Definition of "parametric_datum"

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_datum": {
  "type": "object",

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

  "properties": {
    "type": { "type": "string", "enum": ["ParametricDatum"] },
    "name": { "type": "string" },
    "anchor": { "type": "string" },
    "anchor_epoch": { "type": "number" }
    "conventional_RS": { "type": "string" }
    "publication_date": { "type": date }
    "$schema" : {},

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

    "remarks": {},
    "id": {}, "ids": {}
  },
  "required" : [ "name" ],
  "additionalProperties": false
},

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

"$comment": "[RL] 3x attributes missing."

Begin with the parametric_datum schema excerpt in this issue and the linked ProjJson v0-7 document. Compare the proposal with the repository’s current schema, resolve the usage and extent properties and the three noted missing attributes, and confirm the resulting definition matches the agreed specification.