With the growth of automated machine guidance increasing at a strong pace, related work occurs in surveying, stakeout and data prep. Machine control is useless without a good 3D model, and we have talked about this in my writings for over 10 years! I wonder if the field of support services for machine control hasn’t matured to extent where we need the law to catch up to it.

I wrote about states requiring licensure for those preparing data prep models several years ago, and I have been watching reactions to these directives since they are not laws, per se; rather, they are edicts handed down by the state boards of engineers and surveyors. This technology is now at least 10 years old, and legislation has made some attempts to hold licensed people accountable for the poor results that machine control can produce.

I think a process should be developed where the survey license is augmented by an educated and skilled level of survey personnel who will specialize in model building. The surveying community is a natural choice for this since they traditionally perform stakeout functions and this is simply digital stakeout. Capture this market before you lose it!

There are many facets to data prep for AMG and a license would at least guarantee that a minimal amount of awareness and a lot of accountability would be embedded into the use of this technology.

A large percentage of poor results are caused by the preparation of bad models and we have numerous examples of these. Here is a short list of reasons why models go bad:

  • Not understanding the machine control technology and how its existence relies on good 3D data
  • Not understanding that a machine will build a bad model very accurately
  • Not understanding the tools of the trade in building a 3D CADD model
  • Not having the right training in model building
  • Not understanding how to QA/QC a 3D model
  • Not understanding how to customize a 3D model to the machinery that is slated to construct the site
  • Not understanding that building models from contours is  usually NOT the way to accomplish it
  • Not understanding that the engineers data often has to be completely rebuilt by the surveyor
  • Not understanding that the model is the critical component to machine control construction
  • Not understanding that the model needs to be disseminated to the field and must be broken up with logic and forethought
  • Not understanding that the model building must take into account the skill levels of the operators
  • Not understanding the potentials and pitfalls of the Delaunay triangulation method
  • Not understanding that processing TIN data in a CADD system will be different than processing it in the machine control manufacturer’s software
  • Not understanding the grading tools within your software and the ramifications those tools have on the objects.
  • Not understanding that there are often multiple models required to serve a site
  • Not understanding that multiple models need to emanate from the same source
  • Models depicting the various strata of the same feature, for example, the sub –base, the base, the finished surface, the surface for curb and gutter, all need to be part of the same model


Again, I think the industry of AMG has matured to the point where we need people licensed in the art because there are way too many lawsuits and problems. I know one state engineer’s board who is contemplating a side license just for data prep, and I thought that perhaps the surveying community should step up and beat them to the punch.

Engineers generally should not be preparing data prep models; surveyors should. So, do we need a certificate in data prep attached to the survey license?

Image: A 3D TIN model.