Selected vertical datum is unavailable, Please configure datum transformation

[Ardu]

Good day,

See attached screenshot for error message when selecting HS2 Survey Grid + HS2-VRF height.

Any other UK Coordinate system is working fine.

I can obviously work in local coordinates, but my client requires outputs/deliverables in WGS84 versions too, then I can't do that because local coordinates is not tied to Global positions & levels

Can you please propose a resolve, I have all the UK based Geoids imported & loaded, but no joy.

Thanks in advance

[Paulo]

Hello Ardu,

do you have the VRF height geoid file? also does the the HS2 datum involve some sort of NTv2 transformation grid to ETRS89? Is it available? We would need these to configure the transformation....

[Ardu]

Paulo,

How can I share the files with you, it's too big for upload to this post

[Paulo]

Hello,

 you can share thru any web sharing service as Google Drive,....

[olihar]

Did you place the Geoid file in the Geoid folder?

[Paulo]

Hello Ardu,

do you have the VRF height geoid file? also does the HS2 datum involve some sort of NTv2 transformation grid to ETRS89? Is it available? We would need these to configure the transformation....

Regarding the NTv2  grid offset, I did find a file HS2TN15_NTv2.gsb.

Code: [Select]

Driver: NTv2/NTv2 Datum Grid Shift
Files: C:\Users\Asus\Downloads\HS2TN15_NTv2.gsb
Size is 769, 529
Coordinate System is:
GEOGCRS["WGS 84",
    DATUM["World Geodetic System 1984",
        ELLIPSOID["WGS 84",6378137,298.257223563,
            LENGTHUNIT["metre",1]]],
    PRIMEM["Greenwich",0,
        ANGLEUNIT["degree",0.0174532925199433]],
    CS[ellipsoidal,2],
        AXIS["geodetic latitude (Lat)",north,
            ORDER[1],
            ANGLEUNIT["degree",0.0174532925199433]],
        AXIS["geodetic longitude (Lon)",east,
            ORDER[2],
            ANGLEUNIT["degree",0.0174532925199433]],
    ID["EPSG",4326]]
Data axis to CRS axis mapping: 2,1
Origin = (-3.002083333333333,53.502083333333331)
Pixel Size = (0.004166666666667,-0.004166666666667)
Metadata:
  GS_TYPE=SECONDS
  VERSION=NTv2.0
  SYSTEM_F=HS2SD
  SYSTEM_T=ETRS89
  MAJOR_F=6378137
  MINOR_F=6356752.314
  MAJOR_T=6378137
  MINOR_T=6356752.314
  SUB_NAME=L2C
  PARENT=NONE
  CREATED=18122018
  UPDATED=18122018
Subdatasets:
  SUBDATASET_0_NAME=NTv2:0:C:\Users\Asus\Downloads\HS2TN15_NTv2.gsb
  SUBDATASET_0_DESC=L2C
Corner Coordinates:
Upper Left  (  -3.0020833,  53.5020833) (  3d 0' 7.50"W, 53d30' 7.50"N)
Lower Left  (  -3.0020833,  51.2979167) (  3d 0' 7.50"W, 51d17'52.50"N)
Upper Right (   0.2020833,  53.5020833) (  0d12' 7.50"E, 53d30' 7.50"N)
Lower Right (   0.2020833,  51.2979167) (  0d12' 7.50"E, 51d17'52.50"N)
Center      (  -1.4000000,  52.4000000) (  1d24' 0.00"W, 52d24' 0.00"N)
Band 1 Block=769x1 Type=Float32, ColorInterp=Undefined
  Description = Latitude Offset (arc seconds)
Band 2 Block=769x1 Type=Float32, ColorInterp=Undefined
  Description = Longitude Offset (arc seconds)
  Metadata:
    positive_value=west
Band 3 Block=769x1 Type=Float32, ColorInterp=Undefined
  Description = Latitude Error
Band 4 Block=769x1 Type=Float32, ColorInterp=Undefined
  Description = Longitude Error
 However, the offsets (in seconds) vary as:

Code: [Select]

<PAMDataset>
<PAMRasterBand band="1">
<Description>latitude_offset</Description>
<Metadata>
<MDI key="STATISTICS_MINIMUM">-68.846298217773</MDI>
<MDI key="STATISTICS_MAXIMUM">77.617301940918</MDI>
<MDI key="STATISTICS_MEAN">4.0210448942308</MDI>
<MDI key="STATISTICS_STDDEV">41.648098551587</MDI>
<MDI key="STATISTICS_VALID_PERCENT">100</MDI>
</Metadata>
</PAMRasterBand>
<PAMRasterBand band="2">
<Description>longitude_offset</Description>
<Metadata>
<MDI key="STATISTICS_MINIMUM">-149.59609985352</MDI>
<MDI key="STATISTICS_MAXIMUM">120.87783050537</MDI>
<MDI key="STATISTICS_MEAN">-13.549494760087</MDI>
<MDI key="STATISTICS_STDDEV">76.668279012399</MDI>
<MDI key="STATISTICS_VALID_PERCENT">100</MDI>
</Metadata>
</PAMRasterBand>These values (if in arcseconds) are huge (-68.846298217773 to 77.617301940918 in lat and -149.59609985352 to 120.87783050537 in lon).

Do you know if they are correct? Or do we have to scale them?