Reference points in TXT file

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lipo80
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Full Name: Libor Polak
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Reference points in TXT file

Post by lipo80 »

Hi to all,
I am new here. I would like to know what the next step about georeferencing. I have TXT file with points with coordinates in coordinate system (for example S-JTSK), then I have TXT file with coordinates exported from GeoSLAM (refpoints).

In S-JTSK I have 8 points, but in refpoints file there are 10 points. My question is what the next step and how can I use this refpoints TXT file.

My next possibility is CloudCompare, but I need more accuracy.

Thank you very much for all answers.
Libor

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Re: Reference points in TXT file

Post by VXGrid »

Hi Libor

are the points from your target system (the S-JTSK points) at the same location (identical points, different coordinate system) as your local points (GeoSLAM reference points)?

I'm not familar with the Czech S-JTSK system, is it a system without a scale (scale = 1.0) and the coordinates are represented in eucledean (X, Y, Z in meter, not angles/degrees)?

If the answer to both is yes:
When using the latest version of GeoSLAM Draw (3.0 R2 or later), you can open the GeoSLAM Draw project via GeoSLAM Hub and then:
  1. Click one 3D point somewhere in the point cloud.
  2. In the Job Editor of the selected point, import your local points (GeoSLAM reference points).
  3. Delete the first set 3d point by right clicking on it and select delete.
  4. Open the Transformation calculator (top menu bar: "Registration"->Transformation calculator).
  5. Import the identical points into your target system (Reference system in Draw, the one on the left side) (Your local coordinates in the point cloud system should be already inserted automatically).
  6. Click on find constellation on the right hand side.
  7. Now the two points you have extra in your point cloud system should have been removed and all identical points should be in the same row and on the right side you can see the Residuals for every single identical point between reference and point cloud system, at the bottom left you see the global transformation values and the expected accuracies.
  8. Last but not least click on create align and your project will be transformed into the reference system, please keep in mind that all created elementes in the Job List will be removed.
If this is not working as expected, please get in touch with GeoSLAM Support.

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lipo80
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Joined: Wed May 22, 2019 1:18 pm
Full Name: Libor Polak
Company Details: TOPGIS Brno
Company Position Title: laserscanning specialist
Country: Czech
Linkedin Profile: Yes
Location: Czech Republic

Re: Reference points in TXT file

Post by lipo80 »

Hi Martin,
thank you very much. I've tried it and it works :like:

I had a one more question about georeferenced cloud, but I've find out how it works... exporting georeferenced pointcloud to LAS in tool Modules.

Thank you very much, Martin, you helped me so much :-)

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