ADS-B

ADS-B is a surveillance technology in which aircraft determine their own position using GPS and broadcast it, along with other flight data, on 1090 MHz.

ADS-B is a surveillance technology in which aircraft determine their own position using GPS and broadcast it, along with other flight data, on 1090 MHz. Ground stations and other aircraft can receive these broadcasts without any interrogation — it is a one-way broadcast.

ADS-B is mandated by aviation authorities in most of the world, meaning the vast majority of commercial and many general aviation aircraft are equipped.

Frequency

1090 MHz (Mode S Extended Squitter)

Hardware required

RTL-SDR USB dongle (~$25) — any RTL2832U-based device
1090 MHz antenna — included with most kits; a dedicated antenna improves range significantly

What data it contains

Each ADS-B message includes some or all of:

Field	Description
ICAO hex	Unique aircraft identifier
Callsign	Flight number or registration
Latitude / Longitude	GPS position
Altitude	Barometric (feet)
Ground speed	Knots
Track	Heading in degrees
Squawk	Transponder code
Vertical rate	Climb/descent rate (ft/min)

Decoder software

dump1090 and readsb are the two most common decoders:

# Debian/Ubuntu/Raspberry Pi
sudo apt install dump1090-fa   # FlightAware fork, widely used
# or
sudo apt install readsb         # Active development fork by wiedehopf

Both output SBS (BaseStation) format on TCP port 30003 by default — exactly what the AvioADSB feeder script connects to.

How the feeder works

The feeder script opens a TCP connection to 127.0.0.1:30003 (your local dump1090/readsb) and pipes the raw SBS stream to AvioADSB. No data transformation occurs — it is a raw byte relay.

Where it goes

Positions that pass the plausibility checks are merged into the network's live picture and served through the public API and the live map. Sharing ADS-B is what gives your account's API key the contributor tier.