{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://poseidat.org/schema/core/measurement/position.json",
  "title": "Position",
  "description": "A navigational position that can be used in an entry",
  "properties": {
    "latitude": {
      "description": "The latitude of the geographical location",
      "type": "number"
    },
    "longitude": {
      "description": "The longitude of the geographical location",
      "type": "number"
    },
    "course_made_good": {
      "description": "The direction in which the vessel is traveling, in degrees",
      "type": "number"
    },
    "speed_over_ground": {
      "description": "The velocity of the vessel in meters per second (m/s) over the ground",
      "type": "number"
    },
    "number_of_satellites": {
      "description": "The number of satellites used to calculate the position",
      "type": "number"
    },
    "fix_quality": {
      "description": "The fix quality as reported by an NMEA receiver (0 = invalid, 1 = GPS fix, 2 = DGPS fix)",
      "$ref": "https://poseidat.org/schema/enum/gnss-fix-quality.json"
    },
    "fix_type": {
      "description": "The type of GPS fix.",
      "$ref": "https://poseidat.org/schema/enum/gnss-fix-type.json"
    },
    "hdop": {
      "description": "Relative accuracy of horizontal position",
      "type": "number"
    },
    "antenna_altitude": {
      "description": "The number of meters above mean sea level of the receiver antenna",
      "type": "number"
    },
    "geoidal_separation": {
      "description": "Height of geoid above WGS84 ellipsoid in meters",
      "type": "number"
    },
    "dgps_data_age": {
      "description": "The age of the DGPS data in seconds",
      "type": "number"
    },
    "dgps_station_id": {
      "description": "The station id of the used DGPS reference station",
      "type": "number"
    }
  },
  "required": [
    "latitude",
    "longitude"
  ],
  "type": "object",
  "additionalProperties": false
}