mkaravel commented on code in PR #560: URL: https://github.com/apache/parquet-format/pull/560#discussion_r3081918551
########## Geospatial.md: ########## @@ -44,8 +44,12 @@ locations on Earth. The default CRS `OGC:CRS84` means that the geospatial features must be stored in the order of longitude/latitude based on the WGS84 datum. -Custom CRS can be specified by a string value. It is recommended to use an -identifier-based approach like [Spatial reference identifier][srid]. +Non-default CRS values are specified by any string that uniquely identifies a coordinate reference system associated with this type. +To maximize interoperability, suggested (but not limited to) formats for CRS are: +* `<projjson>` - A complete CRS definition embedded directly using the [PROJJSON](https://proj.org/en/stable/specifications/projjson.html) specification. Example for `OGC:CRS83`: `{"$schema": "https://proj.org/schemas/v0.7/projjson.schema.json","type": "GeographicCRS","name": "NAD83 (CRS83)","datum": {"type": "GeodeticReferenceFrame"...` Review Comment: I would also leave it to the readers to decide if they want to do a full parse on the PROJJSON string. Regarding how to parse the field overall, I think what @milastdbx is basically the logic. I do not see any ambiguity. The PROJJSON string should start with `{` anyways which is different from any other option listed. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
