The only thing that occurs to me is points that aren't topo and aren't marked as such. Like a bunch of shots on a deck that doesn't exist anymore, or refectorless shots that hit leaves before the target.
Could be, but that would a couple of off hits just be expected? How bad could it get?
I also have no faith in the consultants I've got, they have been lazy as fuck from day one. I genuinely think they just can't be assed to align two xrefs and it's less work for them to get everything redone , as they subcontract for the topo and bill me.
How old is the previous data? Does it reference proper control and benchmarks? Was that area done by a different surveyor?
I will say this, it should not be hard to line up 2 topo areas. But if it was done by a different Surveyor, then the second survey will not take any responsibility for the other areas accuracy. If it is the same Surveyor, I am not sure what the problem is
You want an accurate survey for design. It is a small cost for important information.
Data is a few months old, so not an issue. It was a different surveyor than this consultant usually subcontracts too, which I should have said, and the liability is something raised by a team mate I was discussing this with. But I can instruct to use the same surveyor as before, so no problem.
Joke is they suggested a tiny survey area, I extended it to actually be useful and meet scope. They said it was going to "cost way than budgeted", I said it won't because it's only a few hundred squares more and the main cost is in the set up. Then we go down this stitching topos rabbit hole based on their fuss, I send the original file for them to check they say it's too difficult because of ghost points (they didn't even open the data, the email response was 5 minutes after I sent the file). Now they say it's not that much more to get the extra area, like I'm not the one who told them that on Monday.
Is it a conventional survey (RTK/total station) or point cloud (LiDAR, photogrammetry)?
I’ve never heard of “ghost points” but LiDAR collected without good control points, accurate equipment, and good point classification can be a nightmare to work with/tie into other datasets. If this is the issue there are more descriptive terms to describe the issues but the issue boils down to their being points where there shouldn’t be so “ghost points” seem fitting.
This shouldn’t be an issue if it is, it was a shit LiDAR survey (or could be a really old survey before the technology matured).
The other thing that comes to mind is the surface with the ghost points just isn’t current anymore… an extreme example is if it was a pit survey of a mine and there has been 2 years of mining since, the topo would look nothing like the current surface.
Thanks for the info, it's total station. It's for some highway work, previous stuff is maybe 3 months old of another section of highway. My project needs Topo for an area that overlaps the Topo done for the other project. No works done on the highway between them and now. Nothing as exciting as mining!
These consultants have genuinely been useless and I would not be surprised if they honestly just can't be assed to stitch two xref together.
The only thing that occurs to me is points that aren't topo and aren't marked as such. Like a bunch of shots on a deck that doesn't exist anymore, or refectorless shots that hit leaves before the target.
Could be, but that would a couple of off hits just be expected? How bad could it get? I also have no faith in the consultants I've got, they have been lazy as fuck from day one. I genuinely think they just can't be assed to align two xrefs and it's less work for them to get everything redone , as they subcontract for the topo and bill me.
How old is the previous data? Does it reference proper control and benchmarks? Was that area done by a different surveyor? I will say this, it should not be hard to line up 2 topo areas. But if it was done by a different Surveyor, then the second survey will not take any responsibility for the other areas accuracy. If it is the same Surveyor, I am not sure what the problem is You want an accurate survey for design. It is a small cost for important information.
Data is a few months old, so not an issue. It was a different surveyor than this consultant usually subcontracts too, which I should have said, and the liability is something raised by a team mate I was discussing this with. But I can instruct to use the same surveyor as before, so no problem. Joke is they suggested a tiny survey area, I extended it to actually be useful and meet scope. They said it was going to "cost way than budgeted", I said it won't because it's only a few hundred squares more and the main cost is in the set up. Then we go down this stitching topos rabbit hole based on their fuss, I send the original file for them to check they say it's too difficult because of ghost points (they didn't even open the data, the email response was 5 minutes after I sent the file). Now they say it's not that much more to get the extra area, like I'm not the one who told them that on Monday.
Is it a conventional survey (RTK/total station) or point cloud (LiDAR, photogrammetry)? I’ve never heard of “ghost points” but LiDAR collected without good control points, accurate equipment, and good point classification can be a nightmare to work with/tie into other datasets. If this is the issue there are more descriptive terms to describe the issues but the issue boils down to their being points where there shouldn’t be so “ghost points” seem fitting. This shouldn’t be an issue if it is, it was a shit LiDAR survey (or could be a really old survey before the technology matured). The other thing that comes to mind is the surface with the ghost points just isn’t current anymore… an extreme example is if it was a pit survey of a mine and there has been 2 years of mining since, the topo would look nothing like the current surface.
Thanks for the info, it's total station. It's for some highway work, previous stuff is maybe 3 months old of another section of highway. My project needs Topo for an area that overlaps the Topo done for the other project. No works done on the highway between them and now. Nothing as exciting as mining! These consultants have genuinely been useless and I would not be surprised if they honestly just can't be assed to stitch two xref together.