I could see the fumes

wow. OPUS is good. Great actually. Starting a new project I would very likely begin the control with OPUS unless there were reasons to use something else (which can certainly be the case).

Picking up on an existing job with an existing control network, with points that are within acceptable relative tolerance to one another and creating a new control network? wow.

This is a typical DOT project, they went through in the late 90's early 2000's placing control with 3" aluminum caps set into concrete (NAD83/93 tied into local HARN) every 1500' or so. They ran levels along the route tied to a first order bench mark system, then laid out targets and mapped the route. The upgrade project waits until funding becomes available, they call us and we do a set of ROW plats, checking control (has any been disturbed, do we see any problems) and in this case setting 69 new monuments and cleaning up any issues with the ROW, then the design is done and if widening is necessary some new land is purchased.

After all that the construction is bid and they start the project, all the surveyor needs to do at that point is set on the control-yes typical DOT-NAD83 State Plane with a scale factor to bring it to surface-easy!

OPUS should have never even been looked at let alone changing the topo, design, ROW plats, legals, engineering designs to match a beyond silly surveyors idea of some insane perfect OPUS world. If you can't survey to that control system-get out of the business, it's embarrassing, and I'm seeing more of it.

> This guy went out and declared all the control unusable, the control we just got done checking which was all good.
>
> So I ask what's wrong with the control?
>
> Nothing, he says, this guy went out and started to run static OPUS on it and it didn't match.

You certainly can't fault the surveyor for checking all the control points to be used for layout as the first operation before commencing work. That's commendable.

Was the only issue that there was a constant offset in horizontal coordinates across the project when new OPUS-derived NAD83 positions were compared with the project values, or was there some other supposed geometric problem with the control?

same way here. if you have an abundance of existing control (as we do in HARN) it doesn't make a lot of sense to rock the boat with something new, just because it's new. if you just really want to, tie in some of those points to OPUS so you have an offset for your own records.

no existing control, or the existing control is sketchy? OPUS starts making a lot of sense.

OGRA Special Provision

Here's a link on the general theme of survey monumentation that may assist explaining to "The Unknowing" why it cost so much post construction to reconstitute boundaries if inventorying of monumentation does not happen:

http://www.ogra.org/Portals/0/Special%20Provision%20Survey%20Monumentation.pdf

Cheers,

Derek

Of course I can, he didn't check it!! OPUS isn't a check, he has to actually survey that isn't surveying

OGRA Special Provision

Yes, it's very important to follow through with control and property monuments, this project will no doubt remove much of the control, they should leave the ROW monuments we set, that was a lot of work!!!!

:good:

OGRA Special Provision

Good thing he didn't have a set of vice grips and a dimpler!!:-P

Pablo B-)

OGRA Special Provision

or a big sledge, knock the monument over so it matches OPUS, then jack it up or hammer it down the 6" it's off the vertical. That should fix it-get them on OPUS numbers!!!!;-)

Maybe when one creates a control network of points, they should do all of the preliminary work, then convert it down to a dummy-set of coordinates using 40,000/20,000 as a base. Then the OPUS boys can come in and reconvert their work down to the same controlling points and see how they match. 😉

OGRA Special Provision

Reviewing a boundary survey today where there were 15" difference in Record and Measured bearing between two mon's 50' apart. Should I tell him he hit the wrong edge of the dimple! :-O

Pablo B-)

They have quite a data-base and are completely aware of how it relates to CORS, I looked at when we set-up on them and didn't really care-just for my own interest.

But they do control using their own methods, they take state plane coordinates and multiply it to get to ground.

We could argue that all day long, but that's how they do it, and most of it is based on NAD83/93. And because they started GPSing everything back in the 80's CORS and OPUS aren't in most of the projects.

And they level everything, so the Geoid numbers are often not very close, they tend to get worse from the first order bench marks over time, they kind of move up around here.

OGRA Special Provision

If he accepted the monuments instead of making a virtual or actual pincushion, then don't knock it.

OGRA Special Provision

That's funny!!

OGRA Special Provision

> If he accepted the monuments instead of making a virtual or actual pincushion, then don't knock it.

It sounds like the 15 seconds WOULD create a virtual gap at least. Things like that bother me to no end.

Carl

> Of course I can, he didn't check it!! OPUS isn't a check, he has to actually survey that isn't surveying

Well, possibly I misunderstood what you posted:

> ... this guy went out and started to run static OPUS on it and it didn't match.

What I got from that is that the project surveyor got OPUS-derived positions on a few control points and discovered some significant misfit between the coordinate values provided and the NAD83 coordinates of the points.

I would myself never stake out construction without checking all the actual positions of the control against their supposed values, so the other surveyor positioning several of your control points to begin with seems perfectly reasonable. In fact, anything less seems a bit shaky.

Mighty-M,
I was being a bit sarcastic. Once you have a local coordinate base, you can get there with OPUS or EDM measuring systems, or other means. It doesn't matter. You don't need to redo the whole job and make new coordinates. You don't have to do anything beyond making enough checks to make sure there aren't any blunders in the provided control.

What I got from that is that the project surveyor got OPUS-derived positions on a few control points and discovered some significant misfit between the coordinate values provided and the NAD83 coordinates of the points.

I would myself never stake out construction without checking all the actual positions of the control against their supposed values, so the other surveyor positioning several of your control points to begin with seems perfectly reasonable. In fact, anything less seems a bit shaky.

I have no clue what you're talking about, OPUS has nothing to do with the project control. The project control was set using local HARN control (NAD83, 1993 EPOCH), which by the way is clearly stated on the documents given to everyone; if he wanted to check to the HARN, then he should have occupied the HARN monuments and ran static to the project control monuments (but that would have been work-since they vary from 30-70 miles from the project) using the given coordinates of the HARN monuments. But he didn't do that, he ran an OPUS solution, of course it didn't check, how could it? From what I noticed it's about .25' horizontal and .6' vertical, in other words it's junk. Pointless and completely useless. The DOT knows that, I knew it wasn't going to check to OPUS, anyone that's a surveyor should know that. But internally the control is very tight .02'-.04' is all we saw and that's what matters. Because, and this is very important, all the topo, design and legal descriptions for ROW was done from that control system.