Difficulties with datums while importing Esri i3s into ArcGIS Earth

My processing workflow has taken data collected in projected coordinate systems with NAVD88, perform AT and reconstruction with the data still in its original coordinate system and vertical datum. I convert it to WGS84 in an i3s production. Upon bringing the .slpk files into ArcGIS Earth, it becomes evident that the data is floating 250-300m above the ground surface. I believe it is coming from a problem with Context capture's vertical datum shift capabilities, but I'm not sure. Has anyone found a way to fix this yet?

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  • Hi Peter,

    If you observe such vertical shift there is a chance it is also the case in ContextCapture. First can you make sure that you are using the appropriate geoid NAV88 when you import your data ? Also it is possible that ContextCapture support that altimetric grid in "feet" instead of "meters", can you see if it is better when you change your altitude values so to be based as feet instead ?

    Regards
    Pierre
  • All of the coordinate systems were directly specified. However, my version of ContextCapture only currently provides two vertical datums by default: EGM96 geoid height and NGF-IGN69 height (French National Vertical Datum). As such, CC has no vertical datum transformation information for NAVD88 exists within the program.

    On pages 131-132 of the manual it specifies, "Some spatial reference systems use external dependencies which, prior to their use, must be installed in the "data\gdal" subdirectory of ContextCapture installation directory. For instance, a spatial reference system with a custom vertical coordinate system may use a GTX grid to approximate the geoid."

    Does this mean I should just copy additional .gtx files into that subdirectory? Do I also need to import grid transformation files? If so, what format should I use?
  • Hi Peter,

    Sorry this is my fault, I forgot to mention that the NAVD88 vertical datum is available in the latest ContextCapture version only: Build 04.04.05.33.

    Please go to the Bentley software download page and update your version.

    Pierre

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