Definition of "prime_meridian"

[KRyden]

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.

"prime_meridian": {
  "type": "object",
  "properties": {
    "$schema" : { "type": "string" },
    "type": { "type": "string", "enum": ["PrimeMeridian"] },
    "name": { "type": "string" },
    "longitude": { "$ref": "#/definitions/value_in_degree_or_value_and_unit" },
    "id": { "$ref": "#/definitions/id" },
    "ids": { "$ref": "#/definitions/ids" }
  },
  "required" : [ "name" ],
  "allOf": [
    { "$ref": "#/definitions/id_ids_mutually_exclusive" }
  ],
  "additionalProperties": false
},

"$comment": "[RL] Topic 2 requires this as an attribute of geodetic reference frame but WKT2 makes it optional on the condition that value = the international reference meridian (Greenwich)."