> 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!
So, considering that the control points you'll be setting up on will probably get destroyed in the course of construction, how are you going to document what you laid out if you don't have a check survey that shows what the coordinates of the control points were as provided to you?
I'm a land surveyor and I thought that contractors were actually concerned about these sorts of issues that can really bit a contractor in the wallet.
Surveyors don't seem to know what are datum, datum tags and epochs.
OPUS NAD83(2011) epoch 2010.00, Geoid 2012A won't match NAD83(HARN), epoch 1993, local benchmark control, of course?
SOP on any projects I work on....
Would be to set additional control out of the way of construction from the existing control before it gets torn out. Most of the staking I do ends up being by robot so usually I set the additional control with the robot.
SOP on any projects I work on....
> Would be to set additional control out of the way of construction from the existing control before it gets torn out. Most of the staking I do ends up being by robot so usually I set the additional control with the robot.
Well, you still need to document the control as you found it, right? If there's a problem, it's a safe bet that whoever surveyed the control (that now is no longer in existence) will be swearing up and down it was "right on the money").
My view is that the whole operation is a bit like any other construction operation where some previous work has established some site condition that later work is to build upon, except trickier considering that much of the evidence of the control survey will disappear.
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.
BTW, Dave Karoly's post reminds me that I've been using shorthand to describe geodetic coordinates that refer to NAD83(2011)Epoch 2010.0 and NAD83(HARN or CORS96)Epoch 1993.0.
> 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.
Actually, was it specified in the contract that no checking of the DOT control network would be permitted? That's certainly a new one! You've got to pity any contractor who takes that one on.
SOP on any projects I work on....
Washington State has a requirement and forms that need to be approved before monuments are destroyed. The argument is over the verification of the controls in the beginning of the assignment and the verifiability of the deliverables. It's Metadata, always budgeted.
> So, considering that the control points you'll be setting up on will probably get destroyed in the course of construction, how are you going to document what you laid out if you don't have a check survey that shows what the coordinates of the control points were as provided to you?
>
> I'm a land surveyor and I thought that contractors were actually concerned about these sorts of issues that can really bit a contractor in the wallet.
1. It's highly unlikely that 10 miles of control will be destroyed.
2. All projects I've worked on the surveyor had the wisdom to put control outside the Limits Of Work, we clearly stake and flag them (the CPs) and threaten bodily harm to anyone who disturbs them. (So yes, we are really concerned)
3. In the 'unlikely' event that so much control is wiped out that it needs to be re-established, well ........ that's when I call my surveyor back in.
Even I can set a temporary hub and re-establish a point from the file given for a project, or from the point file I have established by checking the physical control. If I am already localized and can repeat 3 or 4 CPs in that general area, my confidence is high.
Kent, everyone works differently and, at some point we have to stop surveying and start the 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.
Mr. Cow, I like that!
The contract clearly states that you will go to the field, occupy the control using the native system provided and check monuments using that system. This is an important task because they want to know if this system will work for any surveyor who may need to use it as is.
They don't want to relate it to another EPOCH of state plane, they want to know if it is good internally, are the monuments still in the ground and have any been destroyed or disturbed.
That way anyone walking onto the job will be able to use this control as is with confidence. They do not want you to do some jacked up translation to OPUS or CORS.
It's very important that the control is used as it because this control is given out to all the contractors and is expressed on all the Plats and Maps for the job.
The coordinates and elevations, Lat and Longs are FIXED positions and it's your job when starting the work to check the control and be sure it works in its native format.
A job you will clearly not do. You are going to jack around with OPUS creating a translation they do not want you to do. If you can't check this control in its native format, please don't do the work. It's clearly not something you should or are able to do. I can't stress this enough, they have no interest in OPUS for this task, they have put a lot of time and money providing a gold plated adjusted static control network for everyone to use, and they need to know that it's still in good condition and is ready to go as it's given out. PERIOD!
Kent...
>
> The OP was ambiguous ....
only if you're a moron.
Kent...
This lengthy thread is a good example of a key problem in our industry.
A competent surveyor placed in area where he does not belong and creates costly problems to clients non-surveyors who do not know any better. That kind of non-professional behaviour should be ground for license suspension or revocation.
Guys, this is not rocket science. Here's the control, work with it. Check it, expand from it if need be, but work with it.
This is construction surveying 101.
Less talking and more staking.
If the DOT knows this as well as you say, (and I'm not doubting that), why are they even entertaining this surveyors line of thought??
They have the original passive data, they have your checks, WHY aren't they dismissing his "control is bad" commentary out of hand?
What we have hee-yah....
Is failure to communicate...
> Well, you still need to document the control as you found it, right? If there's a problem, it's a safe bet that whoever surveyed the control (that now is no longer in existence) will be swearing up and down it was "right on the money").
This, apparently, is a teamed project with the various members of the team having their own obligations and responsibilities, together with the right to assume that other members of the team have performed their work correctly - until proven otherwise. So the staking surveyor is obligated to ensure that the control he is using is correct relative to other control in the network - in the manner of ensuring that he has found the right monuments and they have not been molested - but not to rerun the entire network, nor to quibble over reasonable residuals. If, in so doing, he should find some significant irregularity, his obligation would be to alert project management and initiate a resolution before proceeding.
Consider what the case would be if the control was based on assumed 5000,5000 and a compass bearing. The staking surveyor would not need to make checks to any control outside of the project limits. There would be no question of checking to OPUS.
The staking surveyor does have a obligations to document his work relative to the established project control. The control surveyor is obligated to ensure that that control is correct, and that the network has sufficient remote ties to permanent monuments to ensure restorability. Monumentless surveying is a myth so long as NGS continues to readjust every few years.
These "modified state plane" systems are bastardizations - no argument. But they are, and have been, DOT policy in many states. If you want to work in the DOT world you have to deal with them. That's our cross to bear.
If someone proposes to establish NAD83(2011) control to a project that was designed based on NAD83(93) that will have the effect of shifting the designed improvements, unless you propose to shift the entire design also. Which would ripple through the entire design team and confuse any redesign or updates. No, there are better ways to deal with this.
Checking control before use is completely appropriate. Running an OPUS and declaring a network invalid based on a raw comparison is not.
Are the NAD83 1993 coordinates grid?
Kent...
> >
> > The OP was ambiguous ....
>
> only if you're a moron.
Well, since it definitely would be possible to identify significant errors in a project control network of the sort described using OPUS solutions, that means that there are at least two possible scenarios described in the OP. MM didn't say that the project surveyor's opinion was based on just one OPUS solution.
> Are the NAD83 1993 coordinates grid?
No, MM posted that they are bastardized DOT coordinates that have been scaled, apparently still resembling SPCS values.
What we have hee-yah....
> If someone proposes to establish NAD83(2011) control to a project that was designed based on NAD83(93) that will have the effect of shifting the designed improvements, unless you propose to shift the entire design also. Which would ripple through the entire design team and confuse any redesign or updates. No, there are better ways to deal with this.
>
> Checking control before use is completely appropriate. Running an OPUS and declaring a network invalid based on a raw comparison is not.
If you're suggesting that any competent surveyor shouldn't actually set his instrument on the actual control monuments, I'm afraid surveying must not be the same North of the Red River as in Texas. :>
Sorry, felt like Kent for a minute there. You're dead on Norman, as usual. It's hard to understand why this is so hard to understand.
> > Are the NAD83 1993 coordinates grid?
>
> No, MM posted that they are bastardized DOT coordinates that have been scaled, apparently still resembling SPCS values.
Your reading comprehension is hilariously frustrating or frustratingly hilarious.
For the reading impaired (from above):
DOT sends out control spread sheets with: state plane coordinates, surface coordinates, ellipsoid heights, geoid heights, latitudes, longitudes, the state plane zone and that its NAD83 and in this case 1993 EPOCH, included is the combined adjustment factor and how it should be applied. On the sheets are shown how the control was derived, static, fast static, RTK, leveled, and so on for each point. Also they show the computer program that ran the adjustments the HARN points used to adjust to control, their values at the time of adjustment and more than that, but you really don't need more. It's all there! Really this is so easy, why do surveyors fight it? I don't understand!
Kent...
> >
> > The OP was ambiguous ....
>
> only if you're a moron.
or maybe work for a DOT.:-) Two way high way.
I found the OP to be sketchy to say the least..
It wasn't until the next day that the scope of work and some of the historic method of the established control was presented.
It is apparent that the construction surveyor tried to verify the existing control.
Basic procedure for any project and to cover his E&O buttski.
It looks like that he did not follow due diligence in the field by replicating the methods of the control checks.
Solely using OPUS was a quick and dirty way to establish SPC. But OPUS was a way for him to get to the point of translating the work to the established datum. But he should of tied to the previous metadata.
Others here, have used the worn out and trite alliterative platitude of " following the footsteps" ( please take note of the triple redundancy)but if you can not use modern technology and applications to " follow the footsteps" maybe you need to be gently laid to rest instead of the slow and painful death referenced in a previous post.
Point being that a more descriptive opening post describing more of the history of the project would have prevented the caterwauling and the "nah nana na nah your a moron" comments.
Not very professional even though your state job title may state that you one.
Yes, if the client is stating that the control is good to go, you must respect that ....in writing of course and signed off by each party of interest. But I always feel that it is an obligation to check that control for the client's benefit. [sarcasm]If you don't you are operating as some type of 9-5 employee ( maybe with flex hours) and not as a a professional.[/sarcasm]
