at.adsb.receiver.sighting

{
  "id": "at.adsb.receiver.sighting",
  "defs": {
    "main": {
      "key": "tid",
      "type": "record",
      "record": {
        "type": "object",
        "required": [
          "aircraft",
          "firstSeen",
          "lastSeen",
          "createdAt"
        ],
        "properties": {
          "track": {
            "type": "blob",
            "accept": [
              "application/json",
              "application/zstd"
            ],
            "maxSize": 2000000,
            "description": "Position track as a JSON array of at.adsb.flight.defs#position objects, optionally compressed. This is the receiver's partial view of the flight."
          },
          "qnhHpa": {
            "type": "string",
            "maxLength": 10,
            "description": "Altimeter setting (QNH) in hectopascals."
          },
          "squawk": {
            "type": "string",
            "maxLength": 4,
            "minLength": 4,
            "description": "Transponder squawk code (e.g. '2636')."
          },
          "aircraft": {
            "ref": "com.atproto.repo.strongRef",
            "type": "ref",
            "description": "Strong reference to the at.adsb.aircraft.identity record for this aircraft."
          },
          "callsign": {
            "type": "string",
            "maxLength": 8,
            "description": "Flight callsign as broadcast (e.g. 'UAL123')."
          },
          "category": {
            "type": "string",
            "maxLength": 4,
            "description": "ADS-B emitter category (e.g. 'A3' for large aircraft)."
          },
          "lastSeen": {
            "type": "string",
            "format": "datetime",
            "description": "When this receiver last detected the aircraft."
          },
          "createdAt": {
            "type": "string",
            "format": "datetime"
          },
          "firstSeen": {
            "type": "string",
            "format": "datetime",
            "description": "When this receiver first detected the aircraft."
          },
          "maxRangeNm": {
            "type": "string",
            "maxLength": 20,
            "description": "Furthest distance to this aircraft during the sighting, in nautical miles."
          },
          "messageCount": {
            "type": "integer",
            "minimum": 0,
            "description": "Total messages received from this aircraft."
          },
          "positionCount": {
            "type": "integer",
            "minimum": 0,
            "description": "Number of position reports received."
          },
          "finalAltitudeFt": {
            "type": "integer",
            "description": "Barometric altitude in feet at last detection."
          },
          "finalHeadingDeg": {
            "type": "string",
            "maxLength": 10,
            "description": "Ground track in degrees at last detection."
          },
          "initialAltitudeFt": {
            "type": "integer",
            "description": "Barometric altitude in feet at first detection."
          },
          "initialHeadingDeg": {
            "type": "string",
            "maxLength": 10,
            "description": "Ground track in degrees at first detection."
          },
          "finalGroundSpeedKts": {
            "type": "string",
            "maxLength": 10,
            "description": "Ground speed in knots at last detection."
          },
          "finalVerticalRateFpm": {
            "type": "integer",
            "description": "Vertical rate in feet per minute at last detection. Negative is descending."
          },
          "initialGroundSpeedKts": {
            "type": "string",
            "maxLength": 10,
            "description": "Ground speed in knots at first detection."
          },
          "initialVerticalRateFpm": {
            "type": "integer",
            "description": "Vertical rate in feet per minute at first detection. Negative is descending."
          }
        }
      },
      "description": "A receiver's sighting of an aircraft transit through its coverage area."
    }
  },
  "$type": "com.atproto.lexicon.schema",
  "lexicon": 1,
  "description": "A single receiver's sighting of an aircraft. Created when the aircraft leaves the receiver's coverage area. Feeder-authoritative — published immediately without waiting for the full flight to complete."
}