| ADS-B | Automatic Dependent Surveillance–Broadcast; aircraft broadcasts carrying identity, position, velocity, and status |
| ADS-R | ADS-B Rebroadcast; ground retransmission of ADS-B from another link |
| Beast | Framed binary format used to transport Mode S messages and signal metadata |
| BeastReduce+ | Bandwidth-reduced Beast output used for the airplanes.live connection |
| CPR | Compact Position Reporting, the latitude/longitude encoding used by ADS-B |
| dBFS | Decibels relative to digital full scale; relative receiver power rather than calibrated dBm |
| DF | Mode S downlink format number |
| Feeder UUID | Receiver identity assigned for the airplanes.live feed |
| ICAO hex | 24-bit aircraft address normally displayed as six hexadecimal characters |
| IQ samples | In-phase and quadrature radio samples produced by the SDR |
| LaunchAgent | A macOS user service managed by launchd |
| MLAT | Multilateration, a server-assisted position technique requiring precise timing and a configured client |
| Mode A/C | Legacy transponder identity and altitude replies without a Mode S CRC |
| Mode S | Selective secondary-surveillance-radar protocol used on 1090 MHz |
| readsb | The local decoder that owns the RTL-SDR and produces frames, aircraft JSON, and receiver statistics |
| RTL-SDR | Low-cost USB software-defined radio family based on the RTL2832U |
| SDR | Software-defined radio |
| TIS-B | Traffic Information Service–Broadcast; ground rebroadcast of surveillance targets |
| TC | ADS-B extended-squitter type code |
| UAT | Universal Access Transceiver on 978 MHz; not received by this 1090 MHz configuration |
| Uplink | Protected two-second HTTPS transfer from the Mac collector to the remote relay |