> > The question that interests me is why all the RTK work I follow is crap. Right now, I think the answer is that it gets both pushed into areas where a person wouldn't want to employ GPS at all and is used in the fastest manner possible, without any of that time-consuming checking.
>
> So all of the work you follow is crap? Or is it just the crap work that you "suspect" is RTK?
The question that interests me is why all the RTK work I follow is crap. My best guess is that the 2013 survey was done with a network rover. That explains how the survey got oriented to grid North without the surveyor apparently realizing it.
> > That is a correct description of what I see. The scale factors are seldom mentioned and the only way to determine them is to actually compute the scale parameter by transformation as I have done here.
>
> Actually, you're wrong again.
No, that's really what a surveyor has to do to figure out the sort of misadventures that RTK users are hard at work creating even at this very moment.
What interests me about the RTK messes is (a) how to identify them, (b) what causes them, and (c) whether there is any reason to think they won't continue full steam ahead. The extreme irony is that even as the technology exists to get essentially the "final answer" for most survey measurements, the folks who want to hit it all on the run are insuring that things are going in completely the wrong direction.
> > > The question that interests me is why all the RTK work I follow is crap. Right now, I think the answer is that it gets both pushed into areas where a person wouldn't want to employ GPS at all and is used in the fastest manner possible, without any of that time-consuming checking.
> >
> > So all of the work you follow is crap? Or is it just the crap work that you "suspect" is RTK?
>
> The question that interests me is why all the RTK work I follow is crap. My best guess is that the 2013 survey was done with a network rover. That explains how the survey got oriented to grid North without the surveyor apparently realizing it.
So, I'll ask it again, since it appears that you don't want to answer it. Are you sure that all of the work that you follow is good, wasn't done with RTK? Are you sure that all crap work that you follow was done with RTK? I'm aware of no way to find that out, unless the surveyor left some footprints in the description. Supposition doesn't make fact.
Also, network rovers are super sexy. They require a few extra things, like good service and not too far from the reference station, but when it's good, it's great.
I've been following a lot of RTK surveys, it has greatly increased the accuracy of data that I retrace, from BLM surveyors to private, usually I will be within a couple of seconds and .05' over a half a mile.
Often distances are reported as surface without a qualifier which I then try to match with my CSF, but it is a very, very minor issue. And I'm talking about township after township size surveys.
One of the really great things is that now the BLM surveys are super tight, something that back in the instrument and run the line days just didn't happen.
Some of the subdivisions are so close I don't even think of changing the record and when I find something "out" it usually makes me think the point has been disturbed.
Most of the issues I've seen with RTK have been on the construction side, not boundary surveying.
> Shawn and J.D. Billings set some corners we tied to in an adjoining county. Holy crap it was close. I'm not talking the magical 0.04, no. I mean I was looking in the third decimal place to find the small change.
>
> FWIW, they controlled that project with static (if I remember correctly) and we tied in their point with RTK using proven procedures. We were literally within the same dimple.
Hard to imagine that idiots in East Texas can measure to fence posts that close, Kris.
We held out a long time before adopting RTK. Today, I see it producing static quality positions when using proper procedures. As Bruce Small pointed out in another thread, it is normal to see agreement between two RTK points and a total station measurement between them agree well within 0.015' horizontal and 0.03' vertical.
Unfortunately in the history of surveying, people have abused chains and compasses and transits and theodolites and subtense bars and EDM's and total stations and levels and level rods and static GPS and most recently RTK. We, as surveyors, have the privilege of retracing it all, from the shining stars and the runny turds, and it's as the Billy Joel song goes: we didn't start the fire, it's been burning since the world's been turning.
> That would be the thread below?
>
> http://beerleg.com/index.php?mode=thread&id=289162
The very same.
> > The question that interests me is why all the RTK work I follow is crap. My best guess is that the 2013 survey was done with a network rover. That explains how the survey got oriented to grid North without the surveyor apparently realizing it.
>
> So, I'll ask it again, since it appears that you don't want to answer it. Are you sure that all of the work that you follow is good, wasn't done with RTK? Are you sure that all crap work that you follow was done with RTK?
Well, when you see offset control points and brushed lines along the traverse between them, that's usually a clue that the survey was NOT made with RTK :>
So, if one is dealing with a survey made by GPS methods, the results are poor, and the work product has some clueless features, it's almost always a safe bet that it was an RTK survey that's at the center of things.
Identifying RTK surveys
> You bring up a good point. How to verify things we see in others surveys.
> If something is unclear I do not hesistate to call the surveor and ask.
> I would think that going to a source would be a best practice for surveying, rather than pure specualtion.
Not really. The use of RTK can be easily deduced from (a) the positions of the more GPSable points being more accurately determined, (b) the positions of more obstructed points (as partially under tree canopy) being worse, and (c) a few submeter shots being mixed in at stations where nobody would attempt to use GPS.
It was the three wild shots with two to three foot errors that led me to study the whole thing more carefully to see what had actually been done last year. As a rule, one will not hear more than a funny story from the responsible surveyor when things are this messed up. It's usually more of a pattern of practice than a unique situation. I've already heard most of the stories over the years and am not writing a book.
I am interested in how future surveyors will identify and deal with the enormous FUBARS that similar use of RTK is leaving to posterity. Probably a small book of case studies of RTK FUBARS would be useful.
a: the 2003 data is screwed up
b: the 2013 data is screwed up
c: both data sets are screwed up
d: both data sets are OK, and Kent is screwed up
e: insufficient information for a Professional Opinion.
I'd pick 'e.'
Kent...if you can't afford the modern equipment used by your peers, maybe you should just get over it, and stop knocking yourself out trying to discredit a very useful tool, just because some folks may (or may not) be using it improperly.
I have found RTK “repeats” spread over days, weeks, months, YEARS (even a decade or more), in the +/- 0.03 feet (or better) range, to be the norm! Repeats exceeding 2 cm. (0.06 ft.) are quite rare.
Dufus & Goofus have been surveying since day 1, and their descendents are still with us (and always will be). Don't blame the tool for misadventures caused by incompetence on the part of the operators.
Loyal
>
> Dufus & Goofus have been surveying since day 1, and their descendents are still with us (and always will be). Don't blame the tool for misadventures caused by incompetence on the part of the operators.
Yeah, but now Dufus & Goofus all have RTK. I don't make this stuff up. It isn't exactly a trivial problem to sort out these messes and it isn't an exaggeration to say that they have become the accepted standard of practice in the great speed-up of the 21st century. The tool now finds the fool.
Dufus and Goofus are here and they are many more than anyone may know.
I know people that are very RTK trendy and have great horse sense on the subject and use and I have also seen those near the other end of the beast that should be forbidden use of RTK and some probably forbidden to be near surveying in general.
The tool does not make the person a surveyor.
0.02
Just for fun
> But just for fun, what if said [evil tool] was put on trial?
The question in that case appears to be does the technology as put into practice by the average user represent an improvement or a giant step backwards? The funny thing about the RTK disasters is they usually approach being bad GIS cartooning more than a survey of anything. What particularly impressed me about Survey No. 2 were the wild shots, the monuments that were mislocated by two and three feet. Both were in spots where no careful surveyor would use GPS in the first place, but apparently the RTK rover was producing a number of some sort, so there it went and on a run.
Identifying RTK surveys
> I am interested in how future surveyors will identify and deal with the enormous FUBARS that similar use of RTK is leaving to posterity. Probably a small book of case studies of RTK FUBARS would be useful.
That is an excellent idea Kent! We all know; that with proper procedure, RTK can be used to provide reliable data. A man like you, teaching this to future surveyors will be a huge boost to the profession.
Thank you for stepping up and taking on a responsibility like this. I am sure I speak for every other surveyor out there, when I say; we sure do appreciate everything you do.
Best Regards,
Douglas Casement, PLS
Identifying RTK surveys
Just for fun
> Now that this is continuing as just fun and entertainment; I'd have to say that I'd probably harbor the same kind of hunch you indicate, but would verify. What I find terribly entertaining about these threads is the speculation: The "appears", "apparently", etc...
I don't know what world you survey in, but an important part of land surveying work in Texas involves logical inference and deductive reasoning.
In the case of Survey No. 2, the only plausible way that such an otherwise low-grade piece of work ended up oriented within a few seconds of grid North of the Texas Coordinate System of 1983 is if GPS had been used. None of the conveyances in any of the chains of title to any of the surrounding properties contained a record of a modern resurvey oriented to grid North.
So, what is the logical means by which grid North was obtained, apparently without the knowledge of the responsible surveyor since no mention of a bearing basis is found in any of the products? Did you say "network RTK with canned projections?" Yes, that is pretty much the only possibility.
The survey was made by one of the quickie-dickie operations, so nothing is at all reasonable other than quickie-dickie RTK.
These are pretty obvious deductions from the information I provided in the original post.
Identifying RTK surveys
> > I am interested in how future surveyors will identify and deal with the enormous FUBARS that similar use of RTK is leaving to posterity. Probably a small book of case studies of RTK FUBARS would be useful.
>
> That is an excellent idea Kent!
Yes, I thought so, too. A couple of other surveyors and I are working on a book of case studies dealing with more advanced topics, but it probably would be good to autopsy a couple of RTK messes for comic relief, as a sort of counter point to discussing the types of errors encountered in compass and chain and transit and tape surveys.
Just for fun
> > I don't know what world you survey in
>
> The one where verification trumps speculation
In the context of a quickie-dickie operation, can you think of any alternate means of accomplishing what was done with the results described other than via RTK? I rest my case, thank you.
Just for fun
> You may be right, you could be wrong. A call would solve.
I'm afraid you have a very naive outlook on things if you think that a quickie-dickie survey outfit is going to give you a truthful answer when you are the guy who has found some major problems with the work which extend well beyond the RTK FUBARs which are mostly symptoms. Been there and done that many times.
No, what you'll hear will be one of at least ten different variations, all of which are obvious BS. So, land surveyors are allowed to use their reasoning ability. I personally encourage it.
The reality is that the entire operation is built on the same shoddy practices that produced the one I'm dealing with. It absolutely isn't an outlier. It is everyday RTK in the quickie-dickie, two-day turnaround marketplace.
Just for fun
Hey, it's your state that gives them a license! I don't think the real problem is RTK, it's the operators.
Just for fun
> I don't think the real problem is RTK, it's the operators.
No, it's the whole marketing push to present RTK as some sort of superduper solution. The quickie-dickie surveyors typically aren't that bright and tend to just go with the flow. When your selling point is a two-day turnaround, all sorts of other stuff falls by the wayside, too. The RTK issues are just symptoms of a larger problem.
