{
"id": "at.adsb.datalink.message",
"defs": {
"main": {
"key": "tid",
"type": "record",
"record": {
"type": "object",
"required": [
"protocol",
"capturedAt",
"createdAt"
],
"properties": {
"label": {
"type": "string",
"maxLength": 2,
"description": "ACARS message label (two-character code indicating message type)."
},
"icaoHex": {
"type": "string",
"maxLength": 6,
"description": "ICAO 24-bit aircraft address in hexadecimal, if identifiable."
},
"callsign": {
"type": "string",
"maxLength": 8,
"description": "Flight callsign as identified in the message."
},
"position": {
"ref": "at.adsb.flight.defs#position",
"type": "ref",
"description": "Aircraft position at the time of the message, if included."
},
"protocol": {
"type": "string",
"maxLength": 256,
"description": "Datalink protocol the message was received on.",
"knownValues": [
"at.adsb.datalink.message#acars",
"at.adsb.datalink.message#vdl2",
"at.adsb.datalink.message#hfdl"
]
},
"sublabel": {
"type": "string",
"maxLength": 4,
"description": "ACARS sublabel for further message classification."
},
"createdAt": {
"type": "string",
"format": "datetime"
},
"capturedAt": {
"type": "string",
"format": "datetime",
"description": "When the message was received by the station."
},
"messageText": {
"type": "string",
"maxLength": 20480,
"description": "Decoded message content.",
"maxGraphemes": 2048
},
"receiverDid": {
"type": "string",
"format": "did",
"description": "DID of the receiver that captured this message."
},
"frequencyMhz": {
"type": "string",
"maxLength": 20,
"description": "Frequency the message was received on, in MHz (e.g. '131.550')."
},
"registration": {
"type": "string",
"maxLength": 10,
"description": "Aircraft registration, if identifiable from the message."
},
"groundStation": {
"ref": "#groundStationInfo",
"type": "ref",
"description": "Ground station involved in the communication, if identifiable."
}
}
},
"description": "A captured aircraft datalink message."
},
"groundStationInfo": {
"type": "object",
"properties": {
"id": {
"type": "string",
"maxLength": 32,
"description": "Ground station identifier (e.g. HFDL station ID, VDL2 ground station address)."
},
"name": {
"type": "string",
"maxLength": 640,
"description": "Human-readable ground station name (e.g. 'Shannon', 'Reykjavik').",
"maxGraphemes": 64
},
"location": {
"ref": "community.lexicon.location.geo",
"type": "ref",
"description": "Geographic position of the ground station."
}
},
"description": "Identification of the ground station involved in the datalink communication."
}
},
"$type": "com.atproto.lexicon.schema",
"lexicon": 1,
"description": "A captured aircraft datalink message (ACARS, VDL2, or HFDL). These are low-volume, high-value records that represent individual communications between aircraft and ground stations."
}