# at.adsb.broadcast.message

> Published by [adsb.at](https://lexicon.garden/identity/did:plc:32thk4eifx4ou6mxevswgjhg)

✓ This is the authoritative definition for this NSID.

## Description

A real-time aircraft state update, broadcast via at.adsb.broadcast.subscribeEvents. Ephemeral — not written to a PDS.

## Links

- [View on Lexicon Garden](https://lexicon.garden/lexicon/did:plc:32thk4eifx4ou6mxevswgjhg/at.adsb.broadcast.message)
- [Documentation](https://lexicon.garden/lexicon/did:plc:32thk4eifx4ou6mxevswgjhg/at.adsb.broadcast.message/docs)
- [Examples](https://lexicon.garden/lexicon/did:plc:32thk4eifx4ou6mxevswgjhg/at.adsb.broadcast.message/examples)

## Definitions

### `at.adsb.broadcast.message`

**Type**: `record`

Current state of a tracked aircraft as observed by a single receiver.

**Key**: `tid`

| Property | Type | Required | Description |
|----------|------|----------|-------------|
| `rc` | `integer` | No | Radius of containment in metres. Derived from NIC. |
| `nic` | `integer` | No | Navigation Integrity Category (0-11). Higher is more precise. |
| `rssi` | `string` | Yes | Received signal strength indicator in dBFS. |
| `seen` | `string` | Yes | Seconds since last message from this aircraft. |
| `squawk` | `string` | No | Transponder squawk code (e.g. '2636'). |
| `icaoHex` | `string` | Yes | ICAO 24-bit hex address (uppercased). |
| `seenPos` | `string` | No | Seconds since last position fix from this aircraft. |
| `aircraft` | `ref` → `com.atproto.repo.strongRef` | No | Strong reference to the at.adsb.aircraft.identity record for this aircraft. |
| `callsign` | `string` | No | Flight callsign as broadcast (e.g. 'UAL123'). |
| `position` | `ref` → `at.adsb.flight.defs#position` | No | Most recent position fix for this aircraft. |
| `messageCount` | `integer` | No | Total messages received from this aircraft in the current tracking session. |

## Raw Schema

```json
{
  "id": "at.adsb.broadcast.message",
  "defs": {
    "main": {
      "key": "tid",
      "type": "record",
      "record": {
        "type": "object",
        "required": [
          "icaoHex",
          "rssi",
          "seen"
        ],
        "properties": {
          "rc": {
            "type": "integer",
            "minimum": 0,
            "description": "Radius of containment in metres. Derived from NIC."
          },
          "nic": {
            "type": "integer",
            "maximum": 11,
            "minimum": 0,
            "description": "Navigation Integrity Category (0-11). Higher is more precise."
          },
          "rssi": {
            "type": "string",
            "maxLength": 10,
            "description": "Received signal strength indicator in dBFS."
          },
          "seen": {
            "type": "string",
            "maxLength": 10,
            "description": "Seconds since last message from this aircraft."
          },
          "squawk": {
            "type": "string",
            "maxLength": 4,
            "minLength": 4,
            "description": "Transponder squawk code (e.g. '2636')."
          },
          "icaoHex": {
            "type": "string",
            "maxLength": 6,
            "minLength": 6,
            "description": "ICAO 24-bit hex address (uppercased)."
          },
          "seenPos": {
            "type": "string",
            "maxLength": 10,
            "description": "Seconds since last position fix from this aircraft."
          },
          "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')."
          },
          "position": {
            "ref": "at.adsb.flight.defs#position",
            "type": "ref",
            "description": "Most recent position fix for this aircraft."
          },
          "messageCount": {
            "type": "integer",
            "minimum": 0,
            "description": "Total messages received from this aircraft in the current tracking session."
          }
        }
      },
      "description": "Current state of a tracked aircraft as observed by a single receiver."
    }
  },
  "$type": "com.atproto.lexicon.schema",
  "lexicon": 1,
  "description": "A real-time aircraft state update, broadcast via at.adsb.broadcast.subscribeEvents. Ephemeral — not written to a PDS."
}
```