Which is the most accurate way to merge drone and pointcloud projects?

Discuss all Leica Geosystems related issues here.
Post Reply
miguel.antunes
I have made 30-40 posts
I have made 30-40 posts
Posts: 32
Joined: Wed Aug 22, 2018 9:50 am
Full Name: Miguel Angelo Morais Antunes
Company Details: Engineering
Company Position Title: Surveyor
Country: Portugal
Linkedin Profile: No
Been thanked: 1 time

Which is the most accurate way to merge drone and pointcloud projects?

Post by miguel.antunes »

Hello everyone,

Its pretty like I said in the subject, I want to merge this two but can't find a proper way to do it, I try in recap but unsuccessfully
User avatar
landmeterbeuckx
V.I.P Member
V.I.P Member
Posts: 859
Joined: Tue May 01, 2012 5:19 pm
Full Name: Lieven Beuckx
Company Details: Studiebureau Beuckx
Company Position Title: Owner
Country: Belgium
Linkedin Profile: Yes
Has thanked: 68 times
Been thanked: 174 times

Re: Which is the most accurate way to merge drone and pointcloud projects?

Post by landmeterbeuckx »

pointcab is the tool for this
LSBbvba
Surveying services - 3D Laserscanning
Tel : +32477753126
www.lsbbvba.be
[email protected]
Ioannis
V.I.P Member
V.I.P Member
Posts: 355
Joined: Sun Jul 24, 2016 6:19 am
Full Name: Ioannis Papas
Company Details: techical office
Company Position Title: CEO
Country: EU
Skype Name: -
Linkedin Profile: Yes
Has thanked: 31 times
Been thanked: 21 times

Re: Which is the most accurate way to merge drone and pointcloud projects?

Post by Ioannis »

For sure Cyclone for professional results!
miguel.antunes
I have made 30-40 posts
I have made 30-40 posts
Posts: 32
Joined: Wed Aug 22, 2018 9:50 am
Full Name: Miguel Angelo Morais Antunes
Company Details: Engineering
Company Position Title: Surveyor
Country: Portugal
Linkedin Profile: No
Been thanked: 1 time

Re: Which is the most accurate way to merge drone and pointcloud projects?

Post by miguel.antunes »

Thank you guys, appreciated
VXGrid
V.I.P Member
V.I.P Member
Posts: 229
Joined: Fri Feb 24, 2017 10:47 am
Full Name: Martin Graner
Company Details: PointCab GmbH
Company Position Title: Research and Development
Country: Germany
Linkedin Profile: No
Has thanked: 51 times
Been thanked: 56 times
Contact:

Re: Which is the most accurate way to merge drone and pointcloud projects?

Post by VXGrid »

miguel.antunes wrote: Fri Apr 30, 2021 3:22 pm Hello everyone,

Its pretty like I said in the subject, I want to merge this two but can't find a proper way to do it, I try in recap but unsuccessfully
So the most accurate way would be to merge every single patchlet of the drone point cloud by doing least squares minimaziation onto the static? point cloud.
However nobody does that (I think there are no tools for that at all).

So all you need to do is to bring both point clouds into the same coordinate system using a 6 parameter transformation (if the drone data is scaled correctly). This means you pick in both data sets minimum 3 identical points, and then transform one project into the other.
And then if feasable, you can apply an ICP to get the data even more aligned (depending on point accuracy of the drone data).

I think in CloudCompare you would be able to do this. Wouldn't wounder me if there is a thread on here describing how to do it in there.

In what data format do you have your drone data and your static scan data?
User avatar
Dave Andrews
V.I.P Member
V.I.P Member
Posts: 131
Joined: Thu Oct 18, 2012 8:58 pm
Full Name: Dave Andrews
Company Details: R.E. Warner Associates Inc.
Company Position Title: 3d Scanning Coordinator
Country: USA
Linkedin Profile: Yes
Location: Canton, Ohio
Has thanked: 2 times
Been thanked: 7 times
Contact:

Re: Which is the most accurate way to merge drone and pointcloud projects?

Post by Dave Andrews »

I guess this would be for future projects and won't really help now, survey work.
"The harder you work, the harder it is to surrender."
Woody Hayes
jamesworrell
V.I.P Member
V.I.P Member
Posts: 426
Joined: Mon Jun 16, 2014 1:45 pm
Full Name: James Worrell
Company Details: Bennett and Francis
Company Position Title: Director
Country: Australia
Linkedin Profile: Yes
Location: Brisbane, Queensland, Australia
Been thanked: 47 times
Contact:

Re: Which is the most accurate way to merge drone and pointcloud projects?

Post by jamesworrell »

Create overall point cloud from laser scan + imagery in a photogrammetry SfM software that supports hybrid inputs - in something like Reality Capture or Context Capture or Skyline Photomesh ..

Failing that - use ground control points (could include vertices from obvious structure) from laser/survey in photogrammetry project - so same coordinate system.

Failing that - photogrammetry is probably a bit too much of a fudge without control, but again, you could use corners of gutters or painted lines on roads or other features in a point cloud registration software to rotate/translate etc the point cloud from drone to "fit" the survey stuff.

Or a bit of both. We have used Context Capture in the past to generate point cloud from imagery (with ground control), which we then trimmed off a bit and used in Cyclone/Recap et al to model roof data which we hadn't laser scanned.
User avatar
smacl
Global Moderator
Global Moderator
Posts: 618
Joined: Tue Jan 25, 2011 5:12 pm
Full Name: Shane MacLaughlin
Company Details: Atlas Computers Ltd
Company Position Title: Managing Director
Country: Ireland
Linkedin Profile: Yes
Location: Ireland
Has thanked: 202 times
Been thanked: 198 times
Contact:

Re: Which is the most accurate way to merge drone and pointcloud projects?

Post by smacl »

VXGrid wrote: Fri Apr 30, 2021 5:55 pmSo all you need to do is to bring both point clouds into the same coordinate system using a 6 parameter transformation (if the drone data is scaled correctly). This means you pick in both data sets minimum 3 identical points, and then transform one project into the other.
And then if feasable, you can apply an ICP to get the data even more aligned (depending on point accuracy of the drone data).
This highlights the important issue of what projections and reduction were used to derive the coordinates in the drone point cloud. For drones using RTK GPS, this may be a grid which includes scale factor. Stuff I've been involved in recently in the UK for example has been provided UTM Zone 30N. If you have sufficient common ground control points between the scan data and the aerial data, it is worth running a 6 parameter (rigid) and 7 parameter (uniform scale) transformation, look at the residuals, and decide which is more appropriate. In SCC we allow an extensive range of geodetic transformations to be applied to point clouds which are collected using RTK and delivered in a well known grid (e.g. UTM 30N, OSTN15, HS215, etc...) This allows for combination of data where sufficient common control may not be available and independently checking the results with terrestrial RTK. The video below illustrates this.


youtu.be/1D92rHHyyxQ

A lot of this depends very much on the total size of the site and whether a project grid has been established. On smaller sites or individual structures, running a scale free grid based on local control makes most sense. On a larger project, you have to adopt the project grid, bring all data into that grid, and check goodness of fit of each survey using established control or hard features in that grid. Worth noting that 6 and 7 parameter transforms will perturb levels differently to geodetic transforms that employ distinct horizontal and vertical elements.
Post Reply

Return to “Leica Geosystems”