The U.S. Army Corps of Engineers, St. Louis District, has contracted with Aero-Graphics for photogrammetric and lidar surveying and mapping for the next five years. Aero-Graphics is a 56-year-old geospatial services company headquartered in Salt Lake City, Utah.
The $16 million contract is an indefinite delivery indefinite quantity (IDIQ), firm-fixed-price contract.
The services requested are for photogrammetric mapping and related surveys, as well as the preparation of maps for advance planning, design, real property, construction, land-use and land-type monitoring, and analysis for various projects.
“Being awarded the USACE St. Louis District contract is an honor, especially because we will support the Center of Expertise for Photogrammetric Mapping,” said Casey Francis, Aero-Graphics co-president. “Their focus on geospatial rapid response and technical proficiency is directly aligned with Aero-Graphics’ unique process. Our entire team looks forward to supporting this exciting contract.”
Francis added, “Our mantra is ‘agile responses to ever-changing environments.’ We look forward to demonstrating our unique abilities to the St. Louis District, enabling them to accomplish their mission of securing our nation, energizing our economy, and reducing disaster risk.”
New business development specialist hired
Angela Arriaga
In other company news, Aero-Graphics appointed Angela Arriaga as its new business development specialist. In her role, Arriaga will be responsible for expanding the company’s client base.
Arriaga comes to Aero-Graphics with more than 10 years of experience in geospatial, aviation, processing and surveying. “Angela has a strong background in operations management in lidar and ortho imagery,” Francis said.
“Aero-Graphics has always been a staple in this industry with an outstanding reputation and a commitment to excellence,” Arriaga said. “It’s exciting to be a part of this incredible team. The leadership is fully committed to professionalism, passion and enthusiasm for the work. I am looking forward to help continue its expansion and the success of our customers.”
Mason and Dixon were pioneers in bringing geodetic astronomy to the American colonies. Through the efforts of the Mason and Dixon Line Preservation Partnership, we can promote this scientific contribution along with the placement of the boundary stones.
Ask surveyors why they became engaged in the profession and why they had continued with it, most will centralize on one aspect: working outside. A career that allowed them to work outside in various environments, solving problems, and being part of a solution is typically the main answer they give.
Depending on the task at hand, a day in the field surveying can take one to several places, including urban/suburban neighborhoods, construction sites, and agricultural/wooded farmland.
View from Mason Dixon Stone #95 looking toward Maryland. (Image: Tim Burch)
My entry into surveying was no different. From residential sites, condominium surveys, boundary and topographic surveys, and construction layout, my early years in surveying covered a lot of territory. While my career eventually took me out of the field and into an office managerial role, and now into leading a professional association, it does not erase the roots of one’s surveying knowledge and experience. Opportunities to be part of the field exercises of a survey, especially a boundary survey, are typically rare and subject to time constraints.
Having spent all my life in the flat topography of Illinois and surrounded by farm fields and urban sprawl, the ability to see for miles over the various horizons was the norm. Coupling these conditions with the Public Land Survey System (PLSS) and use of GNSS technology, it makes for a great environment for the professional surveyor to go about his or her work.
However, the United States covers many areas and contains distinct types of terrain, ecosystems and demographic groups that provide challenges to the surveyor. While I assumed moving from Illinois to the mid-Atlantic region would require adaptation, an opportunity to help retrace and inventory a significant part of American history provided me with an eye-opening experience. It also helped me appreciate the legacy of our surveying forefathers.
A small title dispute
Even in the 17th and 18th centuries, disagreeing title descriptions to common lands was an issue. Reviewing two conflicting legal descriptions describing adjacent land boundaries is the basis of this survey exercise, and thus began a symbolic establishment of a famous boundary line that would lead to political and demographic ramifications in later years.
Here is the situation:
1632: King Charles I grants to Cecilius Calvert (second Lord Baltimore), a royal charter for establishing a new colony north of Virginia to a point “which lieth under the Fortieth degree of north latitude” and westward to the source of the Potomac.
1681: King Charles II (eldest son of Charles I) grants William Penn a royal charter of land between 43° N and a line extending westward from “a Circle drawn at twelve miles distance from New Castle…” to “the beginning of the fortieth degree….”
1682: King Charles II grants to William Penn an additional grant in the Delaware peninsula, which Lord Baltimore claimed.
1685: King Charles II directed his Board of Trade and Plantations to issue an edict ordering that territory to be divide equally, the western half going to Baltimore. This order endorsed Calvert’s claim of a boundary line being 19 miles to the north and providing him claim to Philadelphia. Part of the edict placed a burden on Calvert of providing a survey to authenticate the claim, but the survey was not completed. The boundary would eventually be established 19 miles to the south.
1731-1732: Charles Calvert, the fifth Lord Baltimore, petitioned King George II for help in demarcating the final boundary. He agreed on the final boundaries; however, a commission created to study the legal claims failed to deliver instructions in which a survey would be based upon. Calvert disputed its interpretation and refused to implement the arrangements.
1730s: Ongoing conflict over the disputed land claimed by both people from Pennsylvania and Maryland resulted in Cresap’s War, named after the land agent, Thomas Cresap, hired by Calvert to settle new development. In 1736, Cresap was accused of murder, arrested by Pennsylvania officials and his housed burned was burned down.
1750: After years of bitter controversy, British Lord Chancellor Hardwicke ruled that the southern boundary of Pennsylvania should be a line running westward from the point at which the line dividing the Delaware peninsula was tangential to a circle with a radius of 12 miles from the center of Newcastle.
After 100+ years of boundary disputes and deadly confrontations, in 1760 Frederick Calvert was directed by the English monarch to accept the terms of the 1732 treaty.
Penn-Calvert Land Grant Agreement. (Image: National Archives)
The unfilled challenge, however, was to commission a survey to establish the terms of the agreed-upon boundary. Given that the final location of the Pennsylvania/Maryland border was geographically based (approximate latitude of N 39°43’20”), the surveyors chosen to establish this line would have to be knowledgeable in such calculations.
Finding qualified surveyors in the colonies turned into a bigger challenge than first considered, so the monarchy assigned two surveyors from the Royal Society (full name: Royal Society of London for Improving Natural Knowledge). Enter Jeremiah Dixon (surveyor) and Charles Mason (astronomer) — the field party charged with tackling this monumental deed.
The survey calculations of Charles Mason. (Image: National Archives)
We know them by name for the lines they established in fulfilling the requirements of the boundary agreement, but how they accomplished their task remains a mystery to most. Previous exercises using geographical position determination was used in the sailing and shipping industries with lesser degrees of accuracy. This assignment would require higher levels of accuracy and precision, hence the reason for calling upon Dixon and Mason for the task.
By using geodetic astronomy, they were able to determine accurate (for the period) geographical positions of latitude. Geodetic astronomy is the art and science for determining, by astronomical observations, the positions of points on the earth and the azimuths of the geodetic lines connecting such points. It relies on spherical astronomy, using calculations and techniques developed by the Greeks in the second century A.D.
Besides the knowledge of performing the necessary calculations, the duo would also need to possess instruments to gather the accurate astronomical information. The survey of the agreed-upon line was to be established upon a constant line of latitude. The survey procedures would require turning angles (azimuths) from their meridian westwardly with accuracy not yet utilized in the New World.
Both instruments used for the project were built by John Bird, a well-respected instrument maker in London. The equipment consisted of a zenith sector, capable of measuring to two arc seconds. No field azimuth instrument of this accuracy existed in that era. They also brought a converted telescope/level set up for surveying purposes. This transit has no divided horizontal “plate,” only a tangent screw for slow azimuth motion.
In addition to the instruments and astronomical tables from Greenwich and Paris, the duo relied on a highly precise clock for marking time by the second, which was quite advanced for the period.
Dixon and Mason spent the better part of 1766-67 establishing the agreed-upon line using astronomy via the Bird instruments and taking copious notes documenting their calculations and survey conditions.
Field notes from Jeremiah Dixon. (Image: National Archives)
The markers set along the way —stone monuments chiseled back in England with demarcations — were quite accurately established despite the primitive nature of equipment and methodology for the survey. Mason and Dixon laid out the 233-mile long “West Line” in short segments, following the latitude arc of approximately N39°43’20” for 233 miles westward.
Old line versus new technology
In 2020, the Maryland Geological Survey (MGS) and the Pennsylvania Historical & Museum Commission (PHMC), members of the Mason and Dixon Line Preservation Partnership, began a new initiative to inventory these historic markers and submit them for inclusion into the National Registry. If accepted, the monuments will be part of a program established to help protect and preserve these physical boundary markers that define the boundary between the two states.
Part of the inventory has been the recovery and position confirmation by volunteer surveyors from the Maryland Society of Surveyors (MSS) and the Pennsylvania Society of Land Surveyors (PSLS). Using a geographic information system (GIS) app designed and implemented by the Maryland Geological Survey (MGS), volunteer retracers capture significant attributes about each monument.
While reestablishing the latitude/longitude of the recovered monuments with a smartphone or handheld GPS receiver is sufficient, several volunteers have used high-accuracy surveying equipment to determine a monument’s position.
Incredibly, the variation in the location of a given monument is well within reasonable tolerances from the originally intended installation. Also, because of GNSS technology, we now know more about continental drift. Because of this additional knowledge, 250+ years of tectonic plate movement should be considered when making these positional comparisons.
It should be noted that these monuments are a critical component of the boundary between states, and therefore must be considered senior to many other survey corners set after them. We cannot get lost in the sentimental aspect of recovering the monuments and not acknowledge the fact these points are the gospel when it comes to defining these state boundaries.
A Midwesterner in a ‘foreign’ land
My surveying career, as noted above, was solely in a state that is 200 years old, based upon the PLSS, and does not carry the history of the Mason-Dixon era of line establishment. So, when I was presented with the opportunity to join fellow surveying professionals from Maryland and Pennsylvania in recovering Mason-Dixon monuments for the inventory, I found it an easy event to join.
The planned meeting spot was a local fast food place at 8 a.m. on a sunny Saturday. Being it was in a small town, there were several groups meeting for their normal Saturday coffee klatches. Hearing a group mention “surveying,” I found my opening to identify myself as a fellow surveyor. After opening pleasantries, we settled into a game plan for recovering the targeted monuments for the day.
Planning a day of stone monument recovery along the Mason-Dixon line. (Photo: Tim Burch)
We settled on our assignments and enthusiastically went about our way. My partner for the day was Eric Gladhill, a Pennsylvania professional surveyor and veteran of Mason-Dixon monument retracement. In addition to his volunteer work, he has also authored several articles and a book on his surveying experiences, so it was quickly evident that we were in for a good day.
The first monument was not difficult to get to, and seeing it nearly brought a tear to my eye. Here before me was my first sighting of a Mason-Dixon monument stone, and it was simply amazing. Standing there admiring this 250+ year old stone, hand cut and carved in England and brought here by ship to be specifically placed on this line, I could not help but realize the importance of this monument.
This line, and these stones, were the culmination of two land grants that disagreed with each other more than 400 years ago. We were standing in the same location as a large survey party once did, where they observed the stars to determine an accurate position and directed axmen to clear the untamed forest to establish this important line. While it was a warm and sunny day, it gave me a chill to know we were following in the footsteps of our surveying forefathers.
Mason Dixon Stone #98 – My first recovery! (Photo: Tim Burch)
We continued our way and recovered six more monuments, including a crown stone. Crown stones were placed at 5-mile intervals. The detail in the carvings for most of the monuments was noticeably clear, and is a testament to the craftsmanship of the era’s stonecutters.
Mason Dixon Stone #95, a crown stone. (Photo: Tim Burch)
While locating these historic monuments, were felt we were standing on hallowed ground. The location of this line was important enough that people, both indigenous and settlers, fought for the right to build their lives there.
This was also a line that would be the site of many battles during the Civil War. Observing these monuments drove home the fact that surveyors play important roles in establishing land ownership both today as well as almost 300 years ago.
Mason Dixon Stone #93, a Maryland side marking. (Photo: Tim Burch)
Mason and Dixon were pioneers in bringing geodetic astronomy to the American colonies. Their work has provided inspiration for future generations of geospatial professionals, yet most of the public does not know about that portion of their contribution. Hopefully, through the efforts of the “Mason and Dixon Line Preservation Partnership,” we can promote this scientific contribution of Mason and Dixon along with the placement of the boundary stones.
My heartfelt thanks go out to Eric along with Wayne Aubertin and Rob Kundrick (Appalachian Chapter of the Maryland Society of Surveyors) for allowing me to join them for this task. They gave me a chance to be a true surveyor again and connect the past with the future.
The AR3 maritime surveillance drone, usually launched horizontally, can be launched vertically with attachable propellers. (Photo Tekever)
Tekever, a European maritime surveillance provider, has unveiled a new version of its AR3 unmanned aerial system (UAS). The AR3 now has a “hot-swappable” vertical-takeoff-and-landing (VTOL) capability, able to switch from horizontal launch to vertical. It also now has integrated synthetic aperture radar (SAR).
Tekever made the announcement at AUVSI Xponential 2022 in Orlando, Florida. The company specializes in maritime surveillance services that deliver actionable real-time intelligence. The AR3 is a shipborne UAS designed to support multiple types of maritime and land-based missions up to 16 hours. With the upgrade, the AR3 becomes more operationally flexible, the company said.
“Users no longer have to choose between having pure fixed-wing assets for longer endurance missions, or fixed-wing VTOL assets for more challenging deployment conditions,” explained Ricardo Mendes, Tekever CEO. “The AR3 combines both capabilities and provides users with the ability to decide the configuration just moments before takeoff.”
The newly added SAR provides the AR3 with a vastly greater operational range, and the ability to effectively detect, recognize and identify targets under any weather condition. Covering more than 20,000 square nautical miles per mission, the new AR3 is the suitable for wide-area surveillance missions.
“Our SAR, which we named Gamasar in honor of the Portuguese navigator Vasco da Gama, is designed and built by Tekever specifically to provide our customers with capabilities that are typically only available through much larger systems,” Mendes said. “With an extremely reduced logistics footprint, the unprecedented VTOL flexibility and the unique capabilities provided by Gamasar, the new AR3 is a game changer that provides our customers with tremendous value and cost effectiveness.”
Auterion has introduced new capabilities for high-precision mapping missions and automated, end-to-end data workflows to make mapping more efficient, reliable and powerful across industries.
Unveiled at AUVSI Xponential 2022, updates to the Auterion OS serve enterprises with diverse use cases that need component and payload flexibility, alongside a centralized and streamlined software workflow.
Advantages for customers include:
Availability of precise mapping data in real time and automated processing that enables fast decision-making, saving time, ensuring consistency and reducing human errors.
Standardized process across any Auterion-powered vehicles, bringing an improved user experience, reducing training time, and affording easy scaling of operations.
Connectivity that enables automated end-to-end workflows with no need for manual data transfer, and integration with third-party data-processing software such as Esri Site Scan or Propeller.
“The mapping and workflow features included in this latest release of Auterion’s software focus on use cases from our enterprise customers,” said Markus Achtelik, vice president of engineering at Auterion. “We’re making sure that workflows are thoughtfully designed to meet customer needs and that the data they require is collected, automatically processed and streamlined through Auterion’s software platform for immediate use and longer term analysis.”
Auterion’s new platform capabilities are achieved through the enhancement of tightly integrated components. For example, the ground control app provides precise mission execution with fully integrated control of payloads, such as the Sony α7R IV camera. Then, capture and storage of geotagged images on the drone occur in real time.
Next, image data correction and processing happen seamlessly. This kind of automated workflow illustrates Auterion’s commitment to building efficient operational solutions for enterprise-ready drones, the company said.
“Auterion’s software is updated with its expanding open ecosystem in mind,” added Achtelik. “That gives customers the best options on the market, offering greater flexibility and choice to meet enterprise quality, scale, and regulatory needs.”
Juniper Systems has introduced the Geode GNS3 GNSS receiver, which allows users to collect real-time GNSS data with sub-meter, sub-foot and decimeter accuracy options.
With a scalable platform, users can purchase the level of accuracy they need now, while having the option to increase accuracy in the future.
“This new Geode offers expanded accuracy options to our users,” said John Florio, Geode product manager at Juniper Systems. “We set out to deliver a product that is scalable to our user’s needs. The GNS3 allows users to purchase a receiver that fits their accuracy needs at the moment, while still being able to unlock greater accuracy through subscriptions when that need arises.”
Photo: Juniper Systems
Available in both single-frequency and upgradable multi-frequency antenna configurations, users have the level of accuracy needed to get the job done. The Geode GNS3S offers superb sub-meter accuracy with a single-frequency antenna. The GNS3M allows for scalable accuracy; its multi-frequency antenna support all constellations on L1, L2 and L5 frequencies.
Multi-frequency signal tracking, together with Atlas L-band correction subscriptions, allow for up to decimeter accuracy. As with previous Geode devices, SBAS corrections are available for sub-meter accuracy in certain regions.
Both models also support local differential GNSS real-time kinematic (RTK) and continuously operating reference networks (CORS) through the Geode Connect NTRIP client.
“Providing Atlas corrections and scalable accuracy allows for the Geode to be used in new markets,” Florio said. “A few of these include water utility locating, agriculture and irrigation mapping, mapping projects in remote locations where other correction services are not available, and any other mapping need that requires a higher degree of accuracy.”
The Geode GNS3 offers flexible connectivity and can be used with Windows, Android, iPhone and iPad devices. A USB-C port allows for data transfer and fast charging and an antenna port allows for the use of an external antenna.
The Geode GNS3 GNSS receiver is now available worldwide.
Winners will present their projects at ION GNSS+ 2022 in Denver
The Institute of Navigation’s Satellite Division, in partnership with Google, will host the 2nd annual Smartphone Decimeter Challenge, with the winning teams presenting their methods at the ION GNSS+ 2022 meeting. ION GNSS+ 2022 takes place Sept. 19–23 at the Hyatt Regency Denver, adjacent to the Colorado Convention Centerx.
The Smartphone Decimeter Challenge is designed to advance research in smartphone GNSS positioning accuracy using state-of-the-art algorithms and technologies such as advanced machine learning models and precision GNSS algorithms.
While standard receivers using signals from GPS, other GNSS (Galileo, BeiDou, GLONASS) and regional systems (QZSS and IRNSS) provide accuracy between 3 and 10 meters (often worse in urban environments), better location can be obtained by processing carrier-phase measurements, inertial measurement unit (IMU) data, and base station corrections.
Teams will use datasets collected using the GPS receivers and IMUs of Android smartphones to compute location down to an accuracy of decimeters. Mobile users will benefit from lane-level-accuracy-based services, enhanced experience in location-based gaming, and greater specificity in location of road safety issues.
Winner selection is based on the accuracy of results from the test datasets compared to highly accurate ground truth. The top three winners will receive prizes valued at $15,000+ including a guaranteed speaking slot at the highly competitive ION GNSS+ 2022 conference (subject to technical paper and ION presentation requirements); a travel subsidy; and complimentary registration to attend ION GNSS+ 2022 in Denver.
The Open PNT Industry Alliance (OPIA) issued a statement regarding the recently approved U.S. Fiscal Year 2022 Appropriations Act. The alliance advocates for support of alternative positioning, navigation and timing (PNT) services.
In its statement, the 21 corporate members express support for the funding provided to the Department of Transportation to pursue alternative forms of PNT.
The OPIA also highlights a change to the National Timing Resilience and Security Act that eliminates the “land-based” technology requirement. The consensus among members is that the adjustment was needed so that the law would allow for multiple forms of PNT, a concept that aligns with the diverse technology principles of the coalition.
The Consolidated Appropriations Act for Fiscal Year 2022 (H.R. 2471) promotes robust positioning, navigation, and timing (PNT) technologies and preserves competition that drives innovation in the market.
Important Funding for PNT Services
The FY 2022 Appropriations Act, passed by the U.S. Congress and signed into law by President Biden on March 15, 2022, provides $15 million for the U.S. Department of Transportation (U.S. DOT) to establish a program that will support the U.S. government’s pursuit of many types of alternative PNT. The legislation aligns with U.S. DOT’s January 2021 “Complementary PNT and GPS Backup Technologies Demonstration Report” and summarizes how the funding will be applied.
OPIA encourages U.S. DOT to apply this funding to procure alternative PNT services and supplementary solutions that will protect critical infrastructure. Our members are prepared to engage civil government officials and critical infrastructure owners and operators to match needs with solutions.
Critical Change to Existing PNT Law
The National Timing Resilience and Security Act of 2018 (NTRSA) focused attention on the need to reinforce GPS. Congress subsequently recognized that NTRSA would be harmful to the commercial PNT market. The FY 2022 Appropriations Act revises the NTRSA to align with the U.S. DOT’s 2021 report that “the best strategy for achieving resilient PNT service is to pursue multiple technologies to promote diversity in the PNT functions that support transportation and other critical infrastructure sectors.”
This straightforward change to the NTRSA is as follows:
“Section 312(a) of title 49 United States Code, shall be amended by striking ‘land-based,’ after ‘operation of a’.” When the revised objective of the NTRSA is read in context, it is evident that the law is now fully inclusive of multiple forms of alternative PNT:
Subject to the availability of appropriations, the Secretary of Transportation shall provide for the establishment, sustainment, and operation of a land-based, resilient, and reliable alternative timing system (1) to reduce critical dependencies and provide a complement to and backup for the timing component of the Global Positioning System (referred to in this section as “GPS”); and (2) to ensure the availability of uncorrupted and non-degraded timing signals for military and civilian users in the event that GPS timing signals are corrupted, degraded, unreliable, or otherwise unavailable.
This move by Congress comports with the findings of the U.S. DOT’s report on PNT which state that “suitable and mature technologies are available in the private sector and offer owners and operators of critical infrastructure a diverse array of complementary PNT services to meet their GPS backup needs. Because such needs are application-specific, GPS resilience across all critical infrastructure sectors will require a plurality of diverse PNT technologies to meet multiple use cases.”
The commonsense modification to the NTRSA allows multiple alternatives to GPS and other global navigation satellite systems (GNSS) to deliver against a complex and ever-expanding set of institutional and end-user requirements.
The alignment with OPIA’s bedrock principles is clear:
A diverse technological landscape offers varied operational characteristics to support all critical infrastructure sectors.
True resilience requires diversity that a sole-source technology cannot meet in terms of reliability, performance, and the flexibility to address evolving attack prevention and threat response needs.
The ingenuity of the private sector marketplace will drive the emergence of multiple cost-effective GPS/GNSS alternatives that evolve according to technological innovations and market dynamics.
Open PNT Industry Alliance members provide what critical infrastructure needs for resilience: alternative forms of PNT that complement GPS/GNSS as well as augmentation services, security solutions, and hardware/software for time synchronization, navigation and location applications.
This image shows the effect of increased elevation on surface area and obstacle avoidance. (Image: Advanced Navigation)
By Simon Harris, Advanced Navigation
Lidar-based surveying is increasing in demand across a range of industries. Recent market analyses indicate that lidar surveying is a multi-billion dollar industry that is expected to deliver sustained growth for years to come. As lidar technology matures and performance increases, its range of use is broadening into surveying more complex and difficult terrain or at speeds and in environments previously unsuited to such technology. Naturally, increasing diversity and performance brings about demands for greater reliability, speed and accuracy whilst remaining within physical and regulatory limitations.
Keeping pace with market demands in UAV and rail sector lidar surveying is increasingly challenging and requires an evolving synthesis between the acquisition and processing of lidar and GNSS-INS georeferencing data. Companies such as Cordel and its subsidiary Nextcore are taking advantage of the latest technologies to develop systems that are setting new benchmarks in these sectors.
Benefits of Altitude, Faster Lidar and Precision INS
UAV lidar surveying is capable of high-resolution surveys of complex terrain, vegetated areas and in light conditions that may be unsuitable to photogrammetry. These qualities make it a preferred option in many applications. However, it must remain cost-competitive with alternative solutions to become widely adopted by the surveying industry.
Typical UAV lidar surveying is performed at ~40m AGL. This altitude commonly presents collision risks with terrain and vegetation and imposes limits where the topography changes dramatically, such as voids that increase AGL beyond acceptable limits. Higher altitude surveying, therefore, offers obvious advantages, but also deeply challenges lidar sensors and the INS. Any mismatch in operational performance and accuracy between these inevitably degrades survey quality and severely limits use of the system.
Nextcore accepted the challenge and set about developing a viable solution that could maintain a point cloud density of 200-500 points per m2 from a target altitude of 70 m. This equates to generating lidar point cloud data at millions of points per second. Achieving this required a GNSS-INS that provided suitably precise georeferencing data. Because survey data is derived from a source that is in constant motion in 3D space, the capability of the GNSS-INS is paramount in producing a digital twin of value and is critical to mission success.
After testing and evaluating various INSs from different manufacturers, Nextcore coupled its lidar with Advanced Navigation’s MEMs-based Certus Evo INS, which provides near-FOG performance and has a drift rate of 0.2 degrees/hour. This combination yielded exceptional results that allowed them to vastly extend the altitude ceiling to 120m while retaining consistent, accurate survey data.
“Operation at this altitude not only reduces the risk of collisions with trees, it enables surveyors to cover larger areas, greatly improving the solution’s efficiency,” said Ashley Cox, founder and COO of Nextcore.
Higher altitudes tend to increase the lidar swath width. The typical swath width at ~50m altitude is ~120m, depending on actual altitude and the resulting angle of incidence of lidar toward the edges of the swath. At 120m, a reliable swath width of 180m was achieved. This is a 50% increase over previous, equating to approximately 33% fewer flight-lines to survey a given area — a notable boost for productivity and efficiency to surveyors.
Example of rail track lidar showing encroaching vegetation, with associated map and location information. The yellow circle in the lidar data shows vegetation that is starting to intrude into the train’s path. (Images: Advanced Navigation)
Payload minimization also was a critical aspect in the search for an INS, as surveyors are always seeking longer flying time. This only can be achieved with a lighter technology stack payload. The team used an OEM version of the INS for a smaller form factor that could be integrated within a single ruggedized housing. This allows a design with greater strength, weather resistance and efficient payload setup.
“The industry is constantly seeking lighter payloads for longer flight times and to fit on smaller, safer UAVs,” Cox said. “Regulatory restrictions challenge the industry to meet certain specifications. The same is true for UAV lidar. We hit a ceiling. We need to be able to improve on that, although what we’re achieving now is a real game changer.”
The resulting survey material contains lidar point cloud data and the geo-referencing data from the INS. All data processing is performed post-flight to ensure the highest possible accuracy. PPK is used for correction of GNSS-INS position, roll, pitch and heading data. The processed INS data is then combined with the processed point cloud data to provide absolute position to the point cloud. This system realized consistent 30~40mm precision at 120m AGL. Nextcore has integrated the lidar and INS processing platforms to automate the synthesis of data sets, reducing the survey completion time. Depending on the survey’s size and complexity, this solution can process survey data into a 3D map within 30 minutes of mission completion.
Nextcore used a Certus Evo GNSS receiver, which internally uses the u-blox ZED-F9P chip. It logs GPS L1, L2, GLONASS L1, L2, Galileo GalE1, E5, and BeiDou B1, B2 frequencies at 8 Hz. It used the Kinematica correction service running a PPK filter.
Lidar sensors have become light enough to mount on UAVs (Photo: Advanced Navigation)
Scanning Rail Corridors Super Fast
Aerial surveying is not the only environment to present challenges to lidar and INS.
Train-mounted lidar for automated track and rail corridor surveying is another burgeoning market. This application typically uses lidar and position data to detect and identify areas of the railway that require maintenance and, perhaps more importantly, preventive maintenance. Rail surveying presents unique demands, including operating at speeds of 160km/h (100mp/h) or more, maintaining position accuracy during GNSS outages and variable environmental conditions.
Land-based surveying provides flexibility for selecting an INS compared to aerial applications, as size and weight are usually irrelevant. Rail surveying also requires an INS that provides the necessary performance while tolerating vibration and erratic movement from junctions, points and signals, and be absolutely dependable in GNSS-denied situations. Cox’s team found that the greater accuracy and better drift stability of FOG INS over MEMS provided an ideal platform for generating reliable and accurate paths of train trajectory.
Cordel tested Advanced Navigation’s Boreas digital FOG INS as a potential solution. Testing was carried out using cars as a simulation, travelling complex routes in two directions then overlaying the lidar point clouds to check for discrepancies or unsynchronized areas. The results provided the confidence to put the Boreas into service.
Railways typically traverse deep cuttings, lengthy tunnels and other environments that disrupt GNSS. It is mission-critical that the INS can apply dead reckoning the instant GNSS is disrupted and maintain accurate position for the entirety of the outage. Reliable path and location data during GNSS disruptions is central to the viability of automated rail surveying. Blind spots or zones of unreliable route data cannot be tolerated by rail operators from safety, track availability and financial perspectives.
The Cordel AI lidar analysis system can be “tuned” to the required metrics and is capable of self-learning. The AI enables the system to pre-emptively identify and flag areas of concern before they become an actual problem or hazard. Examples include measuring track gauge and alignment, ballast distribution and coverage, and clearance between potential hazards to the train. The entire route is logged, creating a “Google map” of the railway that maintains a historical record of survey data each time the track is used.
Clients can then view a representation of the lidar data to get a clear understanding of any issues and how to respond before sending personnel or assets to a location. This enables intervention before safety is compromised or remedial works become large-scale and disruptive. As a result, rail service providers can maintain safer railways, deliver more reliable services, and minimize operating costs.
Florida Power & Light to deploy 13 autonomous drones, with plans for hundreds more in coming years to monitor statewide power grid
UAV company Percepto will deploy autonomous drones to monitor Florida power substations and distribution grids across the state.
Florida Power & Light (FPL) will deploy drone-in-a-box technology statewide, which Percepto claims is the largest commercial autonomous drone project in the world.
FPL serves the northeast and southern half of Florida. (Image: Florida Public Service Commission)
Serving more than 11 million people in Florida, FPL uses Percepto’s Autonomous Inspection and Monitoring (AIM) solution powered by drones to perform routine infrastructure inspection and monitoring.
In the first phase of the project, 13 drones will take flight in the West Palm Beach area this year, with long-term plans to field hundreds of Percepto over the next five years.
The drone-in-a-box solution was the first to pass Level 5 hurricane testing at a wind speed of up to 155 mph, making it suitable for minimizing incident response times and power outages in Florida.
Percepto has served FPL since 2018, working closely to develop optimized drone monitoring solutions and build consensus and compliance with Federal Aviation Administration (FAA) regulations. The FAA issued a nationwide waiver for FPL to fly Percepto drones for surveillance and inspection purposes at sites owned and serviced by FPL.
As part of its ongoing work with the FAA, Percepto is a member of the Beyond Visual Line of Sight (BVLOS) Aviation Rulemaking Committee (ARC) that has provided its regulatory recommendations to fully incorporate highly automated BVLOS operations flights in the national airspace.
The drones in operation across the state will be coordinated on a single platform through Percepto’s AIM solution. With Percepto AIM, drones can be operated remotely to ensure that they work together in sync, providing maximum coverage at the sites they monitor.
Topcon Positioning Group has announced a new option for Caterpillar Next Gen excavator users to leverage Topcon 3D machine control functionality together with Cat Assist features. As a result of new compatibility of the Topcon 3D Excavator System with Caterpillar factory-installed NGH sensors, customers will experience simplified installation of the Topcon aftermarket system into Caterpillar’s existing 2D excavator systems, in coordination with Topcon and Caterpillar dealers.
“With increased pressure for productivity and accuracy, and the industry’s need for skilled operators, the solution is timely,” said Jamie Williamson, Topcon executive vice president. “The customer will have the benefit of Topcon 3D Excavator System and Caterpillar Assist features working together. Once the user is acquainted with the combined system, it will be easy to be a more productive operator.”
The Topcon system is designed to provide real-time, dynamic, on-screen bucket location and design views, resulting in the operator cutting grade faster and more accurately. The operator can create, cut and check designs directly from the cab. Together with Caterpillar boom and bucket automation, operators can deliver quality work all day long with less fatigue, according to Topcon.
“Seen & Heard” is a monthly feature of GPS World magazine, traveling the world to capture interesting and unusual news stories involving the GNSS/PNT industry.
A “BeiDou positioning system for subways” began construction March 20 on the Beijing subway capital airport express line. The project will cover a 30-kilometer-long section of the express line, including five stations. To provide positioning, the BeiDou Navigation Satellite System (BDS) will be combined with 5G for indoor positioning or in areas where the satellite signals are blocked. The system will improve the positioning accuracy in subways to less than 2 meters, making it available for vehicle dispatching, passenger transport organization and emergency response. In addition, it allows passengers to use their phones to navigate and position in complex environments in subway stations through three-dimensional navigation.
Image: ESA
THE SHAPE OF OCEAN WATER
The European Space Agency (ESA) investigated a technique to precisely measure sea-surface topography based on an idea submitted by the Institute for Space Studies of Catalonia (IEEC). The technique involves GNSS reflectometry — signals that have been reflected off of the sea surface at very low angles. The ESA-funded activity involved developing a GNSS receiver and setting up an experiment in the Balearic Islands to collect GNSS signals reflected off the sea surface. The team linked the coherence of the reflected signals to wave height and elevation angle of GNSS satellites. The team then processed the signals for optimized measurements of the shape of the sea surface, useful in applications such as ocean current forecasting, climate research, ship routing, cable laying and debris tracking.
Image: Japan network/Ohta and Ohzono, Tohoku University
CELLPHONE NETWORK DETECTS EARTHQUAKES
A paper published Feb. 9 in Earth, Planets and Space by Japanese Earth science researchers analyzed the potential of a dense network of GNSS receivers, installed at cellphone base stations, to monitor crustal deformation as an early warning indicator of seismic activity. Results showed that data from a cellphone network can rival the precision of data from a government-run GNSS receiver network, while providing more complete geographic coverage. Japanese cellphone carriers have constructed networks of GNSS receivers to improve locational information for such purposes as automated driving. The study examined the potential of a GNSS network built by SoftBank Corp. to play a role in monitoring crustal deformation.
Photo: Falklands Maritime Heritage Trust
ENDURANCE IN POLAR ICE
Researchers have discovered the remarkably well-preserved wreck of polar explorer Ernest Shackleton’s ship, Endurance, a century after it was swallowed up by Antarctic ice. A team of marine archaeologists, engineers and other scientists used an icebreaker ship and underwater drones to locate the wreck at the bottom of the Weddell Sea, near the Antarctica Peninsula. The ship is at a depth of 3,008 meters, 4 miles south of the position originally recorded by navigator Frank Worsley. The expedition team used two Saab autonomous underwater vehicles to explore in a pre-programmed search pattern. After the ship was located, technicians swapped out sonar equipment for a high-resolution camera and a laser-surveying device to make highly detailed scans of the site.
Amapping service provider birthed during the 2014 Ukraine conflict is tracking the current war through crowdsourced photos, Tweets, posts, news and other channels.
The Live Universal Awareness Mapwas founded by a team of software developers and journalists to inform the world about the Ukraine conflict. By viewer request, it quickly expanded to cover other regions, including Syria, Israel-Palestine and “Islamic State war” news. Today, it covers more than 30 regions and topics, offers translations in several languages, and can be used on mobile browsers via its own Android and iOS apps.
The independent global news and information site is dedicated to factual reporting of important topics such as conflicts, human rights issues, protests, terrorism, weapons deployment, health matters, natural disasters and weather-related stories from a vast array of sources.
Its map-centric approach to the organization of information allows viewers to quickly find relevant stories in geographies of their interest. Events are archived, and can be reviewed for analysis or historical trends. “Through our big-data analysis methods, we aim to help predict and prevent future conflicts, minimize the impact of disasters, and assist travelers around the world in making conscious decisions about their security throughout their journeys,” the service states.
Liveuamap uses proprietary software tools, such as artificial-intelligence web crawlers, to find newsworthy stories. These sources are then forwarded to a group of expert analysts for fact checking. In the final step, editors decide which facts and stories should be displayed on the map to minimize spam.
An improvement under development will enable viewers to create and manage their own maps.
The U.S. Army Corps of Engineers, St. Louis District, has contracted with Aero-Graphics for photogrammetric and lidar surveying and mapping for the next five years. Aero-Graphics is a 56-year-old geospatial services company headquartered in Salt Lake City, Utah.
