2022 07 29 Meeting Minutes - OpenNavigationSurface/crs_specification GitHub Wiki

2022-07-29 0800 ET on Google Meet

  1. Introductions (Andre, Weston and Glen)
  2. Discussion of how to collaborate - Use Github
  3. Next meetings - next week on 2022-08-05 at 0800 on Google Meet. Follow on meetings will be in September.
  4. Begin Discussion of problem - Stated issue is how to store CRS(s) in BAG, but the real issue is how to store the information to support transformations to other CRS to support downstream work (such as NOAA/OCS/NBS project).
  5. Supporting transformations is a larger issue that is not generally solved, especially for vertical datums. This is a current challenge for the industry as higher accuracy becomes a requirement.
  6. Could EGM2008 could be helpful?
  7. Do we want to keep the main CRS definition in the XML? Could put the vertical CRS definition in the HDF5. Since all other information to support raster georeferencing, such as the resolution and corner position, are in the XML we may as well keep it there.
  8. Backward compatibility as a requirement. Does moving to WKT2 break backward compatibility for the BAG library and GDAL?
  9. Chris joins and does introduction.
  10. WKT1 is problematic as it is poorly specified. WKT2 is better and could be a possible solution.
  11. Maybe with the update in the BAG we should consider forcing WKT2 as a standard and break backward compatibility for those that can't use it.
  12. We should confirm how the BAG lib operates. Does it return whatever is in the field and doesn’t enforce, parse, or care what is in the field? Check GDAL as well?
  13. Can a BoundCRS be more than a single step (abridged)?
  14. DerivedCRS would not work in NOAA’s vertical datum description because it is not a conversion, it is transformation
  15. Discussion of WKT concatenated coordinate operations
  16. Investigate a current BAG XML using BAG Explorer.
  17. Review of example of BoundCRS in pyproj.
  18. Discussion of Action Items and end of meeting.

Action items

  1. Make repo, add notes, links, and examples (xml, kinds of transformations NOAA wants to store as part of CRS) - Glen
  2. Confirm BAG lib operation with the CRS fields as they exist - Glen