milastdbx commented on code in PR #560: URL: https://github.com/apache/parquet-format/pull/560#discussion_r3078886075
########## 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`: `{"$schema": "https://proj.org/schemas/v0.7/projjson.schema.json","type": "GeographicCRS","name": "NAD83 (CRS83)","datum": {"type": "GeodeticReferenceFrame"...` Review Comment: Given that these are only a suggested formats - not sure how to word this without sounding restrictive. Readers would have to choose what formats they support - whether its superset of suggested or subset of suggested formats. Algorithm for suggested formats would be: 1) If string starts with `projjson:` - go with `projjson:<key_name>` 2) If string starts with `srid:` - go with `srid:<identifier>` 3) Try parse string as a projjson - if it fails 4) Load string as `authority:code` ########## Geospatial.md: ########## @@ -44,8 +44,12 @@ locations on Earth. The default CRS `OGC:CRS84` means that the geospatial features must be stored in the order of longitude/latitude based on the WGS84 datum. -Custom CRS can be specified by a string value. It is recommended to use an -identifier-based approach like [Spatial reference identifier][srid]. +Non-default CRS values are specified by any string that uniquely identifies a coordinate reference system associated with this type. +To maximize interoperability, suggested (but not limited to) formats for CRS are: +* `<projjson>` - A complete CRS definition embedded directly using the [PROJJSON](https://proj.org/en/stable/specifications/projjson.html) specification. Example for `OGC:CRS83`: `{"$schema": "https://proj.org/schemas/v0.7/projjson.schema.json","type": "GeographicCRS","name": "NAD83 (CRS83)","datum": {"type": "GeodeticReferenceFrame"...` Review Comment: Do you think we should add this guidance ? -- 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]
