at.adsb.receiver.sighting

{
  "$type": "com.atproto.lexicon.schema",
  "defs": {
    "main": {
      "description": "A receiver's sighting of an aircraft transit through its coverage area.",
      "key": "tid",
      "record": {
        "properties": {
          "callsign": {
            "description": "Flight callsign as broadcast (e.g. 'UAL123').",
            "maxLength": 8,
            "type": "string"
          },
          "createdAt": {
            "format": "datetime",
            "type": "string"
          },
          "firstSeen": {
            "description": "When this receiver first detected the aircraft.",
            "format": "datetime",
            "type": "string"
          },
          "icaoHex": {
            "description": "ICAO 24-bit aircraft address in hexadecimal (e.g. 'A1B2C3').",
            "maxLength": 6,
            "minLength": 6,
            "type": "string"
          },
          "lastSeen": {
            "description": "When this receiver last detected the aircraft.",
            "format": "datetime",
            "type": "string"
          },
          "maxRangeNm": {
            "description": "Furthest distance to this aircraft during the sighting, in nautical miles.",
            "maxLength": 20,
            "type": "string"
          },
          "messageCount": {
            "description": "Total messages received from this aircraft.",
            "minimum": 0,
            "type": "integer"
          },
          "positionCount": {
            "description": "Number of position reports received.",
            "minimum": 0,
            "type": "integer"
          },
          "track": {
            "accept": [
              "application/json",
              "application/zstd"
            ],
            "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.",
            "maxSize": 2000000,
            "type": "blob"
          }
        },
        "required": [
          "icaoHex",
          "firstSeen",
          "lastSeen",
          "createdAt"
        ],
        "type": "object"
      },
      "type": "record"
    }
  },
  "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.",
  "id": "at.adsb.receiver.sighting",
  "lexicon": 1
}