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Author Topic: Unsupported datum transformation  (Read 2025 times)

Jakub Koutný

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Unsupported datum transformation
« on: November 07, 2021, 11:37:07 PM »
Hello,

I am trying to export a dense cloud with an outer boundary. However I am getting an "unsupported datum transformation" error.

Point cloud is in S-JTSK / Krovak East North (EPSG::5514) after exporting it from DJI Terra.
Boundary shape is made in Qgis with the same coordinate system. (as shown in the picture)

Does anybody know where might be the problem or if there is some other way to do it?

Thank you in advance.  :)

RHenriques

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Re: Unsupported datum transformation
« Reply #1 on: November 08, 2021, 06:58:52 AM »
Are you using any geoid model for altimetry transformation?

Paulo

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Re: Unsupported datum transformation
« Reply #2 on: November 08, 2021, 09:32:42 AM »
Halo Jakub,

it seems that the polygon export from qGis using S-JTSK / Krovak East North produces Coordinates out of range.....

I would add your point cloud into Metashape (first setting the chunk CS  using EPSG code 5514), create the outer boundary  and then export specifying the CS and checking the correct toWGS84 parameters as there up to 5 different sets of parameters... see following

PS. I think I found why qGis and possibly DJI Terra export coordinates out of range. It seems it uses  AUTHORITY["EPSG","102067"] which is different from 5514 (XY rotated and X inversed)
:
Code: [Select]
PROJCS["S-JTSK_Krovak_East_North",
GEOGCS["GCS_S_JTSK",
DATUM["D_S_JTSK",
SPHEROID["Bessel_1841",6377397.155,299.1528128]],
PRIMEM["Greenwich",0],
UNIT["Degree",0.017453292519943295]],
PROJECTION["Krovak"],
PARAMETER["False_Easting",0],
PARAMETER["False_Northing",0],
PARAMETER["Pseudo_Standard_Parallel_1",78.5],
PARAMETER["Scale_Factor",0.9999],
PARAMETER["Azimuth",30.28813975277778],
PARAMETER["Longitude_Of_Center",24.83333333333333],
PARAMETER["Latitude_Of_Center",49.5],
PARAMETER["X_Scale",-1],
PARAMETER["Y_Scale",1],
PARAMETER["XY_Plane_Rotation",90],
UNIT["Meter",1],
AUTHORITY["EPSG","102067"]]
« Last Edit: November 08, 2021, 10:44:09 AM by Paulo »
Best Regards,
Paul Pelletier,
Surveyor