json_schema: {
      "title": "Navigation Constraint",
      "type": "object",
      "$schema": "http://json-schema.org/draft-04/schema",
      "description": "Object determining whether the camera is constrained to navigate only above, or also under the ground surface.",
      "properties": {
          "type": {
              "type": "string",
              "enum": [
                  "none",
                  "stayAbove"
              ]
          }
      },
      "required": [
          "type"
      ],
      "additionalProperties": false
  }