All posts by Scott Martin

“Sea Level Datum of 1929” — Did You Know?

I recently was consulted about the use of the term “Sea Level Datum of 1929” on plans and in engineering reports dating from the 1940-60s. The inquirer was concerned that this possibly meant that the work was based on something other than the National Geodetic Vertical Datum of 1929 (NGVD 29). As is often the...

geodimeter station smith creek butte

Technology: the Bane of Surveying Traditions?

I have been surveying going on 39 years now. It’s a darn good thing I have succeeded, or at least survived in this profession, because I never really learned how to do anything else. Never really wanted to. As I have watched our profession change drastically over that time, mostly driven by technology and the...

Subsidence

Do you know where your control really is?  Editor’s note: The earth moves, even if we do not want it to – or we do not perceive that it does. If you are surveyor working in any part of the country your work will be subject to some degree of subsidence or deformation – be...