Definition of "parametric_crs" and "paramatric_cs" (Missing)

NOTE: Markdown does not support highlighting in color, so bold/italic has been used to highlight the material being discussed. This issue is extracted from the document submitted by Roger Lott at https://github.com/opengeospatial/CRS-JSON-Encoding/blob/main/ProjJson%20v0-7%20RL%202024-06-16.docx for discussion at the CRS SWG meeting OGC held during the Montreal June 2024 TC meeting.

"parametric_crs": {
  "type": "object",

"allOf": [{ "$ref": "#/definitions/object_usage" }],

  "properties": {
    "type": { "type": "string", "enum": ["ParametricCRS"] },
    "name": { "type": "string" },
    "datum": { "$ref": "#/definitions/parametric_datum" },

"coordinate_system": { "$ref": "#/definitions/coordinate_system" }, STRIKE THIS LINE
"coordinate_system": { "$ref": "#/definitions/parametric_cs" },

    "$schema" : {},

"scope": {},
"area": {},
"bbox": {},
"vertical_extent": {},
"temporal_extent": {},
"usages": {},

    "remarks": {},
    "id": {}, "ids": {}
  },

"required" : [ "name", "datum", "coordinate system" ],

  "additionalProperties": false
},

"$comment": "[RL] See comment regarding usage under compound_crs."

"$comment": "[RL] A parametric CRS should be constrained to having a parametric_cs."

"$comment": "[RL] In 19111/Topic 2, a parametric CRS may have a datum ensemble rather than a datum. 19162/WKT2 spec does not offer the option. Should CRS JSON?"

"$comment": "[RL] A parametric CRS must have a datum (or a datum_ensemble, see previous comment). The schema would be clearer if this was included in the required list."

"parametric_cs": { }

"$comment": "[RL] Definition to be completed. The definition would constrain a parametric CS to have 1 axis."

Start with the schema fragments quoted in issue #39 and compare them with ProjJson v0-7 RL 2024-06-16.docx. Review the open questions about parametric CRS datum choices, required properties, usage metadata, and the one-axis parametric coordinate system. The work is done when the parametric_crs and parametric_cs definitions are completed and the agreed constraints are represented consistently.