments, enabling them to maintain critical infrastructure and public services more effectively.
Eos manufactures GNSS receivers in Canada that offer submeter to centimeter-level accuracy for GIS and mapping applications. These tools are particularly useful for utility and infrastructure mapping, public works asset management, environmental monitoring and planning and emergency response coordination.
The GNSS receivers from Eos are designed to integrate with existing GIS software and mobile devices, allowing field teams to efficiently collect, update, and manage spatial data with high precision. As part of MISA’s NPP, Eos will provide members with access to specialized solutions, training resources, and ongoing technical support to maximize the benefits of GNSS technology in municipal operations.
All construction work begins with surveying to map the site and generally ends with surveying to document what was done on it — called “as built.” Therefore, surveyors are the first to arrive at a construction site, well before the first heavy machinery, and the last ones to leave, well after the construction crews have left with their equipment. During construction, surveyors get to work any time there are changes in the plans.
Surveyors are not the only ones to use survey-grade GNSS receivers on a construction site, though. GNSS for machine control is increasingly common on excavators, graders, dozers and other heavy machinery. It enables operators to achieve accurate earthmoving and grading operations with minimal manual intervention, significantly improving efficiency and reducing rework by providing real-time positioning data based on 3D design models. Additionally, a dedicated display in the cab allows operators to see a visual representation of the machine’s position relative to the design model and to make adjustments in real-time.
This month’s cover story features case studies from four companies:
CHC Navigation (CHCNAV) on grading for an airport construction project in Shanghai, China.
ComNav Technology on a river flow monitoring system to mitigate the effects of flooding in Japan.
Nearmap on solving the stormwater challenges of a small town in Michigan.
Frontier Precision on the repair of a canal in Montana in very challenging conditions.
Construction of a building cannot begin until the ground is level and matches the design so that it can bear the weight of the planned structure. At times, part of the ground needs to be sloped to ensure proper drainage or to meet the aesthetic needs of the project. However, the ground at a construction site is often uneven and/or sloped the wrong way. Therefore, a critical phase of any AEC project is grading, which is a specialized phase of the construction process that uses machinery such as graders, bulldozers, excavators, and dump trucks to move and shape large amounts of earth.
Traditionally, grading involved the use of string lines and optical levels, which are still valuable for smaller projects. These tools provide a visual reference for achieving the desired slope and allow for manual adjustments as needed. Modern construction practices rely on laser levels — which provide accurate measurements, ensuring a consistent slope — and, increasingly, on GNSS receivers, which aid in precise grading, especially in large-scale projects.
In a recent project to build an apron — a paved area where aircraft are parked, loaded, unloaded, refueled and boarded, also known as the ramp, flight line or tarmac — as part of the expansion of Shanghai Pudong International Airport, the construction company adopted CHCNAV’s i93 GNSS receiver solution. The project, by a large state-owned construction company, began at the end of July 2024 and is expected to take two years to complete. By directly loading the designed triangulated terrain model (TTM) for surface stakeout, the project managers were able to visualize the cut-and-fill values at any location in real time. This approach doubled the stakeout efficiency and significantly improved the quality of site grading.
Project challenges and solution
The airport project covered approximately 360,000 m², demanding high-precision grading. Traditional surveying methods could only verify cut-and-fill heights at grid nodes, failing to effectively cover areas between these nodes. This limitation increased the risk of uneven construction and restricted the comprehensiveness of elevation data. Additionally, the traditional stakeout process was cumbersome and inefficient, requiring point selection before stakeout. To overcome these challenges, the construction team needed a surveying solution that could significantly enhance stakeout efficiency while improving grading precision and construction outcomes.
The construction team used the CHCNAV i93 GNSS receiver and LandStar field survey APP. By using the surface stakeout function for site grading, it was able to load the TTM generated from design data directly into the LandStar software, simplifying the grading process. The software enabled surveyors to obtain cut-and-fill values at any location in real time, thereby eliminating reliance on grid nodes and enabling dynamic verification across the entire site for higher grading precision. Lastly, the solution doubled the stakeout efficiency by reducing the steps of selecting feature points before stakeout.
Using CHCNAV’s Satellite Wide Area System (SWAS) corrections network, a global system that offers users fast and precise centimeter-level positioning services, the surveyor was able to achieve an elevation accuracy of -3 cm ~ +2 cm. SWAS covers most of the inhabited areas in China and is expanding its network globally. CHCNav’s satellite Precise Point Positioning service is being developed and tested; it will become part of the SWAS service in the future. The surveyor guides the site grading by comparing the difference between the elevation in the design plans and the measured elevation. Therefore, when the site grading is complete, it should match the design plans.
Conclusions
“The project involves large areas of earth excavation and levelling,” said Yang, the chief of the survey team. “In the past, we had to stake out all the points of the grid after getting the design drawings, and then calculate the elevation difference of each point. If there were some special points, we also had to calculate their positions in the grid. Now, in LandStar 8, we can directly convert the grid drawing into a TTM file and stakeout, which makes it easy for us to set the elevation difference at any point without the limitation of the grid. This increased efficiency accelerated the progress of the project and reduced our workload.”
The adoption of CHCNAV’s surveying and construction solution significantly accelerated the project’s site grading work. This task, which traditionally would have taken about one month to complete, was fully accomplished in just half a month. During the project acceptance phase, the results met all design requirements and passed inspection smoothly. The construction unit reported that the CHCNAV i93 GNSS receiver and LandStar field survey APP greatly enhanced the efficiency and accuracy of the site grading portion of the construction project.
It is essential to take effective measures to mitigate the effects of natural disasters — such as earthquakes or hurricanes — and to prevent them when possible, such as sometimes with floods. This involves multiple aspects, including the development and rehearsal of emergency plans, the construction and reinforcement of infrastructure, and the monitoring of environmental changes. By identifying potential disaster risks and taking preventive actions, the damage caused by these disasters can be significantly reduced and the resilience of communities and cities can be enhanced, thus better preparing for future catastrophes.
How can these disaster mitigation and prevention measures be specifically implemented? First, by creating detailed emergency plans and conducting regular drills, which ensures a quick and effective response during critical situations. Second, by reinforcing critical infrastructure, such as protective embankments and resilient systems, which strengthens the overall preparedness of both urban and rural areas. Moreover, monitoring environmental changes plays a pivotal role in prevention efforts. Real-time observation systems, including advanced sensors and data integration platforms, enable the early detection of potential risks. This facilitates timely preventive actions, minimizing losses with optimal efficiency and resource utilization.
Mars Pro Laser RTK was used to precisely measure the positions of monitoring cameras in the Abukuma River basin.(Photo: Geosurf Corporation)
Monitoring systems
A key aspect of flood defense and disaster prevention is the establishment of monitoring systems and the enhancement of safety measures. In the Abukuma River basin, which flows through Fukushima and Miyagi prefectures in Japan, a flood monitoring system has been built that combines data from water level meters with real-time information on changes in water levels due to natural events such as typhoons. This provides residents with immediate visual updates to help them respond effectively.
ComNav Technology’s Mars Pro Laser RTK has played an important role in this flood prevention and disaster monitoring project. By using the device, which integrates advanced GNSS, IMU, and laser technologies, a team from Geosurf Corporation was able to accurately determine the locations for installing surveillance cameras, ensuring real-time monitoring of water flow conditions, and providing early warnings for natural disasters such as floods. The locations of these cameras typically include areas with a high risk of riverbank collapse, water level observation stations, and other critical spots that require close monitoring.
In the past, this task would have required using a total station. However, using Mars Pro’s very precise green laser, the crews were able to measure the locations of offset points that did not have a clear view of the sky, which is required to receive GNSS signals.
Centimeter-level accuracy
The green laser, which is visible in daylight, enabled the crews to achieve centimeter-level accuracy at any point within a range of 10 meters. They were also able to use its 120-degree tilt compensation feature to drive the stakes efficiently closer to the target point without worrying about leveling. During the RTK positioning process, the team used reliable correction information sources and precise post-processing analysis methods, ensuring that the measurement point consistency was maintained within 2 cm to 3 cm, thus ensuring high accuracy and consistency of the measurement results.
Positioning surveillance cameras in the Abukuma River basin required measuring not only their placements but also the reference points within their coverage areas. Beyond its convenience and reliability, the Mars Pro Laser RTK and its paired software, Survey Master, simplified the survey workflow by using wizard functions. Specifically, the procedure is to follow the instructions of the surveillance camera monitor to move onto the centerline and use the program’s Angle Offset Calculator to calculate the coordinates of a reference point at ±90 degrees to the line segment. Survey Master’s simple survey calculation tool eliminates the need to launch a CAD program in the field, making the staking more efficient.
For the correction information in RTK positioning, Geosurf Corporation used ichimil, a high-precision positioning service provided by Softbank. Geosurf also acquired raw data for post-processing at several locations at the same time and analyzed the measurement points using coordinate results from Japan’s Geospatial Information Authority.
The surveyor used Mars Pro Laser RTK and Survey Master software to measure the reference points within coverage areas of surveillance cameras. (Photo: Geosurf Corporation)
Conclusions
The monitoring system combines water level data collected from devices such as water level meters with changes in water levels caused by natural events such as typhoons, providing real-time visual information to residents. This allows them to stay informed about current water levels, identify potential flood risks early, and take appropriate preventive measures, effectively reducing disaster risks and safeguarding lives and property. More than 100 surveillance cameras have been installed so far in the Abukuma River and its associated watershed.
Through this project, Mars Pro Laser RTK not only enhanced emergency response capabilities but also showcased the versatility of laser RTK technology in disaster prevention and mitigation applications. Climate change is increasing the damage caused by typhoons and torrential rains worldwide. As a result, the demand for such monitoring systems is expected to grow. ComNav Technology plans to further improve user experience by integrating laser technology with additional sensors and developing more innovative tools to address future disaster prevention needs.
While surveyors are typically the first to begin working on a construction site, but they do not start completely from scratch. As a basemap for their measurements, they often use satellite and aerial imagery, the latter collected by planes and UAVs — the same imagery used in geographic information systems (GIS) by governments at every level and private companies to plan, build, and manage buildings and infrastructure. These data include high-resolution orthimages, which are taken pointing straight down at the ground and adjusted to have a constant scale of distance across them; oblique images, which can offer an alternative view of the landscape and structures where height is important; 3D datasets, including digital elevation models and models of buildings, collected using lidar; and AI-derived spatial information.
Additionally, historical imagery datasets document the evolution of land use over time and make it possible to compare conditions before and after natural disasters, such as floods and earthquakes, to expedite emergency response and reconstruction planning.
An aerial image of southfield, Michigan, from Nearmap’s natural pervious surface AI data layer. (Photo: Nearmap)
Stormwater utilities project
With a diverse population, more than 10,000 businesses, and a commitment to urban development, the City of Southfield, Michigan is known for its robust economy, thriving commercial centers, modern urban living and innovation. When it needed help to effectively manage its stormwater utilities, the city hired OHM Advisors. Founded in 1962 and with a multidisciplinary team of more than 700 experts, the firm provides consulting in the areas of architecture, engineering, planning, urban design, landscape architecture, surveying, and construction engineering. In turn, for this project, OHM Advisors used location intelligence from Nearmap, an aerial imagery company founded in 2007 that captures urban areas across the United States, Canada, Australia and New Zealand.
Initially, the city planned to have access to the Nearmap imagery for only a year, for use in its stormwater utilities project. However, once it realized how useful it would be across city departments and projects, it decided to continue buying it for the long term.
Aerial imagery
The City of Southfield is currently in the planning stages of considering a new initiative to assess stormwater fees based on the number of impervious surfaces — such as asphalt and concrete — which do not allow water to penetrate the ground, thereby contributing to increased runoff and straining municipal systems. However, the city is challenged by its limited budget for maintaining, let alone upgrading, its stormwater infrastructure. Additionally, the aerial imagery it had was old and one-time flyovers of the small city to update the imagery would have been prohibitively expensive, costing up $100,000.
By purchasing high-resolution aerial imagery (captured up to three times a year), geospatial data, and AI feature layers from Nearmap, as recommended by OHM, the city was able to efficiently map impervious surfaces and readily view, identify, and verify stormwater utilities at scale. This enabled the city to develop a highly accurate and equitable system for assessing fees based on near-real-time data. It also improved the precision and efficiency of its urban planning; enabled city planners to complete tasks remotely, spending less time in the field; and updated the imagery in its GIS.
Business impact
Using current aerial imagery, geospatial data, and AI data, Nearmap and OHM identified every impervious surface in the city, enabling Southfield to:
Accurately assess stormwater fees. Analysis of Nearmap imagery and AI data allowed OHM to tie impervious surface area to stormwater fees and establish a precise, data-backed fee structure that bolsters the city’s infrastructure funding.
Reduce costs. Nearmap offered a cost-effective alternative to traditional data collection, drastically reducing the city’s expenditure without sacrificing data quality.
Enhance urban planning. Access to Nearmap facilitated remote decision-making, allowing Southfield to optimize its urban planning.
Maintain consistent data. OHM and Nearmap led to the resolution of Southfield’s data discrepancies, ensuring reliable insights for future planning.
Conclusions
“Using the high-quality Nearmap AI data allowed the OHM Advisors’ GIS team to efficiently and effectively map out the impervious surfaces for the city,” said Mike Cousins, GISP, practice leader for GIS at OHM Advisors. “Having high-resolution and very recent imagery to pair with the impervious surface data helped with the analysis portion of the project at hand.” The collaboration between OHM Advisors and Nearmap marked a significant change in Southfield’s approach to stormwater management, illustrating the potential of advanced technology to improve urban governance.
The St. Mary Canal and siphon were completed in 1915 as part of the Milk River Project in North-Central Montana. The canal has delivered water to 110,000 acres of agricultural land in eastern Montana for 109 years. In June 2024, the siphon had a catastrophic blowout when both 90-inch siphon pipes failed, releasing 600 ft³ of water per second for more than 24 hours.
The stakeholders involved quickly went to work on a solution to replace the two siphon pipes. By mid-July, NW Construction, Inc. was brought on site to begin demoing and replacing the siphon. The company uses Frontier Precision as its supplier for all its surveying equipment. Utilizing a mix of GPS machine control, geospatial survey equipment, aerial drone surveys and CAD software, NW Construction will work through the blistering Northern Montana winter to restore the siphon in time for the 2025 irrigation season.
The harsh environment and speed of the project pose tough conditions for surveying. Winds regularly reach 60 mph with gusts up to 80 mph and temperatures go well below freezing for most of the winter. The surveyors on this project will have to overcome the challenges that come with this weather and the remoteness of the project.
The project has about six excavators, including two with tilt rotators, and four dozers, all equipped with GNSS machine control. “Everything we do is completely modeled for those guys through civil 3D and Trimble Business Center,” said Kenny Neskorik, project engineer for Northwest Construction. The GNSS receivers on the earth movers are running RTK as rovers and there is a single base receiver. “When we do any sort of concrete work for this project, we will also set up a robotic total station,” he said.
Additionally, the project uses a DJI Mavic UAV to collect aerial photogrammetry of such things as finished excavation and original ground stockpiles.
Requirements
The requirements for this project are atypical, Neskorik explained, due to its emergency nature. “The design and the construction are going on at the same time through two different entities,” he said. “My company is not the engineering firm stamping the plans. We’re the ones doing the work. I
could almost describe it as a design build, in which the contractor and the engineer meet in the middle to get the best product in the fastest way.”
The project’s biggest requirement is to get water back to the eastern part of the state by summer, when it will be needed to irrigate crops. “To do that,” Neskorik said, “we had to set control.” Because the project is only a few miles from the Canadian border, however, the power of radio broadcasts is restricted to only 2 Watts instead of the usual 35 Watts on RTK radios. “That really hurts your range to talk to your base,” he said. This required setting up several relay repeaters, especially since there’s almost no cell phone service in Montana
Challenges
An additional challenge is the solar cycle, which is nearing its peak. “We have noticed lots of Northern Lights, lots of auroras,” said Neskorik, “but we haven’t seen too many disruptions yet.”
Finally, the biggest challenge is the weather. “We’ve already had probably cumulatively two feet of snowfall,” said Neskorik. “Thankfully, some of that has already melted, but this area is one of the colder parts in the United States.” Browning, he pointed out, is just 30 minutes south of us, holds the world record for fastest temperature change in 24 hours — from 56 degrees Fahrenheit to negative 46 degrees. It’s not uncommon to see negative 50 degrees. “At that temperature, your batteries die really fast, you cannot use touch screens, and you have to drill to set stakes in the frozen ground is frozen. We’ve already experienced winds at nearly 80 miles an hour and that is pretty much how it goes for the entire winter. So, as you can imagine, it’s not an easy task flying a drone around here.”
Accuracy
“Our company standard for any excavator or dozer is an accuracy of one tenth of a foot,” said Neskorik. “We want our GPS rovers to have a vertical tolerance below 5/100s of a foot. Realistically, you’re probably getting a 1/10 of a foot. You cannot have any major fluctuations in the dirt because the pipe sits directly on it.” This all must happen in real time because there is no post-processing. “Everything is modeled and the machines are running on a model. We’re checking their grades as they’re doing the work.”
Bad Elf and GEODNET have introduced a five-year RTK service for Bad Elf GPS receivers, designed to provide high-accuracy GPS positioning for professionals in surveying, agriculture, construction and geospatial data collection. The service offers real-time centimeter-level accuracy, designed to improve the precision of GPS data for users.
Benefits of the RTK service for Bad Elf GPS receivers:
Enhanced accuracy: Achieve centimeter-level accuracy in real-time to improve the precision of GPS data.
Seamless integration: The RTK service is designed to work with all Bad Elf GPS receivers, with one-click activation after setup.
Reliability: GEODNET’s robust network offers continuous and reliable service, even in challenging environments.
The RTK service is priced at $999 for five years, offering a long-term, cost-effective solution for professionals. It is compatible with all Bad Elf GPS receivers, including the Flex and Flex Mini models, and can be activated with a one-click setup process.
GEODNET’s network underpins the service, aiming to provide continuous and reliable performance across various environments. The company guarantees the availability of an RTK reference station within 40 km for subscribers in the United States and Europe, with potential expansion to other countries based on demand.
Geospatial professionals using iOS or Android devices can access the RTK corrections in supported regions, enabling them to perform complex location-based tasks with increased confidence in their GPS data accuracy. This service represents a significant development in the field of high-precision GPS technology, offering an integrated solution for professionals requiring accurate positioning data across multiple industries.
Notre Dame de Paris, the French capital’s cathedral, has reopened its doors five years after a devastating fire, showcasing its restored interior after extensive rebuilding work. The restoration, costing approximately €700 million ($737 million), was financed entirely by donations from around the world.
On April 15, 2019, Notre Dame tragically went up in flames, with the spire collapsing and the roof being destroyed. The following years were dedicated to rebuilding the cathedral, including the reconstruction of the spire and the restoration of stained glass and woodwork.
A crucial element in the restoration process was the point cloud data collected by Professor Andrew Tallon, an architectural historian from Vassar College, in 2010. Tallon’s project, which aimed to fully understand the Gothic structure and identify structural anomalies, involved creating a precise 3D model of Notre Dame using a Leica Geosystems terrestrial laser scanner.
This cloud of 1 billion points — with a TruView released by Leica Geosystems available to view here — proved to be indispensable for the digital recreation of the cathedral’s interior and exterior. Tallon’s laser scans were the only truly accurate as-built measurements of Notre Dame, translating point clouds into detailed representations of its buttresses, ribbed vaults, stained glass, ornate carvings and other architectural details.
Tallon, who died of cancer in November 2018, pioneered the use of laser technology to create a digital model of Notre Dame. Members of the restoration team and architectural historian Lindsay S. Cook — assistant teaching professor of architectural history at Pennsylvania State University, and a protégé of Tallon’s — said his work was critical to the cathedral’s rebuilding and refurbishing.
Tallon took some self-portraits as he mapped the cathedral. (Photo courtesy of the family of Andrew Tallon / Vassar College)
The value of point cloud data
While modern restoration efforts cannot fully replicate the artistry of centuries past, Tallon’s scans have been instrumental in reconstructing the Gothic cathedral, allowing architects to come remarkably close. Tallon’s groundbreaking work remained a vital resource for restoring the iconic cathedral to this day.
His meticulous 3D scans of Notre Dame provided architects with information crucial for the cathedral’s reconstruction, including:
Precise 3D models: Tallon’s precise 3D model of Notre Dame included intricate details of the cathedral’s architecture, such as flying buttresses, rib vaults, stained glass windows and ornate carvings. This level of detail was unmatched by any historical drawings or records, which often lacked precision.
Dimensional and formal reconstruction: Pascal Prunet, one of the architects tasked with rebuilding the cathedral, said in an interview with Lindsay S. Cook that the point cloud data provided an “exact trace” of the cathedral’s state at the time of scanning, allowing him and his team to reconstruct elements — such as the vaults — “without hesitation” regarding dimensions or forms. This was essential for accurately rebuilding complex structures such as flying buttresses and rib vaults.
Structural analysis: The scans revealed structural details that were previously unknown, aiding in understanding how the cathedral was originally constructed and how it changed over time. This information was vital for designing custom supports and ensuring structural stability during reconstruction.
Integration with modern technology: The point cloud data was integrated into Building Information Modeling (BIM) processes, which allowed architects to create a digital twin of Notre Dame.
Restoration guidance: The scans provided a highly detailed record of Notre Dame’s pre-fire condition, which helped restoration professionals select appropriate techniques for stabilizing and rebuilding various parts of the cathedral.
Tallon’s laser scans provided the only accurate as-built measurments of Notre Dame de Paris, capturing detailed representations of its architectural features. (Photo: Andrew Tallon (Vassar College / Columbia University))
Why precision matters
On Oct. 25, 2023, Philippe Villeneuve, architect in chief of historical monuments in charge of Notre Dame, and Pascal Prunet, a fellow restoration architect, delivered a Claflin Lecture at Vassar College in New York. They discussed their efforts to shore up, conserve and restore the cathedral since the devastating fire.
3D digital renderings were obtained from Tallon’s laser scans of Notre Dame Cathedral in Paris. (Photo: Andrew Tallon (Vassar College / Columbia University))
The two architects highlighted the crucial role Tallon’s laser scan of the cathedral played in their restoration process. They shared how this detailed digital model provided them with precise measurements and structural information, enabling Notre Dame to, in essence, “guide its own restoration.” By relying on this accurate data, the team could ensure its work remained faithful to the iconic cathedral’s original design and construction.
When speaking with Cook, Prunet shared, “At Notre Dame, we are doing an enormous amount of work, but we are not doing creative work; we are putting things back together again.” Villeneuve added, “What we’re doing isn’t very personal.” Tallon’s laser scan has enabled the architects to allow Notre Dame to “speak for itself,” according to Villeneuve.
Tallon had sent a copy of his point cloud to Villeneuve’s predecessor, Benjamin Mouton, before Mouton retired in 2013. After the 2019 fire, Marie Tallon saw that the architects had access to her late husband’s work. During their 2023 lecture and in a follow-up interview, Villeneuve and Prunet said Tallon’s scan — which Prunet called an “exact trace” of the state of the building at the time it was scanned — had been used in numerous ways since the fire.
For example, it aided the design of the wooden centering custom-made to cradle each unique flying buttress and rib vault and to rebuild the damaged vaults and the sole transverse arch destroyed when the tip of the spire separated from its base and fell westward, becoming a projectile that crashed into the nave.
The point cloud data was integrated into Building Information Models (BIM) processes, which allowed architechts to create a digital twin of the cathedral. (Photo: Andrew Tallon (Vassar College / Columbia University))
“Andrew Tallon’s point cloud, well, it’s a bit like listening to a Mahler symphony,” said Prunet, alluding to the scan’s scale and complexity. Prunet continued, “It’s a recording,” but one that “needs to be decrypted.”
Tallon’s laser scan of Notre Dame has proven invaluable in the restoration process. This digital twin, created in 2015, offers unparalleled precision and detail, capturing the cathedral’s every nuance with accuracy up to 5 mm. This level of detail allowed the restoration team to address the structure’s complexities and make informed decisions about the rebuilding process, ultimately helping to preserve Notre Dame’s authenticity and historical integrity.
Swift Navigation and Quectel Wireless Solutions have partnered to enhance GNSS accuracy across various industries. This collaboration integrates Swift’s Skylark Precise Positioning Service with Quectel’s high-precision GNSS modules.
Skylark, a cloud-based GNSS corrections service, is designed to improve standard GNSS accuracy from several meters to a few centimeters. It utilizes advanced atmospheric modeling and a carrier-grade network to provide reliable, scalable, and high-integrity precision.
The partnership offers three Skylark variants: Skylark Cx , Skylark Nx RTK and Skylark Dx. Each variant is tailored to meet specific industry requirements and can be paired with Quectel’s GNSS modules for various applications.
Integration and Applications
Automotive: Quectel’s LG69T module with integrated inertial measurement units combined with Skylark Cx offers lane-level accuracy for intelligent driving systems.
Outdoor Robotics: The LG290P module paired with Skylark Nx RTK offers centimeter-level accuracy for autonomous robots such as robotic lawnmowers.
Micromobility: Quectel’s LC29H module with Skylark Dx achieves decimeter-level accuracy for e-bikes and scooters in urban areas.
UAVs: The LG290P module with Skylark Nx RTK offers high accuracy for fast-moving UAV applications.
Quectel’s LG290P is a quad-band GNSS module designed to deliver high performance for demanding applications, ensuring RTK availability and quality even in challenging environments. When paired with Skylark Nx RTK, the LG290P achieves the centimeter-level accuracy needed to ensure the precision required for applications such as precision agriculture, robotic lawnmowers, surveying and personal robots.
The LC29H module is a dual-band multi-constellation solution with optional dead-reckoning capabilities that supports seamless integration with all Skylark variants and comes in a standard 12.2mm × 16.0mm footprint. Developers can transition from standard positioning to high-precision GNSS without hardware changes while choosing the Skylark variant that meets their specific requirements.
Well, it’s January 2025 and it’s almost here — that is, the release of the beta version of the new, modernized National Spatial Reference System (NSRS) – NATRF2022, PATRF2022, CATRF2022, MATRF2022 and NAPGD2022.
This newsletter will highlight some activities associated with the new NSRS. That said, this is short notice, but I would like to highlight that there is a webinar and workshop that will address the new NSRS scheduled for Jan. 9, 2025 — TRB workshop, “Navigating the Modernized National Spatial Reference System: A Geospatial Odyssey” and NGS webinar “Updates to Products and Models within the North American-Pacific Geopotential Datum of 2022.” I will provide more details on this later in the newsletter.
The modernization of the NSRS is scheduled to occur in 2025 or 2026. NGS intends to release associated tools and services within five years of the modernization. The following details from the Federal Register outline the process for the rollout of the modernized NSRS:
NGS plans to roll out components of the modernized NSRS in 2025 or 2026. As each component is released at beta.ngs.noaa.gov, it can be publicly tested with feedback provided to NGS. The testing will continue for at least six months after the final component is released on beta.ngs.noaa.gov.
Once testing is complete and all modernized NSRS components appear to be stable and correct, the Federal Geodetic Control Subcommittee (FGCS) will be asked to vote to approve the modernized NSRS (likely in 2026). If FGCS approves the modernized NSRS, NGS will publish an FRN announcing the approval of the modernized NSRS and begin a several-month process of transitioning all modernized NSRS components to the official website at geodesy.noaa.gov. During this transition, the beta website may be wiped of submitted data and no further submissions to the NGS IDB (the repository for the current NSRS) will be allowed.
Excerpt from Federal Register Notice. (Photo: Federal Register website)
What does “Only one major improvement to the current NSRS is expected during this time: ITRF2020 will be integrated in all products and services” mean? I understand that one product that ITRF 2020 will be integrated into is the NOAA CORS Network (NCN). The CORS coordinates and velocities will be updated with ITRF 2020 values. That said, NGS datasheets will still provide coordinates in NAD 83 (2011), epoch 2010.0.
As I’ve mentioned in previous newsletters, time really is running out and users need to obtain a working knowledge of the new, modernized National Spatial Reference System. For those attending the104th TRB Annual Meeting on Jan. 5-9, 2025, in Washington, D.C., there is a scheduled workshop on the modernized NSRS. The workshop is sponsored by TRB Geospatial Data Acquisition Technologies Committee (AKD70). The workshop, titled “Navigating the Modernized National Spatial Reference System: A Geospatial Odyssey,” will be held on Thursday, Jan. 9, 2025, from 9:00 am to noon, in room 202B in the Convention Center in Washington, D.C.
Thurs., Jan. 9, 2025 9:00 am to 12:00 pm Room 202B, Convention Center Washington, D.C.
This workshop will cover the following topics:
Why the NSRS is being updated
The key goals of the modernization effort
Timeline, standards and technology considerations
The Geospatial Data Act of 2018 and its impact
There will be a discussion about the replacement of the North American Datum of 1983 and vertical datums and implications for existing workflows
There will also be a discussion about use cases and practical scenarios, how to transition and how to leverage new technology and tools.
For those interested in more information on the TRB AKD70 committee, my August 2024 GPS World Newsletter highlighted activities associated with the Transportation Research Board’s ADK70 Standing Committee on Geospatial Data Acquisition Technologies.
Since the new NSRS will be introduced this year, it is time for users of the NSRS to get familiar with the NOAA Technical Memorandum NOS NGS 92 document titled “Classifications, Standards and Specifications for GNSS Geodetic Control Surveys using OPUS Projects” written by Dave Zenk and Dan Gillins, Ph.D., National Geodetic Survey, published on Oct. 23, 2024. This document provides the specifications users must adhere to when submitting GNSS projects to NGS for review and publication.
Photo: NGS website
The section below explains the purpose of the document. There are a few items that I have highlighted in the preface that users should be aware of:
The document replaces NOAA Technical Memorandum NOS NGS 58 and NOAA Technical Memorandum NOS NGS 59
Users will need to follow these specifications for all projects that will be submitted to NGS using OPUS Projects for review and publication
This publication supplements Standards and Specifications for Geodetic Control Networks issued in September 1984 (Bossler 1984).
This publication replaces NOAA Technical Memorandum NOS NGS 58 Guidelines for Establishing GPS-Derived Ellipsoid Heights (Standards: 2 cm and 5 cm), Version 4.3 (Zilkoski et al. 1997) and also replaces NOAA Technical Memorandum NOS NGS 59 Guidelines for Establishing GPS-Derived Orthometric Heights (Zilkoski et al. 2008).
This publication provides classification, standards, and specifications for GNSS geodetic control surveys that use Global Navigation Satellite Systems (GNSS), which will be submitted to NGS using OPUS Projects for review and publication. These types of surveys were not well-established by the dates of the 1984, 1997, and 2008 publications, nor did OPUS Projects exist. In addition, since 2008 GNSS technology has improved and considerable research has been done into the best practices regarding these surveys and the analyses of achievable results (e.g., Allahyari et al. 2018; El Shouny and Miky 2019; Gillins and Eddy 2015, 2017; Gillins et al. 2019a; Gillins et al. 2019b; Jamieson and Gillins 2018; Park et al. 2018; Schenewerk et al. 2016; Soler and Wang 2016; Wang and Soler 2013; Wang et al. 2017; Weaver et al. 2018). That research supports this publication.
This publication is specifically limited to supporting OPUS Projects (version 5.x), the current North American Datum of 1983 (NAD 83), the North American Vertical Datum of 1988 (NAVD 88) and other current vertical datums that are officially recognized by NGS. Future versions of OPUS Projects and future datums will require revision of this publication.
I highlighted some important sections of the April 2023 webinar in my May 2023 newsletter. Future newsletters will address the specifications in more detail, but I would encourage readers to download the NGS 92 document and the April 13 webinar and slides.
On Dec. 18, 2024, NGS sent an email to individuals on NGS’s listserv informing them that they have made several updates to the NAPGD2022 products and that these updates are now available on the NGS alpha site.
NGS Dec. 18 newsletter. (Photo: NGS website)
To explain the product updates, NGS has scheduled a webinar for Jan. 9, 2025, to discuss the North American-Pacific Geopotential Datum of 2022 (NAPGD2022).
As previously stated in my newsletters, users should obtain a working knowledge of the new, modernized National Spatial Reference System. NGS publicly given presentations that have been collected for public viewing can be downloaded here.
I would like to wish everyone a Happy New Year and a year filled with exciting opportunities.
A roundup of recent products in the GNSS and inertial positioning industry from the December 2024 issue of GPS World magazine.
Mapping
Photo: SPH Engineering
GPR System For terrestrial and airborne applications
The Zond Aero 500 NG is a versatile ground penetrating radar (GPR) system designed for both terrestrial and drone-mounted surveys, suitable for applications such as utility scanning, sinkhole detection, glaciology and geological studies. It operates in dual mode, allowing for ground-based and airborne surveys, enhancing data collection flexibility. Key specifications include a center frequency of 500 MHz, an operating bandwidth of 200 MHz – 900 MHz, a sampling rate of 25,600 samples per second and a scan rate of 50 scans per second, with depth penetration up to 4 meters in average soil conditions. The system features advanced electronics for real-time data collection, which can significantly improve the signal-to-noise ratio. It is compatible with DJI Matrice 300/350 UAVs for airborne applications.
Streamlined Lidar Mapping YellowScan’s Surveyor Ultra integrated with DeltaQuad Evo
Integrating YellowScan’s Surveyor Ultra with the DeltaQuad Evo platform allows users to collect high-precision, high-density data across 1,200 hectares in a single flight while simultaneously capturing lidar and RGB data.
DeltaQuad Evo’s long-range flight capabilities and efficient vertical take-off and landing (VTOL) design, paired with the Surveyor Ultra’s lidar technology, allow users to streamline their workflows to reduce time spent in the air and on post-processing tasks, making it particularly beneficial for large infrastructure projects, forestry analysis and environmental monitoring. The system can be used for surveying, construction, forestry and environmental research.
Airborne Mapping System With a ‘cross-fire’ scan pattern
The VQ-1560 III-S is a dual-channel laser scanning system designed for airborne mapping applications. Its “cross-fire” scan pattern allows for simultaneous forward and backward viewing at the edges of the swath, along with a nadir view in the center. This configuration optimizes point distribution for effective target sampling. With pulse repetition rates reaching up to 4.4 MHz, the VQ-1560 III-S can operate at altitudes of up to 1,600 m above ground level (AGL). At a lower pulse repetition rate of 560 kHz, it can function at altitudes as high as 3,900 m AGL.
The system features inertial measurement unit (IMU) and GNSS integration, with the option to include one or two high-resolution RGB/NIR cameras. It is ideal for professionals in fields such as urban planning, forestry and environmental monitoring.
This bathymetric lidar system is designed for coastal and inland water mapping. It combines high-resolution topographic and bathymetric capabilities, allowing for seamless data collection across land and sea. It can be used for coastal zone management, environmental monitoring, infrastructure planning and more.
Fathom delivers data quickly by leveraging real-time quality control with Onboard and scalable processing with a CARIS workflow. It also includes a built-in topographic lidar and a multispectral camera for coastal surveys at a coverage of 50 km2/hour.
The Geode Grip is a mounting accessory featuring a specialized bracket. It allows users to securely attach smartphones directly to Juniper’s Geode GNSS receivers, offering an integrated and streamlined data collection solution.
The Geode Grip is a tool designed for professionals in surveying, mapping and geographic information systems (GIS) to enhance mobile data collection. It replaces the traditional survey pole with a handheld setup that aims to improve ergonomics. It is ideal for field projects that require precise location data and mobile data collection, such as environmental research, land surveying, agriculture and infrastructure engineering.
New Product Bundle For high-accuracy GNSS applications
Quectel Wireless Solutions has unveiled a new product bundle designed to facilitate the development of high-accuracy GNSS applications. The bundle includes the LG290P GNSS module, which is a quad-band, multi-constellation device capable of receiving signals from various satellite systems, including GPS, GLONASS, Galileo, BDS, QZSS and NavIC. The LG290P is engineered for high precision and supports RTK positioning, allowing for centimeter-level accuracy even in challenging environments. It can be used in diverse applications, such as autonomous vehicles, precision agriculture and surveying.
In addition to the LG290P module, the bundle includes options for either the YEGN103W8A geodetic antenna or the YEGD006U1A patch antenna. Both antennas are designed to operate within the same frequency bands as the GNSS module and are compliant with environmental regulations such as RoHS. This pre-integrated solution simplifies developers’ procurement and integration process by providing a one-stop solution that combines antennas with GNSS modules and RTK correction services.
Lidar Camera Payload For surveying and mapping applications
The RESEPI Ultra LITE is a lightweight payload combining lidar and camera technology for advanced surveying and mapping applications. The system integrates the XT-32 lidar scanner to offer users advanced data accuracy and point density across various operational modes.
It has a compact design with a 5MP colorization camera, making it ideal for small unmanned aerial systems (SUAS) with strict volume constraints. It can be used for aerial and ground-based applications, including utility mapping, construction volumetrics, precision agriculture, forestry, site surveying and mining. Designed for seamless integration, the system is compatible with a wide range of platforms such as Freefly, WISPR, DJI, Sony and mobile setups. Inertial Labs’ proprietary SnapFit adapters ensure quick and secure mounting to enhance the system’s adaptability.
The Leica GS05 is a compact and lightweight GNSS smart antenna designed for surveying tasks, featuring calibration-free tilt compensation. This robust device allows for accurate measurements even when the survey pole is tilted up to 30°, enhancing data collection in challenging environments. Its integration with Leica Geosystems’ portfolio, including Leica Captivate software and total stations, seeks to maximize efficiency. The GS05 can function as both a base and an RTK rover, supporting single base stations and RTK networks such as Leica SmartNet.
Intrepid is a GNSS/INS system integrated with the SeaBat T20-ASV processor and includes a compact IMU and two GNSS antennas, ensuring reliable and precise positioning.
It can automatically stream data to third-party software. This eliminates the need for manual sensor interfacing and reduces downtime. The Intrepid GNSS/INS benefits users in marine surveying applications by providing the precise navigation necessary for operational efficiency. Its intuitive design allows for simple configuration.
Miniature MEMS Sensor-Based IMU Can withstand high shock and vibrations
The KERNEL-201 features three-axis MEMS accelerometers and gyroscopes that offer ultra-low noise, high bandwidth and minimal latency. These characteristics make it ideal for applications such as pointing, stabilization and navigation in systems where performance and size are critical. Its volume of 0.38 cubic inches offers a high dynamic range.
Fully calibrated and temperature-compensated, the unit offers consistent, precise measurements even in challenging environments. It features an in-run bias stability of up to 0.7 deg/hr for gyroscopes and 0.005 mg for accelerometers, along with a low angular random walk (ARW) of 0.065°/√hr and velocity random walk (VRW) of 0.015 m/sec/√hr.
The unit is designed to withstand high shock and vibration while maintaining peak performance, making it suitable for a wide range of challenging applications. The KERNEL-201 can be integrated into various high-level systems, such as motion reference units (MRUs), GPS-aided inertial navigation systems (INS) and attitude and heading reference systems (AHRS). It offers continuous built-in testing (BIT), customizable communication protocols and flexible power options.
Smart Choke Antenna Offers comprehensive GNSS signal reception
The VCS6000XF full band smart choke antenna is engineered for CORS applications. It combines Tallysman Verachoke antenna elements with Septentrio’s Mosaic X5 full-band receiver to offer an integrated solution for OEM CORS systems.
The VCS6000XF offers comprehensive GNSS signal reception, including GPS/QZSS L1/L2/L5, GLONASS G1/G2/G3, Galileo E1/E5a/E5b/E6/E5 AltBoc, BeiDou B1/B2/B2a/B3, NavIC L5, SBAS and L-Band correction services.
The antenna features a 0.5 mm phase center variation and utilizes Calian’s eXtended filtering for near-band signal interference mitigation. The integrated Septentrio Mosaic X5 receiver provides capabilities such as anti-jamming, anti-spoofing, scintillation mitigation and receiver integrity by combining the antenna and receiver in the choke ring antenna.
My previous newsletter highlighted the Fall HSRP meeting that discussed how The Ohio State University and Michigan State University have made great progress in developing useful tools for the development and implementation of the new, modernized National Spatial Reference System (NSRS) in 2025. This newsletter will highlight the updates to vertical datums that The National Oceanic and Atmospheric Administration (NOAA) is working on.
Below is an excerpt of the agenda for the material that I will highlight in this newsletter. As I mentioned in my last newsletter, the HSRP website provides links to reference documents, presentations and recordings. I would encourage everyone to download the presentations or listen to the recordings to obtain all the details.
This newsletter will highlight the session on the vertical datums, including the International Great Lakes Datum (IGLD).
NGS has created a website that provides brief explanations with additional links for detailed information on the National Tidal Datum Epoch (NTDE), International Great Lakes Datum (IGLD) and Gravity for the Redefinition of the Vertical Datum (GRAV-D). The site highlights that NOAA is currently working on three major updates to vertical datums: the 1983-2001 NTDE, the International Great Lakes Datum of 1985 (IGLD 85), and the North American Vertical Datum of 1988 (NAVD 88). The site provides information on why the datums need to be updated.
Excerpt from NTDE. (Photo: NOS website)
The box titled “Excerpt from NTDE“ provides information about the NTDE. It explains what the NTDE is, what NOS is doing, and why the NTDE needs to be updated. If you click on the link titled “National Tidal Datum Epoch update” on the right side of the webpage, it provides more information and links about the NTDE update, such as how will the NTDE update impact you.
The National Tidal Datum Epoch (NTDE) is a 19-year time period established by the National Ocean Service for collecting observations on water levels and calculating tidal datum values (e.g. mean sea level, mean lower low water). The NTDE needs to be regularly revised to account for long-term effects of land movement, sea level rise, and changes in tidal constituents. Tidal datums and their data are used to generate products and services necessary for safe navigation, coastal hazard mitigation, ecosystem research, coastal engineering and marine boundary demarcations.
The NTDE Update: New Tidal Datums are Coming!
NOAA currently utilizes the 1983-2001 National Tidal Datum Epoch. This epoch is now undergoing revision and will be replaced by the fifth iteration of the NTDE. Measurements for the update will be based on water level data spanning the years 2002-2020. Once all data has been collected, NOAA will review, analyze, and generate revised datums. The current proposed release date for new NTDE products is after 2026.
The website also highlights two other NOS projects – the International Great Lakes Datum and the Gravity for the Redefinition of the Vertical Datum (GRAV-D). Again, if you click the “International Great Lakes Datum update” link on the right side of the webpage, it provides more information and links about the IGLD update such as how will the IGLD update impact you. Clicking the “Gravity for the Redefinition of the Vertical Datum” link on the right side of the webpage provides some more information and links about vertical datums.
Photo: MOS website Photo: NOS website
On the second day of the meeting, Jacob Heck, NOAA National Geodetic Survey (NGS), and Sierra Davis, NOAA Center for Operational Oceanographic Products & Services (CO-OPS), gave a presentation providing details on the update to the International Great Lakes Datums of 1985 (IGLD 85). The presentation addressed the following topics:
Define IGLD
Significance of the Great Lakes and need for a common water level datum
Binational coordination and mandates
Why IGLD needs to be updated
Updating the datum
Crucial observational infrastructure
Differences in IGLD (1985) and IGLD (2020)
Future of accessing the datum
Status of IGLD (2020) development
Project milestones to roll-out
Unresolved questions: low water datum
Outreach efforts underway
I have provided a few slides highlighting parts of the presentation. Again, the HSRP website provides links to reference documents, presentations, and recordings. I would encourage everyone to download the presentation or listen to the recording to obtain all the details. The presentation of the IGLD starts at 1:34:00 on the recording.
Photo: HSRP website
They explained the importance of the requirement for the coordination of water levels on the Great Lakes between Canada and the United States and the reason for establishing an international datum.
Photo: HSRP website
Due to land deformation, the IGLD is periodically updated, typically every 25 to 30 years. That is, an uplift in the northern region and subsidence in the southern region of the Great Lakes. See the box titled “Land Deformation in the Great Lakes.”
Land deformation in the Great Lakes. (Photo: HSRP website)
The IGLD was updated in 1955 and then again in 1985. This update is overdue by a few years. That said, it will be aligned with the new modernized NSRS and allow for more seamless updates in the future.
Photo: HSRP website
The presentation highlighted that the expected changes between the old datum, IGLD 85, and the new datum (IGLD 2020) will range from 30 cm to 65 cm.
Photo: HSRP website
The IGLD community measures hydraulic heads for water management using dynamic heights, not orthometric heights. The presentation explained why IGLD uses dynamic heights and how GNSS technology will be used to estimate IGLD dynamic heights.
The IGLD team have been working on getting the message out to the user community. The September 2024 HSRP presentation is just one example. Here’s a summary of the recent and future outreach activities:
Recent engagements:
All-Interested Congressional briefing (May 2024)
Canadian Hydrographic Conference (May 2024)
Canadian Geophysical Union Conference (May 2024)
IAGLR (May 2024)
Soo Locks Engineers Day (June 2024)
Michigan Sea Grant briefing (Jan 2024)
Illinois Coastal Management Program briefing (Sept 2024)
Upcoming:
Coordinating Committee’s ESG (TBD)
Boards of Control (Spring 2025)
2024 Great Lakes Conference, Chicago, IL
US Hydro 2025, Wilmington, NC
IAGLR 2025
The slide titled “Key Takeaways” summarized the essence of their presentation.
This newsletter highlighted NOS’s Tail of Three Datum website. The website provides brief explanations with additional links for detailed information on the National Tidal Datum Epoch (NTDE), International Great Lakes Datum (IGLD), and Gravity for the Redefinition of the Vertical Datum (GRAV-D). The site highlights that NOAA is currently working on updating the 1983-2001 NTDE, IGLD 85, and North American Vertical Datum of 1988 (NAVD 88). The newsletter also discussed the presentation on the International Great Lakes Datum (IGLD) 2020 that was given at the 2024 Fall HSRP meeting. Again, the HSRP website provides links to reference documents, presentations, and recordings. I would encourage everyone to download the presentations or listen to the recordings to obtain all the details.
