A Bench Mark in Time
May 1, 2010
On May 14, 2000, I walked across the stage at the University of Akron with my new degree in hand. I was one of only four survey program graduates who attended the commencement ceremony--there were just nine of us in the class at the university's Summit College--but I was proud to represent the program with the distinction of being at the top of my class and top of the college. A few months later, I would take one of the toughest exams of my life and become a survey intern for the State of Ohio. Several years after that, I would sit for the principles and practices exam and be able to represent myself as a professional land surveyor, first in Ohio and then later in Michigan.
I’ve now left my mark in at least a half-dozen states. The surveying profession has changed substantially in the past decade. Where have these changes taken us? And how can we ensure that we’re leaving a positive legacy for the next generation of professionals?
In my college internships and right after college, we used total station instruments, ran closed traverses and did level loops with automatic levels. The work was hard but noble. Our crews paid close attention to detail. We referenced land corners and kept detailed notes. We checked and rechecked measurements, making sure everything fit right while using common sense. Level runs were adjusted if they didn’t close right on, but they were always closed loops. If the traverses were not closed by the book, we took side shots to check for any errors. Chains were still in our trucks, although they were mainly used for referencing corners.
Today, those processes, along with the equipment, are all considered “old school.” The mechanical total station and its operator have been largely replaced with a magnetically driven robot. In fact, with its ability to quickly solve triangles, the robot is now the most-common one-person tool for transferring vertical distances. The chain has been left to rust, and the automatic level is now a bar-code reader. The skill required to run a closed traverse and make the accompanying adjustment is now just a memory, and the simple process of adjusting the reticle because of eye fatigue is also history. The knowledge of how to read stadia and even how to read the numbers on a Philadelphia rod is fading as well, and the Lenker rod isn’t even considered.
The evolution of GPS technology could be a story of its own. I feel lucky to have been introduced to surveying when GPS equipment was readily available to private survey companies. Of course, we had differential GPS (DGPS) technology, which was dubbed a “dinosaur” just a few years after my career began. We used a single rover with two base stations for redundancy; the additional base station helped us ensure that we could solve the coordinates of at least one baseline.
DGPS taught me how to respect the Global Positioning System. I learned about the strength of figures and what Dave Andrus, PS, of J.C. Andrus & Associates, calls “geometric common sense.” My crew members and I knew the limits of our figures and the distances we could stretch with our baselines. But the most valuable lesson I learned from working with DGPS over the years was to truly understand the technology, including the satellite coverage, mask angles, occupation times, multipath, obstructions and, most importantly, the limits of the equipment. If any of these parameters were abused or neglected, the end result would be a float solution later on in the day when everything was downloaded and processed, and we would have to return to the field.
For the most part, the days of DGPS are over. Many firms don’t even have real-time kinematic (RTK) GPS with a base and rover; instead, they only have a rover. The terminology has shifted from GPS to the more-global GNSS, and reference networks like Trimble’s Virtual Reference Station (VRS) network have made GNSS surveying as simple as pushing a button.
The tools in my survey toolbox are amazing, and it’s hard to imagine not having them. But the respect for the equipment too often is set aside in favor of simplicity and speed. Today’s surveyors simply push a few buttons and expect instant calculations. The results are sometimes unresolved float solutions and bad initializations that end in poor surveys, not to mention increased liability and legal nightmares. Inexperienced surveyors have no reason to doubt this equipment because it is all they know. They use it beyond its capabilities and sign their names to the results. Much like DGPS, redundancy and common sense are becoming discarded relics.
The Consequences of Change
I was taught from the books of Walter G. Robillard, Esq., RLS, and clearly understand the distinction between lost, obliterated and existent corners. Single proportion was infrequently used and was always, as Robillard says, “a rule of last resort.” Over the past decade, I have rarely called a corner “lost” and would use every available resource to prove it existent or obliterated. I agree with POB columnist Jeffery Lucas, PLS, Esq., that “there are no lost corners” and that if enough research is performed and enough resources are used, a conclusion is always found. I also agree that just because new technology makes it simpler and easier to “calculate” or “establish” corners doesn’t necessarily make such practices correct.
The same goes for the location of the center of sections. I was taught by multiple “old school” surveyors. They knew the importance of a monumented center. If the monumented center did not fit the theoretical center, we would note accordingly. We would not simply create a center based on technology and possibly mess up the entire square mile. When I first started in this profession, we either had to traverse the whole mile or run control with the GPS. We always searched for every corner regardless of how difficult or time consuming that search might be.
Today, a section can be run out literally as fast as one can drive around it. Moreover, corners are far too often being “established” or “calculated” rather than being found or set. It takes far more time to hike to the center of a section or any off-road point than it does to simply calculate it.
We should all be concerned about this trend. The consequences of these actions will follow us far into the future. Boundaries will be disputed, legal rights trampled and monuments ignored--all in the name of technology and the ability to save time and money.
A Coordinate-Based World
Because I used to run closed traverses and calculate coordinates based on latitude and departure, I know where the coordinates originate (e.g., angle and distance). Many users of today’s robotic and GPS equipment have no idea how the coordinate values appear on their screen. They don’t understand or even care to understand what is happening inside the equipment. Yet, if any one of the vast number of settings--including foot definitions, geoid models and even state plane coordinate zones--is incorrect, those coordinate values will be erroneous. Scale factors are now set, and the latest trend is simply a site calibration.
A few years ago, I taught a surveying course. I arrived early one day and changed all the prism constants on the total stations from -30 millimeters to zero before the lab began. I had the students do a simple routine: Set up, measure a straight line, and set a point at 100 feet and then 200 feet. I then had them set up in the middle, backsight one of the points, measure, and then flop the scope and measure the other point. Everyone was thoroughly confused when the simple numbers didn’t add up. The easiest lab of the semester soon became the most confusing, but this experience made it memorable. Most of the students had never heard of a prism constant, yet some had been working in the field for years.
I understand and accept that it is becoming a coordinate-based world. But it’s essential to understand how the coordinates are created. Surveyors need to educate themselves on the settings in the data collectors, check the prism constants, and learn the full consequences of doing a site calibration.
The One-Person Crew
In May 2009, I wrote a guest note in the POB eNews about a conference session I attended that was led by POB columnist Milton Denny. I wrote that Denny had commented about how many surveyors are working solo these days with the aid of GPS, robotics, etc., and that he had begun to wonder who will be teaching the next generation of surveyors.
In response, many readers e-mailed me with stories of how other surveyors had mentored them and how they are making sure they pass down their knowledge. Still, I can’t help but think that many of today’s young surveyors lack this kind of guidance because of the widespread use of one-person crews. Passing down knowledge to the next generation is a responsibility that falls to both the educators and the current generation of professionals. We must all do our part.
Safety is another consideration. Our work often requires us to be in ditches, forests, fields or other areas where we are prone to injury. If we are working alone, there is no one to help.
Technology has aided us tremendously in our work. However, we must be careful not to allow technology to shortchange our responsibilities to each other and to our clients.
The Times They Are a-Changin’
I miss the days when field books were composed of paper instead of memory cards, but change is inevitable. This decade will undoubtedly bring new opportunities and continued advances in the surveying profession. Yet as we move toward the future and embrace ever-more-sophisticated technologies, I hope that the “old school” principles such as referencing land corners through swing ties, implementing closed loops and traverses, and using common sense continue to apply. As different as today’s GNSS technology might seem from the technologies used in the past, the fundamental elements remain the same. We must continue to look to the horizon for precision and accuracy rather than relying exclusively on the data collector screen.
1. Robillard, Walt, et al, “Brown’s Boundary Control & Legal Principles,” 4th Ed., John Wiley & Sons Inc., Hoboken, N.J., p. 218.
2. Lucas, Jeffery, “There are no lost corners,” POB, Vol. 25, No. 4, Jan. 2010, p. 24.