Again totally incorrect. Cant be more wrong.
Shawn, I really don't see how introducing new OPUS values could be useful. It would only add a layer of numbers that would be confusing and no doubt DOT would be agaisnt it and have already considered it and rejected the idea. This really isn't difficult. Set on the control using the values and projection given to you and survey. Simple. If you can't or won't, then don't do the work. And you don't need GPS to work on one of these projects an instrument will do just fine. Slow but fine
> Again totally incorrect. Cant be more wrong.
So, it sounds as if you're disputing the idea that, all other things being equal, a GPS vector surveyed from some point of latitude, longitude and ellipsoid height with a known relation to IGS08 will be of higher quality than one from an erroneous latitude, longitude and ellipsoid height of unknown relation to IGS08. Do I have that right?
> Shawn, I really don't see how introducing new OPUS values could be useful. It would only add a layer of numbers that would be confusing and no doubt DOT would be agaisnt it and have already considered it and rejected the idea.
"No checking or verification of project control shall be conducted by the contractor." Somehow, I'm not seeing that one as catching on. :>
> Again this is adjusted static control with elevations values run with levels. It's not unkown and if you start OPUSing it you are introducing values inconsistent with the passive network that created it. It would be unprofessional to use OUPS and some weird translations. You already implied that you wont reoccupy the passive network control, which would be an extream thing to do, but would at least be surveying in the system that created the points.
Okay, so now your idea is that to properly check this DOT project control, you need to begin on the nearest monument with an NAD83(1993) position published in the NGS data base? And why wouldn't just surveying it all in NAD83(2011) and solving the transformation to the project system not be quicker and better?
Dammit, Kent! MM has told you again and again that the control is perfect and doesn't need to be checked. That surveyor should just STFU and stake the damn road. My only question is, why did they hire a surveyor? All they need is an instrument operator and a hub pounder. Get hot, boys!
Dave
> So, the way that you check the project control is to use a method that accurately determines the relative positions of all the points, dN, dE, and dUp.
>
I'm just a dumb contractor, but..... the control WAS established. All the contractor has to do is set up his base on a control point with given data, reference his rover to other control points where necessary, and he is good to go!
The (as I understand it) need to resurvey 10 miles of a project was not required or requested. If the DOT, in this case, has signed off on the existing control all you really need to worry about is something that may have been destroyed or obviously screwed up.
No I am not a surveyor nor do I hold a license of any sort, I have a surveyor check my control to make sure that what I'm doing makes sense. I may check to a known monument to verify in my little head that the control is was it is supposed to be. I wouldn't give a rats a$$ about OPUS or anything else in this situation.
I realize that this is a surveyor forum, and Kent you like to survey the hell out of things, but it simply is not required here, IMO. I believe there is way too much over thinking on this 'simple' problem.
You and Kent share the same problem of not reading and distortion. MM never said there should be no checks.
> You and Kent share the same problem of not reading and distortion. MM never said there should be no checks.
He pretty much is against doing a more accurate survey of the control network than the one that produced the values if he doesn't want a surveyor using accurate NAD83 latitudes, longitudes, and ellipsoid heights. It's sort of like someone who laid out project control with a transit and tape insisting that checking it with a total station will really mess things up. :>
My bad, Shawn! OK, limited checking, no OPUS, no boat-rocking, and don't offend any of the keyboard surveyors!
How's that?
Dave
The bottom line is to meet the contract specs
It doesn't really matter how you do things when you are starting from scratch, but, it matters a whole lot when you need to follow someone else's footsteps.
If someone wants to label a key benchmark near the center of the project as 100.00, run with it. All that matters is the amount higher or lower than that benchmark needs to agree, even if you think the TRUE elevation is 1234.56 instead of 100.00.
The same applies to the horizontal situation. If they want to call what you view as North 14 degrees East as North, you need to rotate your work to match theirs.
Insisting that any prior work is wrong simply because it doesn't fit with your preferred system is overly arrogant and encourages others to hope that you die an early, painful death so that you will no longer be a problem.
By this whole arguement you seem to be agreeing with the surveyor that the control is "unusable" because it didnt match his OPUS solutions, not because it didn't match design. Sounds to me like he's not at all against checking any way they want, but they damn well better use the control provided (which apparently has been checked and is correct as it pertains to this project) that was used to create the centerline and everything else associated with it. That right there makes it usable. What if the control was off 100' from his solutions but was used for design and prior construction. Do you still think its unusable? I had that exact situation on a road job straightening out an S curve, didn't even know it until the job was almost finished, because I couldnt use GPS on it until then. It tied in perfectly at each end.
> By this whole arguement you seem to be agreeing with the surveyor that the control is "unusable" because it didnt match his OPUS solutions, not because it didn't match design. Sounds to me like he's not at all against checking any way they want [...]
No, the subject of this thread is "How to Efficiently Check Project Control in a Highway Corridor approximately Ten Miles in Length". OPUS is an obvious part of that even though MM can't get his head around the idea that accurate NAD83(2011) coordinates can provide an excellent check on the quality of NAD83(1993) coordinates.
I'm pretty sure that MM is dead set on the idea that the whole job will collapse in a pile of smoking rubble if any OPUS solutions are used in the process of checking the project control. Who knows what the real story is there?
No, the subject of this thread is "How to Efficiently Check Project Control in a Highway Corridor approximately Ten Miles in Length"
I think you better start another thread if you want that to be the subject of the thread. This one would be more like "How NOT to determine if the control provided is unusable on a highway project".
The bottom line is to meet the contract specs
>
> Insisting that any prior work is wrong simply because it doesn't fit with your preferred system is overly arrogant and encourages others to hope that you die an early, painful death so that you will no longer be a problem.
:good:
Kent...
According to the original post, was there any conflict or errors in the control that was established as it related to the other control points, or to the project?
> No, the subject of this thread is "How to Efficiently Check Project Control in a Highway Corridor approximately Ten Miles in Length"
>
>
> I think you better start another thread if you want that to be the subject of the thread. This one would be more like "How NOT to determine if the control provided is unusable on a highway project".
Well, the proposition was forwarded that you couldn't determine via OPUS solutions delivering NAD83(2011) coordinates whether some control network surveyed in NAD83(1993) had some major problems. That was obviously wrong.
The further proposition was set up that OPUS would in fact be completely useless for checking a control network in some bastardized projection based on NAD83(1993). That was obviously wrong.
Kent...
> According to the original post, was there any conflict or errors in the control that was established as it related to the other control points, or to the project?
The OP was ambiguous in that alternate interpretations were possible. The poster made further clarifications of the OP in which he identified the use of NAD83(2011) coordinates obtained via OPUS in a survey to verify a control network surveyed in some bastardized coordinate system based on NAD83(1993) as unimaginable, or something to that effect.
It was hardly unimaginable and is in fact very good practice. That was the point of departure for the real discussion which amounted to how to verify a funky project control network.
The bottom line is that you would refuse to honor your contract and work in the system and control provided; not sure why but..........oh well. Maybe you don't have the knowledge or experience.....it sounds that way. Again they aren't asking you to use the provided control, they demand that you do. If you're incapable of doing that, then this isn't something for you.
The bottom line is to meet the contract specs
> If someone wants to label a key benchmark near the center of the project as 100.00, run with it. All that matters is the amount higher or lower than that benchmark needs to agree, even if you think the TRUE elevation is 1234.56 instead of 100.00.
>
> The same applies to the horizontal situation. If they want to call what you view as North 14 degrees East as North, you need to rotate your work to match theirs.
>
Well, the question still stands as to how to best check even a jacked project control network of the sort you describe and the answer is still the same, i.e. if you're using GPS, survey it in NAD83(2011)Epoch 2010.0 and compute the transformation that relates the real world coordinates to the jacket project coordinates. For a highway project about 10 miles in length, OPUS is a very efficient way to get NAD83(2011)Epoch 2010.0.
The problem with saying that construction surveying is "following someone's footsteps" is that the project control will probably mostly get destroyed in the course of the project and you don't want to use a checking method that depends upon the continued existed of the soon-to-be-destroyed control monuments to prove that you actually laid things out according to plans.
