Can't load local geoid model into metashape

[foxx1]

Hello,

I am trying to add a new vertical coordinate system following the tutorial here: https://agisoft.freshdesk.com/support/solutions/articles/31000148332-how-to-use-height-above-geoid-for-the-coordinate-system.
When it comes to step, the message "Cannot load Geoid" appears. The geoid model is an officially used geoid used by the local government here. So why is it not working?

Another try with the integrated vertical cordinate system DHHN2016 (EPSG::7837) fails as well. After choosing the vertical CS the following message appears: "The selected vertical is not available. Please configure the transformation" What does this message mean? When the vertical coordinate system is already implemented to the dropdown list of metashape, I assume that the transformation should work!?

Thanks in advance
foxx

[Alexey Pasumansky]

Hello foxx,

Can you please specify, which compound coordinate system you are using (or based on which planar system you are trying to create compound system with the vertical datum)?

Additionally please specify, which format of the undulation grid file you are using? Can you share it here, provide a download link to the external resource or send the file to support@agisoft.com?

[foxx1]

Hello Alexey,

i've answered to your questions via mail to support@agisoft.com

Thank you!
foxx

[foxx1]

Hello,

I did not receive any response via mail. So I will upload the documentation and undulation model here. May be someone can help

https://wetransfer.com/downloads/b4b75e9704754d986b8786fc953c0f5c20201007105505/bdc25e72c3ab61a7efb6e1d64b8e4c4220201007105522/fa8123

Greetings

[Paulo]

Hi  foxx1,

i did create a compound CS using the undulation file you submitted....see attached prj file.

Just download the geoid file in attached link https://drive.google.com/file/d/1NtgVX6VsClxiqjyR4WeXDb47D0u6TeSJ/view?usp=sharing and put it in your metashape geoids folder and it should work...

[foxx1]

Thanks Paulo, works perfect.

What did you exactly do to create the compound coordinate system? Or in other words: What was wrong with the files I sent? I'm interested in doing such things by myself.

Greetings and thanks again!

[Paulo]

Hi foxx1,

I just followed the steps described in the second part of the geoids tutorial referring to

What to do, if the desired geoid is not present in the list on Agisoft's web-site, but you have an undulation grid file, that defines the offsets between the ellipsoid and geoid:

and voila! And your undulation file has no problem...when you add it, MS will make a copy of it into the Metashape geoids folder with a TIFF_DESC entry corresponding to the Vertical Datum name you entered (in my case Geobasis NRW). See extracted Metadata from your tif file copied in geoids folder:

Code: [Select]

FILENAME=C:\Users\paul.pelletier\AppData\Local\Agisoft\Metashape Pro\geoids\Undulationsmodell_GeobasisNRW_v01.tif
DESCRIPTION=Undulationsmodell_GeobasisNRW_v01.tif
UPPER LEFT X=5.8313800024
UPPER LEFT Y=52.5708599995
LOWER RIGHT X=9.5063800024
LOWER RIGHT Y=50.2790599995
WEST LONGITUDE=5.83138000
NORTH LATITUDE=52.57086000
EAST LONGITUDE=9.50638000
SOUTH LATITUDE=50.27906000
UL CORNER LONGITUDE=5.83138000
UL CORNER LATITUDE=52.57086000
UR CORNER LONGITUDE=9.50638000
UR CORNER LATITUDE=52.57086000
LR CORNER LONGITUDE=9.50638000
LR CORNER LATITUDE=50.27906000
LL CORNER LONGITUDE=5.83138000
LL CORNER LATITUDE=50.27906000
PROJ_DESC=Geographic (Latitude/Longitude) / ETRS89 / arc degrees
PROJ_DATUM=ETRS89
PROJ_UNITS=arc degrees
EPSG_CODE=EPSG:4258
COVERED AREA=6492785 ha
LOAD TIME=10.56 s
FILE_CREATION_TIME=07/10/2020 06:40:38 a. m.
FILE_MODIFIED_TIME=07/10/2020 06:40:51 a. m.
GDAL_NO_DATA_VALUE=-3.40282e+38
NUM COLUMNS=13126
NUM ROWS=8186
NUM BANDS=1
PIXEL WIDTH=0.00028 arc degrees
PIXEL HEIGHT=0.00028 arc degrees
MIN ELEVATION=42.448 m
MAX ELEVATION=48.483 m
ELEVATION UNITS=METERS
BIT DEPTH=32
SAMPLE TYPE=32-bit Floating Point
TIFF_DESC=VERT_DATUM["Geobasis NRW",2005]
GEOG_CITATION=ETRS89
PHOTOMETRIC=Greyscale (Min is Black)
BIT_DEPTH=32
SAMPLE_FORMAT=Floating Point
TILE_WIDTH=256
TILE_HEIGHT=256
COMPRESSION=LZW
PIXEL_SCALE=( 0.00028, 0.00028, 1.0 )
TIEPOINTS=( 0.00, 0.00, 0.00 ) --> ( 5.8312400024, 52.5709999995, 0.0000000000 )
MODEL_TYPE=Geographic lat-long system
RASTER_TYPE=Pixel is Area
GeoTIFF::GeographicTypeGeoKey=4258
GeoTIFF::GeogGeodeticDatumGeoKey=6258
GeoTIFF::GeogEllipsoidGeoKey=7019
GeoTIFF::GeogToWGS84GeoKey={ 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000 }
GeoTIFF::GeogAngularUnitsGeoKey=9102
and when you save your Compound CS, the same VERT_DATUM will be present in the Vertical CS section of your prj file as in:

Code: [Select]

COMPD_CS["ETRS89 / UTM zone 32N + Geobasis NRW",
PROJCS["ETRS89 / UTM zone 32N",
GEOGCS["ETRS89",
DATUM["European Terrestrial Reference System 1989",
SPHEROID["GRS 1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],TOWGS84[0,0,0,0,0,0,0],AUTHORITY["EPSG","6258"]],
PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],
UNIT["degree",0.01745329251994328,AUTHORITY["EPSG","9102"]],
AUTHORITY["EPSG","4258"]],
PROJECTION["Transverse_Mercator",AUTHORITY["EPSG","9807"]],
PARAMETER["latitude_of_origin",0],
PARAMETER["central_meridian",9],
PARAMETER["scale_factor",0.9996],
PARAMETER["false_easting",500000],
PARAMETER["false_northing",0],
UNIT["metre",1,AUTHORITY["EPSG","9001"]],
AUTHORITY["EPSG","25832"]],
VERT_CS["Geobasis NRW",
VERT_DATUM["Geobasis NRW",2005],
UNIT["metre",1,AUTHORITY["EPSG","9001"]]]]

[foxx1]

Thanks Paulo 

[foxx1]

Hey Paulo,

I am sorry, I have to ask you another question:
I was comparing the Geotiff I sent you vs the GeoTiff you sent me back and I noticed that the height offset for the same xy coordinates ist not the same, see picture, see atached file. How is it possible?

I am still wondering why the second step "What to do, if the desired geoid is not present in the list on Agisoft's web-site, but you have an undulation grid file, that defines the offsets between the ellipsoid and geoid:" works for you but not for me. When I try to add the undulation file I get the "Can't load geoid" message.

Thanks in advance again
foxx1

[Paulo]

Hello foxx1,

on my side, i do not see any difference in undulation values between original file and copied file to geoids folder...

It seems that when you try to create your own new geoids file, try using different vertical datum name for example, I recreated one but specified NRW geoid as Vertical datum and got a new geoid (whose name has 2 appended) with no error...but if I tried to specify datum starting with Geobasis... then I got Cant load geoid error

[wojtas]

Hello,

I experience the same problem with importing local geoid.
I follow every step as described in https://agisoft.freshdesk.com/support/solutions/articles/31000148332-how-to-use-height-above-geoid-for-the-coordinate-system
- but with no success.

Problem describtion:

I am trying to import Lat/Long/Alt table with undulation values that is stored in TXT file (PL-KRON86-NH) and add this file as Vertical CS into ETRS89 / Poland CS2000 Zone 7 which is stored in Metashape coordinates system. My workflow is as follow:
1. Paste TXT file (Lat/Long/Alt) into C:\Program Files\Agisoft\Metashape Pro\geoids
2. Run Metashape -> Reference -> Reference Settings -> Coordinate System -> More... -> Select Coordinate System ->  ETRS89 / Poland CS2000 Zone 7 -> Edit -> Edit CS Name -> Select Vertical CS -> Custom -> Add Name in Edit Coordinate System dialog -> Datum -> Add.. -> Select TXT file (PL-KRON86-NH)
3. In impot geoid parameters I select WGS-84 as geographic CS becouse of the values in TXT file. I also name Vertical datum as before ("PL-KRON86-NH") and select no data value as default.
4. Can't load geoid error.

So far I tried to solve this problem by:
- in step no. 3 select geographic CS as ETRS89 which correspondes to horizontal CS -> no success
- in QGIS reproject Lat/Long/Alt table to ETRS89 CS with X,Y values -> no success

I attach screenshots from Agisoft Metashape with all the parameters I enter during this process.
Geoid "PL-KRON86-NH" download link: https://we.tl/t-LvEe2cxItq

Greetings

[Paulo]

Hi wojtas,

yes it seems that when MS creates the geoid tif file it does not create the correct description corresponding  to ESPG entry for VERT_DATUM. The description is set as  ["PL-KRON86-NH"]
where PL-KRON86-NH was the vertical datum entered. But the entry should be VERT_DATUM["PL-KRON86-NH",2005]. See attached screen copy.

Maybe support or Alexey can help resolve this issue...

[Paulo]

hI Wojtas,

I was able to fix the geoid file so that it corresponds to the following compound CS:

Code: [Select]

COMPD_CS["ETRS89 / Poland CS2000 zone 7 + PL KRON86 NH height",
PROJCS["ETRS89 / Poland CS2000 zone 7",
GEOGCS["ETRS89",
DATUM["European Terrestrial Reference System 1989",
SPHEROID["GRS 1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],TOWGS84[0,0,0,0,0,0,0],AUTHORITY["EPSG","6258"]],
PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],
UNIT["degree",0.01745329251994328,AUTHORITY["EPSG","9102"]],
AUTHORITY["EPSG","4258"]],
PROJECTION["Transverse_Mercator",AUTHORITY["EPSG","9807"]],
PARAMETER["latitude_of_origin",0],
PARAMETER["central_meridian",21],
PARAMETER["scale_factor",0.999923],
PARAMETER["false_easting",7500000],
PARAMETER["false_northing",0],
UNIT["metre",1,AUTHORITY["EPSG","9001"]],
AUTHORITY["EPSG","2178"]],
VERT_CS["PL KRON86 NH height",
VERT_DATUM["PL KRON86 NH",2005],
UNIT["metre",1,AUTHORITY["EPSG","9001"]]]]
To do this I edited the ImageDescription tag with Tiff Editor to VERT_DATUM["PL KRON86 NH",2005]
see attached screen copy
The edited geoid file can be downloaded from https://drive.google.com/file/d/1IHnV6maKmQF0-RNHxM0N2ntATeWpGVU2/view?usp=sharing
Still it is very convoluted way to fix a problem!

[wojtas]

Hi Paulo!

Thank you very much for your help, everything works fine you are very smart!

Cheers   

[CoDiZan]

Hi
I have the same problem with EPSG 2176 and My Local Geoid
maybe someone help me
I attach the text file of my goidy Table Lat / Lon / Alt (* .txt)
https://drive.google.com/file/d/1HnspRihjFNnRouDzBn7bYhP_G2O2L0Hx/view?usp=sharing