Many years ago, and probably during the day of one-second total stations, I happened upon a survey plat with bearings in degrees, minutes, and seconds out to TWO decimal places! :-O
I wondered if it was the CAD guy's fault or the PLS. But the PLS signed it......
While at surveyor's conventions, I have seen example survey plats from all over the nation. At one particular plat, a group of us were marveling at the "close-ups" of the discs in a 6"X6" concrete monument showing a new dimple at some minuscule distance away from a found dimple.
I agree with an above post. I believe that the same surveyor would get different results on the same survey when done again.
We wondered, "how close is close enough"? My, how we can measure!
Both using RTK
It could be worse. In CA, in San Diego I was told to change my street dimension between 2 monuments by 0.01' by a CA L.L.S. city surveyor. The reason..."according to California Street and Highway code the public is entitled only to it's full record r/w width" i.e. 100.00' instead of 100.01'. Got me wondering if I should pull out my dimpler... Go figure...CA is a much different survey world than anywhere else. 😀
Pablo B-)
I admit I've done the same.
An example:
I did a survey, that place was seriously moving. Really weird, wet, very sticky, very heavy clay. There were slip outs throughout the hillside.
Retracing a 1920s subdivision boundary, I found good evidence of the west end of the line (the original monument is gone but there were plenty of nearby references that fit together very well). This is at the bottom of the hill in stable ground. I found a rusty iron pipe with wooden plug to the east several hundred feet in relatively stable ground which I took to be one of the "iron pipe monument"s shown on the old Map and several other surveys did too. There were a bunch of intermediate pipes, rebars, nails and tags set in block walls along the line set on Corner Records over the years using various other non-original monuments and various methodologies. They fit pretty well considering the variation in methods and the movement present. I just stationed/offsetted them from the line for ease. The small differences don't really matter to anyone but surveyors.
Our monuments move more than most of us think especially in clay soils.
That would have been a good thread on it's own right there! 😉
Both using RTK
But wouldn't 100.01' still be the full width?:-)
Both using RTK
> I maintain that it is unprofessional to blanket an entire technology that is standard in the profession, proven in its use, and valuable to our clients.
I'm sure that all RTK users aren't unaware of the sort of discrepancies that would be normal and expected when you check positions with +/-2cm uncertainty by a method with +/-2cm uncertainty. Why would a person want to pretend that the discrepancies shown in the example would not be typical?
Both using RTK
Showing a 100' wide road R/W as 100.01' is very similar to calling a monument .01' off line isn't it? Just saying.
I can't count the times I've had to explain that I certify to the facts that were found on the specific date of my visit to the property.
What happens and what is out there today may or may not be the same.
My most recent adventure was retracing 10 acres inside of a subdivision I created in 1984. All monuments gone and plenty of surrounding monuments and control in place.
I took off from my control hubs and ran down a new pipeline and ended up tying into three monuments at a highway.
One monument was some 4 feet out from where it was originally. I was surprised it was there considering a new pipeline was laid on each side of it. Honestly, it looked like it had been scooped out of the ground and plopped down somewhere close.
😉
Both using... allegations
> It's not the tools, it's the fools.
:good: :good: :good:
Both using... allegations
> It would be nice if the allegations of something wrong-due-to-this-or-that was actually backed up by peresentable proof of such an allegation.
This was just pointing out the obvious fact that if you check a position with a 2cm uncertainty by a method that itself has a 2cm uncertainty, the likelihood of the results exactly matching is very small. The expected "miss" is in fact more than 2cm.
This was demonstrated in a thread perhaps a year ago or so that I believe you probably read since you posted to it.
I was taught that in the case of found, original monuments by the creating surveyor, there is no error.
Both using RTK
Right of Way is indeed a horse of a different color, in that, generally, monuments do not control the width. So a ROW that is 100' wide by statute is not, say, 105' wide even if all the original monuments are set 105' wide for miles along the route.
That's not my drawing, but I have probably committed similar surveying crimes and cringe at the thought of my incompetence being brought forth as an example of how far the profession has fallen. As a young surveyor, I'll be the first to admit I haven't quite figured out how to handle how things are vs. how things should be (according to record).
For one of the first boundaries I worked on, I connected the dots from monument to monument (and annotated them as such) on a section line with an overall bearing and distance shown between the controlling corners. In my mind, I was just showing things as they were in the real world, not as they should have been per the record plat. The surveyor in responsible charge told me to change it and only show one bearing with distances in between the monuments. Once that box was opened, I've hard a hard time shutting it.
And now I'm into r/w, it's even more confusing as to how I go about giving the deeded R/W widths (no more, no less) to the govt and maintaining the record (especially tangency in curves!) while trying to honor the monuments, which never agree with each other in a purely mathematical sense if I have 3 or more.
Are there any heuristics in surveying to help a young idiot surveyor deal with how things are vs. how they should be? I'm looking for something better than "the monuments control." Maybe like a book that all the sanctimonious guys who have it all figured out agree on? Or maybe I should just stick with construction and control, where the math is clean and tidy.
Both using RTK
Mighty,
I should have added to that quote as "no more no less".:-P
Pablo B-)
One thing to realize is that the full width does not always control:-)
In fact it often does not
ain't it interesting how the same guys who harp on numbers don't control also seem to lecture us on how imprecise our numbers are?
The first book I'd recommend is "The Pin Cushion Effect" by Lucas.
Stephen Calder, PLS (yes, he frequents this board) wrote a very good paper about right of way surveying. Do a search, if you can't find it, contact Mr. Calder. It is called "True Confessions of a Right-of-way Surveyor".
Both using... allegations
> Two years ago and as always good food for thought, no part of which actually proves that parties in this situation were "both using RTK".
What I posted above was "Actually, those sorts of errors look very typical of RTK x 2, i.e. monument positions determined by RTK "checked" by RTK."
Are you disputing the premise? If so, what has changed in now two years to alter the underlying facts of the random errors inherent in RTK?
Some of you expert measurers seriously make me laugh while scaring the he!! outta me, 0.01', we just wasted the 0.04 argument.