Changes in surveying technology.

The New Year marks the beginning of my 14th year in the surveying profession. As I look back on the changes that have taken place since I first started, I’m amazed to think about the technological advances that have taken place in those few short years. I know that when some of the “old-timers” read this article, my examples will pale in comparison to some of theirs. But I’m still amazed by how much things have changed in such a short time span.

I had used an old theodolite while in the Air Force to track weather balloons, so I learned to read angles using verniers. The first instrument I used as a survey technician was a newer Lietz theodolite, so learning to read the angles on a micrometer seemed like a major technological leap to me. We also had an old top-mounted EDM at that time that had already seen better days. The Lietz was very modern compared to what I had previously used, and being new to surveying, I didn’t even know that EDM technology existed. My crew chief at that time explained to me that the other two crews (we were the third of three crews) used a newer type of instrument called a “total station.” A month later I was transferred to one of those crews and was introduced to a Topcon GTS 3B total station. The possibilities seemed endless!

The following year I had the opportunity to work on the crew that utilized GPS for the first time within our company. The job consisted of establishing positions on about 100 government corners in northern Lower Michigan. The work took place in January and February and many of the corners were off road so we used snowmobiles to get to them. The GPS constellation was not complete at the time so the observations had to take place at night in order to get sufficient satellite data. I used my military duffel bag as a backpack to transport all of the equipment to my corner locations on the snowmobile. Everything together weighed about 60 pounds. Our occupation times were about two hours, and we’d run two sessions per night with four receivers. That’s why it took two months to do the job.

In my early days in this career, a topo job was accomplished by establishing a “baseline” between control points and measuring the station and offset to each of the topographic features with a tape. This information would be recorded by hand in a fieldbook or drawn onto a sketch on clipboard paper. Once everything was located horizontally we’d then use a level to obtain the necessary vertical information. By 1992, I was working as a crew chief and my supervisors had discovered that I liked this new electronic stuff. When they decided to purchase a new total station along with a new HP-48SX with a data collection package, I was the one who got to learn how to use it. Within a couple years, each of our crews had a data collector and nobody was doing “baseline” topo anymore.

The HP-48 with its software package changed the way we did a lot of things. Topo information could now be recorded electronically. Codes could now be entered for each item located. This added the appropriate symbol or line when downloaded to the computer in the office. I’m still impressed when I watch a topo file being imported into a CAD program. The crew chief’s steps seem to be magically retraced on the screen.

The procedures that we used for many other tasks were also radically changed with new technology. Much of the data previously recorded in a fieldbook could now be recorded electronically in the data collector. Many of our procedures used for construction staking were changed because of the advantages of using the new software over the older techniques.

Today, we’re still using the HP-48s, but have begun phasing them out in favor of the new TDS Ranger data collector. The Ranger has a Windows CE operating system that gives us a whole new set of options. The Total Stations are still around and probably will be for a while, but many improvements have been made. We now have a couple of robotic instruments that give one person the capability of doing what previously took a minimum of two to do. GPS equipment can’t even be compared to what we used 12 years ago. We’ve had real-time capability for a while, which gives us corrected positions to centimeter level accuracy. The constellation has been complete since the early '90s so nighttime observations are no longer required (but are still possible). With today’s dual-frequency receivers, in some cases, sufficient data can be obtained in as little as eight minutes for a static network rather than the two hours that it used to. With the RTK capability, one person with a rover can accomplish significantly more than any two-person crew using a total station in the same amount of time. The availability of the CORS (Continuously Operating Reference Station) data has also increased potential efficiency by decreasing the number of receivers necessary to occupy control points. Fifteen years ago, who would have imagined?

I haven’t even mentioned the changes in the office. We had two computers in the office the day I started and a room full of draftsmen with boards. The last drafting board disappeared from our office a few years ago. Every desk now has a computer. Think about how E-mail and the Internet have changed the way we do things in just the last five years! It’ll be very interesting to see what’s in store for us in the next five!

Because of the new technology that is available today, our level of accuracy is unprecedented, and our efficiency has increased immeasurably. That does not mean that the monumentation we find that was set using a transit and tape 50 years ago is not in the correct position. It is true that we have the ability to make any type of measurement much more accurately than in past years, but the methods and conditions used in making the original measurements must be considered when evaluating the positions. Take advantage of the new technology, embrace the new technology, but at the same time don’t forget past instrumentation and methods, and learn to evaluate data accordingly. As impressive as the new technology may be, it’s just as impressive to think about the accuracy achieved by some of the surveyors who laid out this great country 150 to 200 years ago.