Definition of "extent"

[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.

"extent": {
    "type": "array",
    "items": {
      "type": "object",
      "properties": {

"extent_description": { "type": "string" },

        "bbox": { "$ref": "#/definitions/bbox" },
        "extent_polygon": { "type": "array" },
        "vertical_extent": { "$ref": "#/definitions/vertical_extent" },
        "temporal_extent": { "$ref": "#/definitions/temporal_extent" }
       },

"required" : [ "extent_description", "bbox" ],

      "additionalProperties": false
    }
},

"$comment": "[RL] In ISO 19111 [OGC Abstract Spec Topic 2](from ISO 19115 [OGC Abstract Spec Topic 11]) an extent must contain at least one of the above properties; it may contain any or all of these properties. In ISO 19127 (geodetic registry) this is specialised: a description and a bbox are made mandatory, the remaining properties are optional. If this is considered best practice for geodetic registries, should it be considered as appropriate for CRS JSON?"