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Author Topic: Error: Vertical datum missing  (Read 5598 times)

Isaac H. E.

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Error: Vertical datum missing
« on: February 23, 2021, 12:14:07 PM »
Hello Everyone,

I'm stuck with a project that I did on a computer that had a vertical datum defined, this datum was based on a non public geoid file that was stored on a given path that I don't remember.

Now I'm on a different computer and I don't have that same vertical datum installed on the same path as in the original computer and when I open the MetaShape project I get lot's of:
Error: Vertical datum missing


And among other issues I'm unable to see coordinates (lower right corner), I'm unable to see camera positions on the Ortho pane, ...
I do have the geoid file but I would like to specify a different path, would that be possible? If so, how?

I'm working in MetaShape professional 1.7.0

Thanks

Isaac

Paulo

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Re: Error: Vertical datum missing
« Reply #1 on: February 23, 2021, 02:13:28 PM »
Hi Isaac,

normally the geoid should be stored in the geoids folder under the Metashape installation directory (for all users). If you want only a particular  user to be able to access the geoid then it should be in :

C:\Users\user_name\AppData\Local\Agisoft\Metashape Pro\geoids
« Last Edit: February 23, 2021, 02:26:24 PM by Paulo »
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Paul Pelletier,
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Isaac H. E.

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Re: Error: Vertical datum missing
« Reply #2 on: February 24, 2021, 12:54:07 AM »
Hi Paulo,


First of all I would like to take the time to thank you for your effort in responding to my post.


While I do agree with you on that geoids should be generally stored in the geoids folder within Metashape's folder I did not did so because I created those geoid undulation files and they are not fully compliant with Agisoft standard (I suspect the EXIF tag that describes the EPSG code / description is missing) which meant that every time I started Metashape I got an error, which was annoying.


In any case my original question stands, is there a way to to solve my current situation? I do need to specify a new geoid path within the existing Metashape project, would that be possible?


Many thanks in advance!


Isaac


Paulo

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Re: Error: Vertical datum missing
« Reply #3 on: February 24, 2021, 01:35:38 AM »
Hey Isaac,

if your geoid file is not  in the geoids folder or is not properly formated, then I would suggest to follow steps in following tutorial https://agisoft.freshdesk.com/support/solutions/articles/31000148332-how-to-use-height-above-geoid-for-the-coordinate-system, following the second case:
Quote
the geoid file should be created from the external file with the undulation grid data,
Then you should have a geoid file in correct folder with  proper Agisoft format with VERT_DATUM entry in Tiff description.

In attached screen, you see details of es_ign_egm08-rednap geoid in local Geoids folder. The file`s metadata are:
Code: [Select]
Driver: GTiff/GeoTIFF
Files: C:\Users\paul.pelletier\AppData\Local\Agisoft\Metashape Pro\geoids\es_ign_egm08-rednap.tif
Size is 841, 541
Coordinate System is:
GEOGCS["ETRS89",
    DATUM["European_Terrestrial_Reference_System_1989",
        SPHEROID["GRS 1980",6378137,298.2572221010002,
            AUTHORITY["EPSG","7019"]],
        TOWGS84[0,0,0,0,0,0,0],
        AUTHORITY["EPSG","6258"]],
    PRIMEM["Greenwich",0],
    UNIT["degree",0.0174532925199433],
    AUTHORITY["EPSG","4258"]]
Origin = (-9.508333329999999,44.008329730000000)
Pixel Size = (0.016666660000000,-0.016666660000000)
Metadata:
  AREA_OR_POINT=Area
  TIFFTAG_IMAGEDESCRIPTION=VERT_DATUM["EGM2008 REDNAP IGN",2005]
Image Structure Metadata:
  COMPRESSION=LZW
  INTERLEAVE=BAND
Corner Coordinates:
Upper Left  (  -9.5083333,  44.0083297) (  9d30'30.00"W, 44d 0'29.99"N)
Lower Left  (  -9.5083333,  34.9916667) (  9d30'30.00"W, 34d59'30.00"N)
Upper Right (   4.5083277,  44.0083297) (  4d30'29.98"E, 44d 0'29.99"N)
Lower Right (   4.5083277,  34.9916667) (  4d30'29.98"E, 34d59'30.00"N)
Center      (  -2.5000028,  39.4999982) (  2d30' 0.01"W, 39d29'59.99"N)
Band 1 Block=256x256 Type=Float32, ColorInterp=Gray
  NoData Value=-32767
« Last Edit: February 24, 2021, 07:30:55 AM by Paulo »
Best Regards,
Paul Pelletier,
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Isaac H. E.

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Re: Error: Vertical datum missing
« Reply #4 on: February 24, 2021, 01:20:54 PM »
Hey Paulo,


Thanks yet again!  :)


Yes, I'm aware of the structure of the EXIF tags within the TIFF file the issue is that I need to know (exactly) what to write in to the tags and I'm not really sure where to get that information furthermore I'm not particularly comfortable using  EXIFTOOL from Phil Harvey so by now I have been using "my" geoids without issues, only when I changed from computer problems arised due to the different paths.


In fact my geoids are very small, they only cover Catalunya so maybe if I post them here in the forums someone can help me and add the tags.  :-\




Paulo

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Re: Error: Vertical datum missing
« Reply #5 on: February 24, 2021, 02:02:38 PM »
Isaac,

what you have to do is follow the steps outlined in tutorial I mentioned in previous post, and MS will automatically copy your input tif file to Geoids folder and write the correct TiffTag corresponding to VERT_DATUM["EGM2008 Catalunya ",2005]

So you do not have to write it yourself...

Attached is the new geoid file for EGM2008 ETRS89 Catalunya D5951. I am sure you can follow tutotial to do same operation for EGM2008 WGS84 Catalunya

The following screen copy shows how you can:
1. select an existing CRS ETRS89 / UTM zone 30N and with edit button open Edit Coordinate System window;
2. in Edit Coordinate System window, change its name and in Vertical CS drop down menu select Custom;
3. in Edit Vertical Coordinate System window, enter its name and in Datum drop down menu select EGM2008 Catalunya. Accept with OK and new Compound CS wil be created.

Second screen copy shows point 2 with its geoid height shown in MS and Global mapper.

Hope this can be of some help,
« Last Edit: February 27, 2021, 01:31:57 AM by Paulo »
Best Regards,
Paul Pelletier,
Surveyor