Scan planning for open fields

[scottkim]

I have experience with scanning, but I have never done a scan of an open field like the one below. There are no artifacts nearby.
I am at a loss as to how to create a scan chain. So I am asking for your help.
How can I do a scan plan to get a more accurate scan?

I will use the items below.

- FARO S350 scanner
- FARO Scene & Cyclone register 360
- Uses up to 24ea x 200mm spheres
- 20+ targets are set up and a surveyor surveys them.

Thank you.

[jaredmatthews]

Assuming you are just picking up ground contours for this?:

I think it would be much less painful, and more economical to either:

A) Survey this traditionally using a Total Station and detail pole
B) Survey this using a drone

[scottkim]

Since this is part of a power plant, using drones is not easy as there is a complicated approval process. Also, we don't have that experience.
We also want to cover this area with the laser scan because there is a power plant building to the north of this scan area and a small building to the south that needs to be included in the scan as well.

Thanks for your comment.

[jaredmatthews]

Thanks for the extra detail.

I would highly recommend hiring the services of a qualified surveyor with the right equipment to help out.

With the right equipment and survey workflow, he can set out some survey stations around both of the buildings you are looking to scan.

You can then capture these stations with your scanner and reference them to the same grid as the Total station. (The surveyor can also pick up all of the ground area with a detail pole)

Theres good reason why large open areas like what you are describing are not scanned with a Terrestrial scanner.

[scottkim]

Your comment gave me an opportunity to reconsider this.
thank you

[gordonired]

I would echo what Jared has said. I love scanning and would pick it over surveying with a total station every time if possible. That being said, with the brief description given it does look a total station would be a better tool, both with the lack of features (you use cloud to cloud I assume?) and large distances covered.

Myself, and I'm sure others on this forum, have learned the hard way that C2C can introduce some nasty creeping errors here and there. I started taking advice from here, and integrated total station/surveying techniques to augment my laser scanning skills. A nice easy project like this would be a good oppourtunity for you to rent some gear (usually a couple hundred per day), and get a bit of rudimentary training and start to integrate it into your own workflows.

If you're very set on only a scanner, one thought that comes to my mind is to build some temporary targets. Something out of wood/plywood maybe? I'd image a pyramid or square shape, not 2D. Put some checkerboards on it, have the surveyors shoot those points in as well. You'd likely need to scan on high resolution settings to help your software recognize those targets if they are far away, which bumps your scanning time up.

[gsisman]

Assuming you are just picking up ground contours for this?:

I think it would be much less painful, and more economical to either:

A) Survey this traditionally using a Total Station and detail pole
B) Survey this using a drone

Or from the surrounding description -RTK topo. The scanner also would get only the surface vegetation in some cases not the true ground surface ,depending on bare earth verses long grass versus manicured grass

[MarkJLane]

I made Plan Scan to make it easier to make scanning mudmaps like this. Check it out here - https://tls.tools/PlanScan/

Seems like you'll certainly need plenty of targets though!

[smacl]

Assuming you are just picking up ground contours for this?:

I think it would be much less painful, and more economical to either:

A) Survey this traditionally using a Total Station and detail pole
B) Survey this using a drone

Or from the surrounding description -RTK topo. The scanner also would get only the surface vegetation in some cases not the true ground surface ,depending on bare earth verses long grass versus manicured grass

Agreed that this is the ideal use case for a RTK unit over total station and has the added advantage of being in national grid without having to bring in external control. Good point about vegetation too, using a pole and picking points removes a lot of ambiguity here. For a very big area drone mounted LIDAR or backpack mobile mapping can be a great solution, but for smaller areas, RTK can be much more efficient and accurate.

[Emanuele]

Hi,
A solution that I use in similar cases is the use of the scanner in polygonal mode with forced centering similar to a total station.
The 200 mm spheres guarantee good precision even up to 50-60 m.
If possible I also acquire the rtk position of the mirror center using a special support for the GNSS antenna