Sometimes hands-on data collection just isn’t good enough. In the busy Shizuoka harbor, Weichao Liu of CHC Navigation used the company’s Apache6 marine drone to take a bathymetric survey of a channel in preparation for dredging at a Shizuoka seaport. The Apache6 also collected 3D lidar data above the water’s surface.
In May, CHC Navigation launched the 2020 Edition of the Apache6 USV (unmanned surface vessel), which combines a dual GNSS positioning and heading receiver, stable and reliable hull attitude sensors, and an inertial measurement unit (IMU). The CHCNAV GNSS/INS control box maintains high accuracy during transient GNSS outage, according to CHC Navigation, such as providing uninterrupted surveying while passing under bridges.
Just like an aerial drone, the Apache6 has an auto return feature, and like it’s much larger manned brothers, it uses sonic radar (sonar) to avoid obstacles. Its fully autonomous survey mode is powered by CHCNAV absolute straight line technology so that the craft follows a predetermined path even in adverse current conditions.
Besides 3D bathymetric surveys, the USV has been used for positioning of underwater objects, offshore construction, underwater archaeology and wreck salvage. It is equipped with a high-performance single-beam echosounder, and can be installed with lidar to create a combined marine and terrestrial 3D high-accuracy survey in a single pass, such as for harbor and river surveys with height clearance evaluation.
Feature image: Weichao Liu, a member of CHC Navigation’s technical support staff, prepares to launch an Apache6 unmanned surface vessel, also known as a marine drone. (Photo: CHC Navigation)
The world of mathematics has always been a mysterious one. It is universally loved by those who enjoy STEM-related fields and occupations, while being generally loathed by those who prefer the arts and humanities (similar to the argument with cats versus dogs, but let us not go down that rabbit hole). It would be easy to believe that if each side sticks to their side of the road, there would be peace and harmony in the world.
While I cannot speak for the art and humanities group, I can say with certainty that the STEM-related mathematics professions have been known to disagree with each other on various roles within the surveying and mapping world. While surveying has been around since the beginning of time, various forms of organized mapping systems began in earnest in the 1960s.
When attempts were made to bring the two professions together, each side bristled at being mentioned in the same breath as the other one. The surveyors were the outdoor cowboys with theodolites and tapes, measuring properties and improvements with low precision and accuracy. The mappers, now beginning to be known by the acronym GIS (geographical information system) technicians, were the office computer nerds with punch cards and slide rules.
Each side did not care much for the other — mostly because they did not understand each other’s role in creating the modern infrastructure database. This relationship would last for decades with no relief in sight.
Early (and unresolvable) differences
Each side brought a good argument to the table regarding why the other side was not as important to the authoritative role of map/plat making. For instance, here are the typical stances of each side in the 1970s, before the introduction of personal computers and electronic data collectors.
Surveyors worked on the ground and with actual monuments and improvements. They measured angles and distances to collect the pertinent data and drew by hand said information graphically on paper. Because of the accuracy and precision of the field measurements, adjustments were made to the calculations to resolve the unknown errors within the data collection.
GIS technicians used a combination of hand calculations, drafting and primitive computers to depict information obtained by existing maps and plats. Because the information being reviewed was not obtained through field methods, parcel lines were forced to fit, improvements to be shown with 90-degree corners, and ambiguities with most data issues to be dismissed.
Each side stood their ground (in the field or the office) and maintained the distance and differences until more technological revolutions began to infiltrate their vision. At first blush, one could assume these advancements would bring the two factions together; one would be wrong.
Would you like to play a game?
Photo: RyanJLane/E+/Getty Images
The 1980s are known for many things, but for the surveying and mapping communities, it brought a new way of reviewing and storing spatial data. The introduction of the personal computer and vector-based software in the early part of the decade set the pace for rapid and revolutionary upgrades to each profession.
It was now possible to see on a computer screen what had only been previously possible through manual computation and drafting. As the decade went on, computing speed and storage continued to increase along with the features of software packages.
However, these advancements did little to bring the surveying and mapping professions together; in fact, the technology has been blamed for causing even more of a divide between the two.
Again, each side has their reasons for maintaining their hold on being recognized as the authority on the creation of the cadaster layer.
Surveyors continued to insist because they worked on the ground and with actual monuments and improvements, the process of putting the data into a computerized format only solidified their position.
GIS technicians continued to insist that the refinement of their previous calculations of drafting and mapping into a computerized version further extended their expertise in the mapping world. Also, because many in GIS were specifically trained on computers in college, the work being produced by these members was superior to surveyors.
Even with the improvements in technology from computers, the divide between the two grew. The relationship between surveying and mapping was at an all-time low, so there must be nowhere to go but up, right? Not so fast.
GPS + spatial = data custody battle?
Photo: Magellan
Through the 1990s and beyond, the introduction and subsequent rapid implementation of GPS/GNSS gave new meaning to a previous but rarely used term: geospatial data. Only geodesists and higher-end scientists truly worked with geospatial data because of their professional environment and expertise, but now anyone with a GPS receiver became a geospatial data collector.
Previously, surveyors would measure on a global scale (latitude/longitude and/or state plane coordinates), but this would typically consist of solar and lunar observations under ideal conditions. GIS technicians could only rely on data provided to fit within the location parameters of their projects, which has usually scaled from quadrangle maps.
However, this new technology was being used with data collectors programmed for almost anyone to use with little to no geodesy experience. Turn it on, press a button and voila — a geospatial location in a variety of coordinate systems. No more sun shots, lengthy traverses from obscure NGS monuments, or scaling from the quad sheets.
Finally, the surveying and mapping communities have common ground to work on! It would be easy to assume that walls came down and the two professions mended their fences. The short answer is no; they once again did not. Here is each side’s general take on geospatial abilities:
Surveyors (once again!) continued to insist that because they worked on the ground and with actual monuments and improvements (though now with improved positioning), the process of putting the data into a georeferenced format only solidified their position.
GIS technicians now contended that they, too, could collect the necessary field data using GPS and bypass the need for surveyors. Also, because many in the GIS field were specifically educated to work with spatial data, the information being produced by these members was superior to surveyors’ data.
We now find ourselves flipping the calendar pages well into the 2020s, with little movement on resolving this relationship. But we can change that if we introduce a little friendlier dialogue.
In this corner, the surveyor. In the opposite corner, the GIS technician
When it comes to high accuracy/high-precision data collection for locating existing properties and improvements, there will be little argument that this role is strictly designated to the surveying profession. Technological improvements have made our work more precise and accurate; all while being collected in a georeferenced system. The relationship between the surveyor and geospatial data was previously discussed to demonstrate the importance of our work and determining existing conditions, (see GPS World July 2020 column). The surveyor’s ability to be able to collect an enormous amount of geospatial data for surveying purposes is not being questioned, but the line to where the work encroaches into GIS territory. Spoiler alert: Practically everything the surveyor collects can be considered GIS information as well.
Let us look at the relationship from the GIS perspective. The input and oversight of the parcel layer must rely on the licensed land surveyor to provide, while the GIS community is charged to collect necessary information to include into their database. It would make sense to update existing infrastructure information using current technology or historical archives in which the position of the data can be verified. Either way, it is now going to be referenced by its geospatial position rather than a relationship to a parcel line.
Also, the GIS technicians have the same or better capability to utilize data collectors with GNSS receivers for locating existing improvements for inclusion into their system. Most of these technicians have access to the same sources providing the GNSS equipment and coupled with their education and skills, they can collect the data as well as any survey crew. B
ut does this data collection by a GIS technician fall under most state statutes for surveying without a license? Spoiler alert: The short answer is yes, it does if any data collection includes parcel monumentation and could depict a relationship to a parcel line.
The whole is greater than the sum of its parts
Before both parties of this discussion get their pitchforks and torches to have a “talk” with this author, let us take a step back and reassess where we are today with technology and looking toward a future together. The common element here is the data, but how each party uses the data does vary.
The surveyor typically uses geospatial data for several applications; boundary determination, existing planimetric and topographical conditions, and physical depiction of proposed improvements. The surveyor’s data should be considered as a snapshot in time of the conditions of a particular site or project area.
Because of emerging technology, it is not just manually collected survey points using conventional equipment; it can be point clouds and 3D photographs not possible 20 years ago. The surveyor can be considered a high-tech record keeper and can update information as sites change. All because the collected geospatial data is timestamped and memorialized in a digital database.
GIS professionals, on the other hand, require similar information but for many different purposes. Attributes play a much bigger role in the geospatial data requirements than surveyors because the information found within tells them an important story.
Photo: aydinmutlu/E+/Getty Images
The biggest improvement because of the increasing accuracy of the data is infrastructure. As aging utilities require replacement, locating old facilities can be difficult based upon old mapping. Geospatial data collection provides more reliable locations once old facilities are found, existing conditions are reported, and crucial information about its lifespan is collected for future consideration.
Newly installed utilities will have the luxury of significant attribute data applied to each structure to help with future monitoring and maintenance. These are some of the factor that apply to effective asset management and can be applicable to both public and private clients.
While the surveyor and the mapper use geospatial data for similar yet different uses, the product is generally the same. But this discussion is not just about merging data into one big global database; we need to dig a little deeper on how to grow each side of our professions together.
Growth is never by mere chance; it is the result of forces working together
The surveying and mapping professions have been at a crossroad for some time and both sides continue to ignore each other. Both believe that geospatial data is theirs to control, and they both are right. However, each have a different stake in this geospatial data discussion and need to learn to respect each other’s role. Each side brings a different perspective how to grow and advance our world through effective and efficient surveying and mapping, but they must start talking to realize how much they can grow together.
With a little more focus and education of each other’s roles on both sides, an overlap of responsibilities could mean faster approach to modernizing many aspects of our respective professions. For instance:
Cross training of surveyors in GIS software, data collection requirements, parcel modules, and layer nomenclature
Encourage surveyors to apply for GISCI Certified GIS Professional (GISP) testing
Cross training of GIS professionals and technicians with survey technician programs
Encourage GIS personnel to apply for NSPS Certified Survey Technician (CST) testing
Both surveyors and mappers cross training with data collection systems capable of collecting geospatial data containing specific positional information and attributes
Identifying limitations of various equipment and techniques (i.e. using the right “tool” for the job)
Understanding of positional tolerance (precision versus accuracy) and metadata
Comprehension of coordinate systems and zones, including low distortion projections (LDP)
Distinguishing between surveying and mapping data collection (i.e. boundary/right-of-way determination versus infrastructure collection for inventory)
Light at the end of the tunnel
Technology has introduced our world to many advances not thought possible for our entire existence. The Fourth Industrial Revolution (see GPS World July 2019 column) is now taking aim at industries like surveying and mapping through automation and artificial intelligence capability.
Data is crucial to everything and our respective professions are in the center of the revolution. 2020 and our worldwide pandemic of COVID-19 has been (unfortunately) perfect example of how data affects our world in real time. The more critical and accurate data that is collected, the better we can make assessments of situations.
Surveyors and mappers are doing the same thing with data; survey data helps design our world through establishing accurate conditions, while GIS data helps to evaluate our current conditions and plan for future situations. Both professions rely heavily on data, collected in similar methods, but for separate but similar uses. Each has their strengths to bring to the collective table and can increase the effectiveness of digital modeling going forward.
Photo: PeopleImages/E+/Getty Images
Let’s make a plan
The world is moving toward digital twins, augmented and virtual reality along with autonomous travel; it would be in our best interest that the data used to identify the surroundings for those advancements be correct and seamless from all sources. Let us begin by dropping all the delusions of grandeur for our respective professions and formulate a plan to move forward together. The clock is ticking, and time continues to march on.
Technology continues, and soon Generation Z will be trying to do our work with their laptops and smartphones from the coffee shops without our help. Because they can. See, it is important, isn’t it?
Spot, the robotic dog from Boston Dynamics, is equipped with the Trimble SPS986 smart antenna to collect data. (Photo: Trimble)
Trimble and Boston Dynamics plan to integrate a variety of data-collection technologies with the Spot (robot dog) platform for construction and other site applications.
The jointly developed solution will combine the Spot robot’s autonomous mobility with Trimble’s data-collection sensors and field control software to enable automation of repetitive tasks such as site scans, surveying and progress monitoring, while taking advantage of the robot’s unique capabilities to navigate dynamic and potentially unsafe environments.
The relationship gives Trimble exclusive rights sell and support the Spot robot with integrated scanning, total station and GNSS technologies for the construction market.
The turnkey solution will streamline operation of the robot and provide quality control for missions, enabling construction project managers to easily get a clear picture of jobsite progress on an ongoing basis. Trimble technologies integrated with the robot will enable accurate, scalable and rapid data acquisition, while Trimble’s construction collaboration platforms provide a continuous flow of information between field and office.
Mortenson, a Minneapolis builder, developer and engineering services provider, is one of the first customers to leverage the new technology combination. To eliminate jobsite waste and increase efficiency, the Mortenson team has been piloting Spot robots with the Trimble SPS986 GNSS solutions to autonomously navigate challenging exterior construction environments such as solar farms, continuously documenting site conditions.
An automated and repeatable approach to field-data capture can provide Mortenson with real-time awareness of project status, helping to accelerate project delivery. Through Trimble’s Early Experience Program, contractors such as Mortenson have advanced access to this technology for the purposes of evaluating its suitability in actual construction projects.
The Trimble SPS986 smart antenna. (Trimble: photo)
“Robots will play a crucial role in automated construction workflows and can augment the human workforce by handling dirty, dull and dangerous tasks,” said Martin Holmgren, general manager, Building Field Solutions at Trimble. “Our experience with early adopters like Mortenson gave us visibility into the transformative potential of an integrated solution that seamlessly marries a world-class robot with construction-specific sensors and workflows. We’re excited about this alliance and the potential to bring unprecedented improvements in safety, quality and productivity to our construction customers.”
“We believe the combination of Trimble’s experience and industry leadership in construction technologies and Boston Dynamics’ Spot can transform the way the industry operates,” said Michael Perry, vice president of business development at Boston Dynamics. “The integrated solution will enable any jobsite leader to deploy Spot and Trimble technologies to get an accurate view of construction progress through real-time data collection. With a more comprehensive view of site activity, project managers can take proactive measures to ensure on-time, on-budget and safer project delivery.”
The integrated solution is expected to be available by the second quarter of 2021 through Boston Dynamics, Trimble and select BuildingPoint and SITECH distribution partners in the U.S., Canada, the United Kingdom, the European Union, Australia, New Zealand and Japan.
Through Trimble’s Early Experience Program, select customers will have the opportunity to preview development of the solution in advance of general availability.
The new the GT series of total stations are part of a full workflow solution, including a new field computer, a full-version update to Topcon field and office software and GNSS receivers. The system is designed to work in sync for improved performance and better data handling with built-in, field-to-office connectivity.
The speed, tracking and accuracy of the GT series, combined with the intuitive software system, creates a flexible solution capable of satisfying the technology needs of surveyors and contractors performing survey, layout or machine guidance projects, Topcon said.
“The new total stations perform at a faster 10-Hz positioning update rate,” said Ray Kerwin, director of global product planning. “Combining the GT series with the new field computer and software enhancements, this tracking improvement makes layout easier and guidance more fluid, within an intuitive map view. More layout and survey points can be collected in less time.”
“Surveyors, contractors, as well as heavy machinery automation operators and other construction professionals can benefit from the time-savings and accuracy the series provides,” Kerwin said.
Advanced UltraTrac prism tracking combines optical sensing with a new ultrasonic motor control algorithm designed to maintain superior prism lock.
“Tracking fast-moving targets and maintaining prism lock is now easier on challenging job sites as well as in machine guidance applications. If you’re performing a machine control project where the prism is vibrating on the end of the blade, for instance, the GT will lock onto the prism better and provide smoother machine guidance,” Kerwin said.
Magnet software improves field-based quality reporting and data handling for larger files, graphical processing, and 3D models. Magnet Field features more visual- and map-based workflows in addition to menu-driven functionality popular with power users.
An optional upgrade incorporating hybrid positioning technology helps advanced users get instant location updates via GNSS receivers so positioning data points can be captured, even with the loss of line-of-sight from job site obstructions.
The complete GT series workflow solution — Magnet software, FC-6000 field computer, and HiPer Series GNSS receivers — combine for easy-to-use digital processes designed to help surveyors and contractors increase precision, reduce rework and improve quality control.
Depending on your age, 30 years represents a varying opinion of time. For some, it may seem like forever; for others, it may be a blink of an eye. In respect to technology, it can represent a complete change in the way we do things.
When we turned the calendar page to January 1990, our world had yet to experience the internet, the Hubble telescope had not been deployed to share its fantastic views, and The Simpsons television series was preparing to become the cartoon juggernaut it remains today.
Yes, lots has changed since 1990, and surveying is no exception.
Most professions look back through their history and see various periods where discoveries and inventions revolutionized how the work was completed.
For surveyors, the past 30 years have contained more advancements than all other years combined, with the greatest achievement being the global navigation satellite system (GNSS). With the United States leading the way with its Global Positioning System and the civilian ability to use this measuring system, modern surveying was forever changed.
Solar and lunar observations replaced
Before the implementation of a satellite navigation system, true global navigation was only computed using solar and lunar readings under specific conditions. GPS provided a new frontier for surveyors to establish positions without having to perform traversing from known points or collecting solar/lunar observations.
As the constellation grew, it became easier to use GPS to gain initialization for accurate and redundant position determination. As processor speeds and data storage capability increased, real-time kinematic (RTK) observations became the norm for surveyors everywhere.
The Russian satellite constellation, GLONASS, began operating fully in the late 1990s, and is now included to create today’s GNSS. More satellites provide more coverage, which in turn means more data collection potential.
Many nations and regions are building their own constellations to augment the current GNSS lineup, and also to safeguard the ability to obtain geographic locations when other systems are not available.
Bathymetric surveys made easy
GNSS capability and integration revolutionized several aspects of surveying, including a new and more reliable way of performing bathymetric surveys over large bodies of water. Computerized depth sounders were programmed to coincide readings with GNSS data collection to provide a more accurate and precise method of hydrographic surveying.
The past decade has continued the reliance on GNSS technology with many more devices and applications — not just for the surveyor, but for the public as well. While surveyors are using GNSS receivers on unmanned vehicles such as UAVs and boats, satellite navigation has infiltrated into many of our everyday routines. Cellphones, fitness trackers and our automobiles use this technology to guide us to our destinations.
Surveyors have used the GNSS revolution to create a digital world for better data collection, asset management and increased efficiency. Much has changed in 30 years for the surveyor and the world around us, so we should not be surprised about what technology will bring us next.
The creed “Neither snow nor rain nor heat” may apply to postal workers, but it also could apply to land surveyors.
Today’s surveyors rely on GNSS as a critical tool to enable completion of their tasks, whether defining a property boundary or mapping mining drill sites.
In the articles that follow, surveyors share their success stories using the latest GNSS receivers, software and correction services, all of which are constantly improving to make their tasks easier — despite the terrain or weather conditions.
How one man triumphs
Adam Plumley is a one-man surveying shop in North Carolina. He also wears another hat as a sales, support and product development consultant to Javad GNSS.
“As a land surveyor, I use the equipment every day,” Plumley said. “Javad’s equipment has made it possible for me to operate solo.”
Photo: Stephen Drake
In the project pictured above, Plumley surveyed a 50-acre farm parcel to separate out the six-acre improved northeast corner. “I located the creek, building and improvements on the property east of the road and ran the lines to the creek on the west side of the road.”
The difficult locations on this 2016 survey were at the creeks. It took Plumley up to a half hour to locate the corners and creek points under the tree canopy.
“It would have taken much longer than it did if I had traversed the boundary conventionally,” he said, “not to mention I would have been much more tired at the end of the day.”
Instead, Plumley used a Javad GNSS Triumph LS and Triumph 2 base/rover system with corrections broadcast over the internet.
“I set up the Triumph 2 base about one mile away in an open yard with great sky view. It took me one day to do the initial recon and locations, and another couple of hours to set the new corners the next day,” he said.
Plumley has since upgraded his base receiver to another Triumph LS and added a J-Link 35-watt external radio to his toolbox.
“One thing this and other challenging surveys have taught me is to be patient. To obtain accurate results that you can be confident in takes time.”
About our cover
Our cover photo this month was taken in June 2019 by surveyor Stephen Drake, near his home on the north coast of California. “These redwood forests and very rugged, remote coastal mountains can really test you,” he said. He was using his Javad Triumph-LS rover with the J-Field built-in surveying software, communicating to a Javad GNSS Triumph-2 base station attached to his house. A Verizon Jetpac mobile hotspot (in the black pack hanging below the Triumph-LS in the photo) picks up signals from his home router; the port-forwarded corrections are configured with Javad software.
Stephen calls this his standard configuration, but finds it very flexible. When he is more than 20 miles from home base, he relies on a Triumph-2 and a radio modem placed near the site. He can also use the California Real Time Network (CRTN) with the Jetpac.
He also relies on Javad’s Hybrid RTK, automated post-processing with Javad’s DPOS, automatically generated raw data and quality reports, and the many built-in indicators in J-Field that provide real-time feedback and “give me assurance on almost every measurement before I walk away from it,” he said.
The efficiency that his equipment provides has made Stephen valuable even to firms that already have in-house surveyors, he said. “I honestly do not think I would be here without Javad. It has been a true potent business partner.”
Helping the guard: For the Kentucky Air National Guard, Sibole surveyed for paint lines on the taxiway for C-130 aircraft. (Photo: Matt Sibole)
Like Adam Plumley, Matt Sibole is also a solo surveyor and a Javad GNSS advocate. Based in Kentucky, Sibole tackles up to 140 jobs a year, which he would be unable to do using only a total station or a robotic station. Instead, he relies on the accuracy of GNSS.
He particularly relies on J-Field, the Javad GNSS data-collection software. When using the software’s “Boundary Profile” feature, he can get a fix, then re-initialize and get another fix that he can then compare in real time to the previous fix.
“J-Field keeps all fixes in memory to compare to each other, until you get a group of fixes that agree with each other to verify which fix is the correct fix,” Sibole explained. “We all know that a fix is not necessarily the ‘right’ fix. Javad’s J-Field program will give the user the confidence to know in real time that the shot is correct.”
“J-Field also has a relative accuracy calculator built in to verify that I meet minimum standards in the field before I leave the site,” Sibole said.
Why do we keep hearing about unmanned aircraft all the time, almost everywhere? Fortunately, the buzz has gone beyond next-door neighbors flying dangerously close to your roof or hovering annoyingly around a living room window, and incidents of UAV incursions shutting down airports seem to be getting fewer — improved enforcement and higher penalties may be slowing down these incidents.
Now, UAV users are taking on productive, innovative tasks that couldn’t previously be done, or finishing projects surprisingly quickly and more affordably than ever before, with drones built or adapted for new applications. And equipment manufacturers are creating new sensors customized for use on drones.
Commercial, integrated GNSS/inertial sensors are available that have extremely high performance — previously only available with expensive mil-spec electronics — but in lightweight, small packages, supported by real-time kinematic (RTK), precise point positioning (PPP) corrections or post-processed kinematic (PPK). UAVs carry still, video and multi-spectral cameras generating automatically geocoded outputs, ready for post processing into multi-layered formats — virtually everything a customer could ever dream of having. And lidar sensors enable drones to build accurate models of everything they overfly.
Drones originated largely with military forces. Originally used for forward intelligence gathering, UAV tasks have multiplied and substantially expanded in scope.
Commercial industries were quick to realize the benefits. Before drones, the cost of many tasks done manually would be prohibitive and too time-intensive. Fast, affordable data collection now allows us to quickly tackle and solve many problems.
UAVs can pre-survey large, previously inaccessible tracts of difficult terrain, collect detailed visual representations of entire cities, monitor and support crop growth, or even survey underwater terrain using lidar. UAVs provide crop-growing support by flying autonomous patterns and spraying fields with pesticides or fertilizer. They also are being called into service to spray villages with disinfectant to control the spread of coronavirus, and to survey England’s beaches to monitor coastal erosion.
Photo: Joel Papalini/iStock / Getty Images Plus/Getty Images
Airports are extremely congested spaces, both on land and in the air, making it difficult to conduct surveys that provide insights into their continued monitoring and maintenance.
UAVs create the opportunity to survey such sites safer and faster, reducing disturbances to everyday operations while collecting a level of detail unparalleled by conventional surveying techniques to locate and accurately capture areas in need of maintenance and management on airport runways.
Following several drainage and grading issues throughout a 650-acre airport, Texas-based civil engineering company Gessner Engineering was contracted to provide surveying services to identify the most problematic regions.
The team had to conduct the survey with minimal impact on runway operations. By coordinating with the airport’s air traffic controllers, the team planned a 6–8-hour flight window, with just a few pauses for ongoing traffic, while the airport operated as usual.
Before the flight, the surveyors used senseFly eMotion flight-planning software to carry out pre-flight risk assessments and plan flights. During the survey, four 20-minute flights were completed with the senseFly eBee fixed-wing drone. With its fully autonomous and easy-to-use aerial mapping capabilities, the eBee was able to capture the high-resolution aerial photos needed to map the entire airport. The data was processed using Pix4D Mapper to generate a topographic model including a point cloud with a ground sample distance of 1.5 inches.
The point cloud was so comprehensive, it brought attention to four more areas with drainage issues, providing a level of detail that would not have been possible using only a ground GNSS base station. The UAV survey took one day, compared to four weeks for traditional surveying. This cut the project time in half and significantly reduced disturbances to airport operations.
“The savings in manpower with the shorter surveying time, accurate data retrieved, and the additional drainage issues identified demonstrate the value of drones, as an enabler of solving complex challenges in congested airspaces, especially where time is limited,” said Troy Hittle, general manager, North America, SenseFly. “The success of this project by using UAV equipment has offered new possibilities to both Gessner Engineering and the future of aviation maintenance.”
A famous quote applies to almost everything in our lives: “There is nothing permanent except change.”
This well-known saying is generally credited to the Greek philosopher Heraclitus (500 B.C.E.), although many historians and philosophy experts tend to agree the quote is a combination of many topics found in writings by Heraclitus.
However the quote came to be, it aptly describes the world we live in; especially now with lightspeed advancements in technology. Change is markedly evident in today’s surveying world, and almost no practitioner is exempt from revolutionary enhancements and necessary upgrades to stay current in our profession.
Change is on the horizon
Photo: Trimble
The upcoming NGS 2022 datum change, triggered by advancements in positional accuracies and measurement techniques, has quietly created a groundswell of questions, concern and curiosity of how and why we are at these crossroads. In my September 2019 Survey Scene article, we discussed the background behind the necessity of the upgrade and moving toward a standardized measurement unit, (the “foot”). (For purposes of this article, let’s put aside any mention of using the meter/metric system; the U.S. went down that road in the late 1970s / early 1980s, yet crashed and burned upon implementation. I agree the meter is a more practical unit of measurement, but we need to leave that talk for another day.)
This article will be concentrating on the actual coordinate systems and how significant changes are coming for almost everyone performing surveying measurements. Yes, this means all those construction-based users of GNSS receivers and total stations performing pre-, in-progress and post- construction tasks. Our coordinate world will be turning upside down but, in this case, it will be changes for the good.
Origins of X/Y (otherwise known as Northing/Easting)
We have another philosopher to credit for the concept of coordinate geometry; he is the French scientist Rene Descartes (1596-1650) who was heavily influenced by Plato.
While he may be more well known for his famous quote “I think, therefore I am,” Descartes created what is believed to be the first graphical depiction of geometrical expressions and assigning coordinate values to the results; hence the background behind “Cartesian coordinates.” It is this coordinate system that was utilized by late 1800s/early 1900s surveyors who began using this system to create small networks within urban settings, including New York City, Cincinnati and Atlanta.
As economic expansion continued through the Great Depression and beyond, the need for larger survey networks became more evident. The first state plane coordinate system (SPCS) began in North Carolina in 1933-34 with more states quickly falling in behind them. The main force behind this effort was the U.S. Coastal & Geodetic Survey (now known as National Geodetic Survey), as they utilized many surveyors and engineers that were unemployed due to the Stock Market Crash of 1929 and Great Depression. Technology for the era was limited to theodolites and steel tapes, with most computations being based upon triangulation.
Enter the Electronic Age of surveying
“Big Red” Geodimeter 4D (Photo: National Oceanic and Atmospheric Administration)
Positional and measurement technology remained stagnant until the 1950s and 1960s with the introduction of the electronic distance meter (EDM). Longer measurements could be made with increased accuracy and helped expand our coordinate system capabilities.
These enhancements also led to faster expansion of a nationwide highway system (championed by President Dwight Eisenhower) by simply surveying more efficiently. It is along these highway corridors that state plane coordinate systems were expanded into remote areas and used to verify fractured SPC systems created through solar and/or astronomical means. While positional values at common monuments were found to have significant differences by today’s standards, most error was distributed throughout the network.
Because of the work necessary to complete a survey using a SPCS, it was not practical for any non-governmental project to attempt tying into a known system. Fundamental use of coordinate geometry (CoGo) typically utilized a project base point with a low assumed positional value, (i.e. northing of 1,000, easting of 2,000).
Most surveyors used the same coordinate values for each project and did not have any positional relationship between their projects. While the field portion of the project took a significant amount of time to traverse and collect, the office calculations and manual drafting were also tedious and time-consuming tasks.
Prior to the introduction of the handheld calculator in the early 1970s, traverse computations were completed manually using sine/cosine/tangent tables, traverse adjustment (i.e. compass, transit and Bowditch rule) and double distance meridian (DMD) methods. Even as the programmable calculator became the computation method of choice, regularly producing survey data in SPCS was still years away.
Along with the electronic theodolite and the personal computer with computation software, the introduction of the data collector quietly revolutionized the amount of data that could be stored and efficiently plotted for surveys. But even with the increased efficiencies, there was one big drawback to utilizing this electronic data collection with SPCS; most hardware was limited to values and significant figures not acceptable to using large coordinate values. Some tried truncating SPCS values but often found the trouble not worth the effort, not to mention having projects large enough to be affected by grid-to-ground scale factors (another topic for another day).
Fast forward to the 1980s and the introduction of ultimate surveying black box, the GPS receiver. Positional accuracy through static GPS sessions was now better than ever and allowed surveyors to cover greater distances in shorter time periods. It was the implementation of the GPS receiver (and subsequent reduction in cost of entry for its use) that allowed the surveyor to embrace the state plane coordinate system more than ever. Also addressed with the new technology was the ability for the data collector to handle larger coordinate values with increased significant figures.
As RTK and subsequent RTN systems have allowed for more efficient use of GNSS technology, the surveying profession has now overwhelmed the existing monument network and exposed the deficiencies of NAD83 and our various SPCS zones nationwide. NGS has done an excellent job for many years refining and adjusting the national datums (both horizontal and vertical) by augmenting the systems with new data and “turning the screws” as deemed necessary to provide a reliable network.
If it is not broken, why fix it?
The existing SPCS zones and overall NAD83 system works well but we will need to circle back to the quote in the opening paragraph: “There is nothing permanent except change.”
Research, not just completed by NGS but many other respected agencies and laboratories worldwide, has shown that our existing datums have significant flaws due to many factors. These factors include, but are not limited to, tectonic plate shifting, previous survey data that doesn’t meet today’s positional and measurement standards, and limitations in terrestrial measurements.
We are overdue for an upgrade to the national system and design of new policies and procedures has taken time and lots of hard work. NGS has created a new framework that will adapt to the changing needs of a state and/or regional authority.
But what does this mean for the surveyor, the contractor and anyone else in the geospatial world that uses state plane coordinates for the basis of data?
Image: National Geodetic Survey (Michael Dennis)
As discussed in the last article, NGS has been busy creating a new framework with a proposed implementation of 2022-2023. While NGS is creating the specifications, policies and procedures for the new system, it will be up to each state to decide if they want to keep their existing SPCS zones, change to a new scheme, and/or request that additional smaller zones be included for consideration. NGS, in keeping with existing policy, will work with each state to update their SPC definitions, but only if the state engages NGS during the setup period. Otherwise, NGS will apply the new datum specification to the existing zone(s).
What does this mean to the everyday surveyor?
For an example on how a state can revise their SPCS, let’s use Illinois and its plan to revise current zones. Illinois currently implements a two-zone system (East and West, lengthwise through the state) based upon a transverse Mercator projection.
For several years, GIS users and other agencies have discussed creating a single-zone system across the entire state for ease of use. Because of the size of the state and availability of RTN coverage to some remote areas, the realization of this new system has been on hold. Also, it is understood the distortion in data accuracy across a system this large would not be suitable for survey-grade applications.
Forward to 2019 and the NGS datum upgrade along with a substantial effort by several equipment manufacturers to install CORS stations across the state for broader RTN coverage (and the not-too-distant future rollout of 5G cellphone service). RTN coverage for mapping grade data collection is now readily available nearly everywhere in Illinois, so the potential of a single-zone system is now not far-fetched.
It should be noted that if Illinois decides to convert to a single-zone system, NGS will only recognize that system for future computations and documentation and the two-zone system will be scrapped. It will fall to each practitioner to convert their existing data and projects to the single-zone system if they choose to use it, but it will have some drawbacks due to the distortion of the larger system.
Image: National Geodetic Survey (Michael Dennis)
Enter the low distortion projection (LDP) system. Like other states, Illinois is discussing a potential LDP system containing 32-34 regions statewide for more accurate coordinate system development. These regions are being studied to concentrate on larger urban centers and areas where growth potential is predicted. Regions such as the Chicago, St. Louis and Peoria metropolitan areas are being highlighted for major LDP system use by not just surveyors but government and GIS analysts.
Having a coordinate system with less distortion and more accuracy can provide more reliable information for the survey but also provide more value for the residents and businesses. By concentrating the coordinate system on smaller areas through an LDP, surveyors will literally be using a communal network like their old calibrated or localized network systems of days past. The coordinates will still be large but the integrity of the data will be higher due to the reduced distortion of the system projection.
This system will also virtually eliminate the need to have a grid-to-ground scale factor because of the lack of distortion. So we will now have a large statewide system for mapping and smaller regional systems for accurate survey data going forward; sounds like a good plan, right?
Making a significant change increases our capabilities
Not to sound like a broken record, but let’s revisit the quote by Heraclitus one more time: “There is nothing permanent except change.”
Most people don’t like change, even if it is for the better. Surveyors are notoriously famous for not wanting change. Many surveyors I know would not embrace early GPS not simply due to cost, but more of not understanding how it works. They also didn’t understand how to embrace state plane coordinates and having survey data that will be compatible with their competitors. Most of those surveyors now are using it, but only because the data collectors have become more user friendly.
But why will this change be harder for most? Depending on where one is and how their state is going to adapt will affect that change. If your state is not changing any zones, they will have a -2 to +4.5-meter coordinate shift depending on where they are located. For states like Illinois and potentially changing from two zones (East and West) to a single zone and dozens of regional LDP systems, it will be a bit harder to translate all your existing survey data to the new systems if necessary.
There are several potential pitfalls in front of us if we aren’t careful. Here are a couple of scenarios to consider:
Image: National Geodetic Survey (Michael Dennis)
Understanding the general change in datum values
Converting old data to new system for reuse (additional time consideration)
For practitioners working in several LDP regions, emphasize the importance of correct zone
Software and equipment firmware updates
Older unsupported data collectors
Compatibility with current and archived GIS data
Conversions of government agency-specific data and benchmark
Major milestone dates:
Establishing a date in which all new survey data will use the new datum
Establish a date in which all design projects will utilize the new datum
Establish a date when all construction layout will utilize the new datum
These zone/LDP system changes also will be affected if your state is currently recognizing the U.S. Survey Foot and will be changing to the “foot” per my last article and ongoing NGS discussions. That change will also precipitate additional review and care for compliance of any old data to new systems.
As creatures of habit, change and adaptation moves us forward
Here’s the bottom line: We need to make this change in order to efficiently address future mapping needs and positional accuracies. Because of technology and evolution of measuring devices, we now know there are other factors that play into our coordinate systems.
As the world becomes more reliant on digital data and information, it will be critical that the right geospatial information is tied to it. There is nothing permanent except change, but change can also be for the better.
Trimble released its X7 3D laser scanning system, designed for designed for surveying, construction, industrial and forensic applications, at Intergeo 2019.
SenseFly, a drone solutions provider, will be demonstrating its drone solutions at Intergeo 2019, which will take place Sept. 17-19 in Stuttgart, Germany.
According to the company, visitors to its booth will be able to explore the flexibility of senseFly’s eBee X drone and its role in optimizing GIS and surveying workflows to achieve high quality outputs, such as centimeter-precise 3D point clouds, orthomosaics and digital surface models.
Attendees will be able to learn about the range of payloads and software solutions the eBee X platform can be used with, including the senseFly Aeria X, senseFly Duet T, senseFly S.O.D.A., senseFly S.O.D.A. 3D, MicaSense RedEdge-MX and Parrot Sequoia.
The senseFly team will also be hosting a series of Meet the Experts sessions on-stand featuring guest speakers and demos from senseFly partners such as Pix4D, ALLNAV and Harxon. The 10-minute talks will be followed by Q&A sessions.
“Our expert team also enables us to deliver the knowledge and insight our users need to navigate the changing landscape as drone technology continues to garner greater public and legislative attention worldwide,” said Gilles Labossière, CEO of senseFly. “Our customers’ needs are constantly evolving, and it’s vital for us to ensure that our products and solutions are as dynamic and versatile as they are to meet their unique and complex challenges.”
SenseFly’s can be found at booth B3.078, Hall 3, at Intergeo 2019.
