Network corrected real-time is a technological approach to high precision GPS/ GNSS positioning that has been theorized about, studied, experimented with, and implemented in various academic, scientific, and commercial forms for nearly a decade. Many of the various approaches share the fruits of past research, algorithms, and technological tools; some which are in common.
Click Here to begin the series,
or view the Article PDF's Here
Test Yourself
Got Answers?
Test your knowledge with NCEES-level questions. Start HERE
Meet the Authors
Check out our fine lineup of writers. Each an expert in his or her field.
A 83Kb PDF of this article is available by clicking HERE
In the March issue, I discussed the imminent demise of both field-run and aerial topography at the hand of freely-available satellite data. Those particular wheels have been in motion for some time and there is little we surveyors can (or should) do about it. This topic touched off several other discussions with colleagues, and brought to mind the recent dust-up in California with respect to machine control.
In case you are not from the Golden State, or have been otherwise occupied for the last several months, the controversy surrounds GPS-controlled construction equipment and whether or not contractors employing it are illegally practicing surveying. Essentially, machine control bypasses the surveyor translation of design-to-field, instead using a target digital terrain model and RTK GPS. Attaching that combination to earthmoving equipment on a construction site can be a potent combination. One thinks of pressing a few buttons and having one's site graded automatically. It's not quite that simple, of course, but it is easy to see why contractors would be interested in it.
The California code defines the practice of land surveying rather broadly in my opinion (but that's all right), and includes construction stakeout within its scope. Triggering the recent debate was a question whether supplying digital design data (or digital topo) to a contractor would constitute aiding and abetting an illegal act! Now we are to treat digital design as a controlled substance? The situation would be comical if the stakes for surveyors were not so high.
Whose Ox is Gored? Let's dispense with all the fluff and get right to it. This is about turf and loss of income. Period. Surveyors (and everyone else except earth-moving contractors) would ignore GPS-driven equipment if it did not mean the loss of fees for professional services. Is anyone anywhere arguing that the public is at risk here? After all, construction stakeout screw-ups are some of the fastest surveying mistakes to detect. No one discovers the inlet is in the wrong place 15 years after it was built. We have that potential with boundary issues, of course, but stakeout? I think not.
My state of Maryland has similar language about construction stakeout, which, if taken literally, would prohibit carpenters from laying out an interior wall by themselves! Of course, no one has ever paid the slightest attention to that silliness, but the inclusion of dismissable language is a Bad Thing for a statute to have, because it invites dismissal of other language that actually should be enforced.
One might inquire whether including construction stake-out within the exclusive domain of licensed surveyors is really necessary. I have been on many construction sites where the contractor has his “layout guys” onsite every day supporting the carpenters and others, and The Republic does not seem to have suffered. Can we really claim a threat to the public? If so, how is it that surveying equipment can be sold to anyone, not merely those with licenses?
The Risk and The Reward
In the last issue I opined that site designers are not forced to use any particular data as a basis for their design, and indeed could use no data at all if they saw fit. Stopping them from doing so, of course, is the probability that the design will fail when constructed, exposing them to liability from their client. This is as it should be. Designers are expected to analyze the data available, decide upon its sufficiency, and complain if it is not up to snuff. In the same manner, the contractor has an obligation to employ tools and labor sufficient to build in accordance with the plans. If he chooses to use unskilled carpenters, who end up costing him additional time and money to do things twice, he bears the extra expense. Likewise, if he chooses to invest in heavy machinery rather than employ a legion of laborers with shovels, he takes the financial risk, and is entitled to the reward. What then is the difference in his employing GPS-enabled equipment rather than hiring a survey crew? If we require him to hire the crew, despite his knowing that the alternative GPS method would better suit his operations, we have engaged in featherbedding: the practice of requiring the employment of a certain type of people even after technology has obsoleted their job. Is that where we want to be?
Opportunity
There are many aspects of construction machine control in which we should involve ourselves, including initial control setup, quality control, performance monitoring, etc. Additionally, my experience has been that digital files from many designers are not really three-dimensional files, but instead are a series of two dimensional files. In other words, the designers have used a computer like a pencil, and have not taken advantage of its potential in creating a seamless target terrain model. Obviously such a digital product would be of no use to the GPS-enabled contractor, and thus an opportunity exists to create one that the contractor can use. This will probably diminish over time as older designers die off and true three-dimensional design takes hold in civil shops. In the meantime, however, it has been the surveyors all along who have been interpreting those designs. And, as a class, we have been computer-savvy from way back. We serve as a go-between for the contractor and designer. Not by fiat, but as a natural fit.
So here is how I see it: There should not even be a hint of featherbedding surrounding our practice. (Nothing encourages cynicism on the part of our clients and allied professions faster.) When surveying skills are genuinely required, the law ought to require licensed surveyor involvement. And when they are not, the law ought to be silent. (In my opinion, construction stakeout falls outside of required surveyor involvement – there are too many examples of success, despite our non-involvement, in the marketplace.) We ought to encourage our contractor clients to convert to GPS-enabled equipment, and stand ready to assist them in the support tasks that conversion will engender. There will be work for those able to see around the corner.
Joel Leinger is a principal of S.J. Martenet & Co. in Baltimore and Associate Editor of the magazine.
A 83Kb PDF of this article is available by clicking HERE
Editorial: Machine Control Redux
I have received a fair amount of response to my July editorial about machine control. Responses included those who agree with me as to the inevitable impact it will have on the future of surveying and those who accuse me of selling out. Notwithstanding those states such as California that require a .... Read the Article
Point to Point: The Pincushion Dilemma
Pincushion corners result when two or more markers exist identifying the same property corner. If set by surveyors, they are invariably the result of different interpretations of evidence, whether justified or not. The measurati have almost universally denounced them as further evidence of rank-and.... Read the Article
The WowFactor: OfficeSync
Drastic changes in the U.S. economy, including the recent runup in the price of gasoline, have had a direct effect on how firms use technology to remain competitive. Civil engineering and land surveying firms have had to make serious decisions, and time management is ... Read the Article
In Search of Monhegan's Letters
Monhegan Plantation is an island ten miles off the coast in the Gulf of Maine. An artists' haven with a rich history in fishing, the island's average population of 75 residents explodes each summer with the opening of ... Read the Article
Towers of Power - Surveyors Locate Next Generation Transmission Lines
As originally planned, the Eastern Plains Transmission Project, one of the country's largest power expansion projects in progress, is expected to ultimately deliver about 1,000 miles of .... Read the Article
A Visit to the South Carolina Geodetic Survey
One of the hold-ups in the implementation of Real Time Networks (RTNs) for machine control has been the vertical accuracies. That being the case, when one of our writers, Joe Betit, told me that he had heard that the South Carolina .... Read the Article
In Memoriam: John E. Chance, 1924-2008
A legend within surveying circles along the Gulf of Mexico and in the petroleum and pipeline industries worldwide, John Chance died May 1, 2008 at his home in Lafayette, Louisiana. "Mr. John," as he was affectionately known by his friends, was born John Edward Chance on ... Read the Article
FeedBack
More on the Schuylkill Center Wendy Lathrop's valuable article "Where There's a Will... " [Sept. 2007] couples the Orphans' Court activities of the Barnes Foundation and the Schuylkill Center for Environmental Education (SCEE). From a legal point of view the breaking of ... Read the Article
Software Review: General CADD
Backward compatibility has always been one of the things that make a good solid product. General CADD started out as an inexpensive CADD program working in DOS. Generic CADD was the name and it made it possible for surveyors who could not afford the very... Read the Article
Survey Reports: Preparing a Survey Report - Part 4: FAQ
This is the fourth article in a series of articles suggesting formats and contents of a survey report. Previous articles dealt with opinions on the location of corners and boundaries [Feb. 2008]; encroachments, gaps and overlaps [Mar. 2008]; and limitations of of the surveying ... Read the Article
Vantage Point: Water Over the Dam and Down the River
What's old is new, and it's all wet. It may seem to be a "modern" approach to look beyond our own municipal boundaries to see what is happening on the other side of an invisible jurisdictional line that will affect flooding and stormwater on our side of that line. But awareness of ... Read the Article
• 15th Annual GeoTech - October 7-8, 2008, NOAA’s Auditorium and Science Center in Silver Spring, MD. Hosted by Potomac Region of the American Society of Photogrammetry and Remote Sensing and co-hosted by the NGS, 1 day of Workshops taught by experts, and 1 day of Technical sessions.,
• Geography in Las Vegas - March 22–27, 2009. Join 8,000 geographers, GIS specialists, and environmental scientists from around the world in Las Vegas for the very latest in research, policy, and applications in geography, sustainability, and GIScience, during the annual conference of the Association of American Geographers.
• California Land Surveyors Association 2009 Conference - March 28-April 1, 2009, Hilton San Diego Resort (Mission Bay).
This e-mail address is being protected from spam bots, you need JavaScript enabled to view it
, (707) 578-6016.
• SPAR 2009 - March 30- April 1, 2009, Hyatt Regency Hotel, Denver, Colorado. SPAR 2009 will focus on best practices for using 3D imaging technologies to design and deliver capital projects as well as operate, modify and maintain production, manufacturing and infrastructure assets.
Reach our audience of Professional land surveyors and Geo-Technology professionals with your career ad. Feel free to contact us if you need additional information.