Benjamin Franklin, the surveyor said, “If you don’t remember your mistakes, you are destined to repeat them”. I often ask myself, “What lessons do we need to remember as surveyors?” I have 33 years of my own to evaluate. Now, as a proponent of terrestrial Mobile LiDAR surveying Scanning (TMLS), I understand the importance of this hindsight. After all, surveyors by nature are not animals of change. The common mind-set has been that the profession will fragment further to specialization driven by technology. The 5% of leading edge surveyors bring along the remaining percentage over an extended period of time. I am amazed at the number of surveyors who now utilize a GPS system like we used to break out the level, tape and transit. GPS has proven to be a truly incredible change in the work flow and physical effort needed in the field which equates to huge man hour savings.
My survey mentor told a story about how he had performed a lot survey for a home owner. When he went to collect his fee of $100.00 the home owner said…
"$100.00, but you were only here for a short time and you only had to set one corner".
My mentor replied, "Well, it was $5.00 to set the corner and $95.00 to know where to set it".
Knowledge is powerful and in today’s world of digital gadgets it can be a whirlwind that my mentor would not only embrace but excel in.
Did GIS change the role of the surveyor? Did GPS change the role of the surveyor? Will TMLS change the role of the surveyor? The answer to all of these questions is no, but it did! (Spoken like a surveyor.) The truth is… lately as I travel across America speaking to surveyors and engineers, I am finding a greater acceptance for this technology because of its faster and safer way to collect spatial data. Surveyors are slowly embracing TMLS, not as a way to phase out their job but as a way to expand business and increase opportunities. In fact, the past two months Terrametrix has been exposed to more than 4,000 surveyors at various conferences and workshops. The tide is changing, after all how do you teach a computer spatial recognition?
What I am finding, however, is the questioning of accuracy, again and again and again. How accurate is it? It’s a valid and important question and the answer is… survey grade accuracy. It’s discerning to me that until now, until TMLS provided the transparency of repeat data, what a traditional surveyor shot in the field was considered “gospel” accuracy. The difference is we can see the variance of data in TMLS. The field book was seldom questioned, however, you have to consider… send that same rod and instrument crew out again then tell me how close will they be on their second pass? Now add traffic. Add the GPS error budget. Add total station error budget.
The confusion of TMLS accuracy is not whether or not it is trusted data, the confusion lies in is the transparency of data accuracy. It has been proven through field trials that TMLS accuracy is survey grade… 8–13mm, and just like GPS or a total station you have to use the correct procedures to obtain survey grade data. How precise is your rodman at 600,000 points a second?
