Some people have enough math and familiarity with coordinate systems and maps that buying a GPS receiver is a natural next step. Will they start doing their own surveys too??

Well it finally happened yesterday, and why should I be surprised? My fellow county surveyors have advised me that this day would happen... not a matter of IF, but just a matter of WHEN.

A landowner--let's call him Joe--recently bought a section of marshland from his neighbor. He hoped for some better hunting as a result of his acquisition. Armed with a $300 GPS receiver, Joe set out to survey his new land. After all, he had experience ice fishing with this new technology, and Joe was convinced the accuracy was within 6' positionally--good enough to survey his marshland for hunting purposes. After all, he just wanted to put up some deer stands. Needing a place from which to start his GPS survey, Joe asked me for coordinates on the section of land.

I quickly tried to dispel Joe's notion that his $300 receiver could even come close to doing what he envisioned. From what I knew of these inexpensive receivers, their accuracy might be within 100', a significant distance that would render his attempts futile. Joe was insistent, however, and knew I had the information he wanted. He boasted of previous experiences with his inexpensive receiver that allowed him the 6' accuracy he had experienced while ice fishing. He was absolutely convinced that he could do this survey and would have only laughed if I had suggested he hire a land surveyor. Why should he when he could do it himself?

The features on Joe's GPS unit were even more astounding. Everything from inversing to stakeout distances and more. It was weird talking to Joe, who was in the refrigeration business, knowing he knew more terminology about surveying than I knew about refrigeration!

I provided him with published coordinates for the User Densification Network (UDN) station closest to his parcel. I advised him to take his new-fangled, 6' accurate receiver out to one of these stations and see just how inaccurate it was. Assuming that he would find substantial variations from our data, I would then encourage him to stop his surveying attempts at that point. He agreed to report back to me on his findings.

Just as Joe was about to leave, Gus, the custodian, walked in on his daily route emptying trash cans. He had overheard our discussion and chimed in, "Yeah, isn't that GPS stuff great? You can get out the topo maps with the published coordinates on certain waypoints, and the GPS unit takes you right there!" (His unit cost only $150--before the $25 rebate--and he boasted an accuracy of about 35'.)

I got a real education that afternoon. Some people in the general public know more than simply which way is north. Some have enough math and even familiarity with coordinate systems and maps that buying a GPS receiver is a natural next step. Joe the refrigerator guy and Gus the custodian certainly thought it the appropriate next step.

So what's the problem if Joe wants to survey his marshland and Gus wants to check out some waypoints? Seems harmless. Nobody is really surveying anything-- yet.

Later that evening I was reminded of what the federal experts from the National Geodetic Survey (NGS) had talked about at the ACSM conference in Portland. They predicted that within the next five to 10 years, any typical do-it-yourselfer would be able to go down to the local hardware store and get a sub-meter accuracy GPS receiver for less than $300. Could it be that this day has already arrived? Joe's 6' accurate unit was beginning to approach that sub-meter range the NGS experts had talked about.

I then envisioned my neighbor out in his backyard with his hand-held unit, getting ready to drive in an iron pipe "because nobody ever told him where the lot lines were." (He wasn't required to have a survey when he purchased the property. Nor was the neighbor before him. How do these people know where their lot corners are? Somehow they must just know!) My neighbor couldn't care less that I was a licensed surveyor who knows where the lot corners are. How many years before this event could happen:a landowner pounds in a pipe after obtaining some readings from his hand-held GPS unit? Or has it already happened?

On the NRCS "survey" map, the boundaries of this new conservancy area were monumented with 36" rebars driven into the ground with a steel fence post placed adjacent. All distances are shown to the nearest foot. When I asked the NRCS rep to explain more fully everything that he was doing out there, I concluded that in fact he was "land surveying." On the previously recorded "survey" map, the bearing basis was, "The basis of bearing and distance being a Precise Lightweight GPS Receiver (PLGR)."

Do we have some issues here or what?

Although surveyors know better, the fact is sub-meter GPS would seem to be more than accurate enough for 90 percent of landowners in their own attempts to make boundary determinations, especially for rural parcels. The above situation certainly raises legitimate questions for the professional surveying community.

  • Should county land information and mapping personnel (most of them non-surveyors with limited understanding of positional accuracies) release coordinates to the public on demand to assist with hand-held GPS activities? Or should they just direct the inquiring public to a web page address and let them get the coordinates on their own time?
  • From this publicly held information,should the public be allowed to attempt some kind of land surveying activity with hand-held GPS receivers that are becoming more and more accurate, more affordable and more easily available?
  • What is legitimate future activity for the landowner with his or her new hand-held GPS, and what is not?
  • Will professional surveyors find a way to elevate their methods and standards of practice to effectively disqualify non-surveyors in their attempts at surveying, monumenting, mapping or describing land?
  • Is our profession at risk?

    The above answers can only be found in desperately needed new legislation. Without legislation that addresses current real-world situations, our profession will suffer. We need new legislation that elevates the practice of professional land surveying and clearly disqualifies the non-licensed surveyors. Let Mr. and Mrs. Landowner do their thing to a point. After all we live in the USA, the land of freedom and opportunity. But I believe the boundaries between landowner activities and professional surveying activities are beginning to move (or maybe the boundaries never have been clearly defined). We, of all people, are experts on boundaries, and none of us delights in moving or ambiguous boundaries. What about five to 10 years from now? Will the changes be so subtle we fail to see them?

    I heard the following comment at the ACSM conference in Portland: As do-it-yourself tax software has hit the accounting community, so shall GPS technology hit the surveying community. Whereas a tax software program can be a wonderful tool for an accountant, it was designed to be sold to the general population so that anyone could do home accounting and complete tax returns. Can you see any parallels between this and GPS technology and the implications for the general public and our profession?

    My next step will be to run out and check on the stated accuracies for those $300 GPS units. I hope that I'm not surprised. But even then, I know the day is coming. And while I'm checking it out, when I inspect the label I hope to see the following bold warning to the consumer: "This GPS device cannot be used for the determination of land or parcel boundaries, or for any other type of practice requiring the services of a professional land surveyor." I expect on this point I will be disappointed.