ADS-B Reception

“The universe is a pretty big place. If it’s just us, seems like an awful waste of space.”
― Carl Sagan, Contact

Automatic Dependent Surveillance-Broadcast (ADS-B)

ADS-B is a surveillance technology where aircraft use satellite navigation to determine their position and then broadcast this information periodically. This allows for real-time tracking of aircraft by ground stations and other aircraft.

Static Screenshot of authors ADSB system

Key Features:

  • Position Broadcasting: Aircraft transmit their location, altitude, speed, and other data.
  • Situational Awareness: Other aircraft can receive these broadcasts, improving their awareness of surrounding traffic and enabling self-separation.
  • RTL-SDR Compatibility: ADS-B signals can be readily received using inexpensive RTL-SDR (Software Defined Radio) dongles.


ADS-B System Components:

The ADS-B system comprises three primary elements:

  1. Airborne Component: Aircraft equipment that generates and transmits ADS-B messages.
  2. Transport Protocol: The communication method used, such as 1090ES (1090 MHz Extended Squitter), 978 MHz UAT (Universal Access Transceiver), or VHF (VDL mode 2 or 4).
  3. Ground Infrastructure/Receiving Subsystem: Ground stations or other aircraft that receive and process ADS-B data.


Setting up an ADS-B Receiver with RTL-SDR:

To create a basic ADS-B air radar using an RTL-SDR, you’ll need:

  • An RTL-SDR dongle (R820T or R820T2 recommended for 1090 MHz).
  • A Sawbird Low Noise Amplifier
  • A 1090 MHz vertically polarized antenna.
  • Software to decode ADS-B signals.
  • Software to display the aircraft data on a map.
  • I am running a Raspberry Pi 4 to handle all the decoding
  • New (2/2025) to the project was to replace the RTL-SDR dongle with a Flycatcher PI hat with built in RTL-SDR. Only required replacing the dongle with the PI hat and changing the antenna connector, nice and compact!


Note: Numerous online tutorials provide detailed instructions for setting up an ADS-B receiver. Instead of duplicating those, here is a list of resources.

Looking for hardware recommendations?? Have a look here at my Tried and Tested hardware – SDR’s Pi’s, Connectors, Antenna’s, and more.

Click here: USRadioguy Virtual Radar to access my live air traffic display. This system features enhanced visualization with my own geostationary weather satellite imagery. If the feed is down, I’m likely performing system maintenance. The data is acquired via a Raspberry Pi running FlightRadar24, and also shared with these services:

An MLAT (Multilateration) feeder map is a tool that visualizes the network of receivers, also known as feeders, which contribute data to multilateration systems. These systems calculate the position of aircraft that do not have ADS-B transponders by measuring the time difference of arrival (TDOA) of signals at multiple receivers. The map shows the locations of these feeders and provides information about their synchronization and the quality of their connections.

I then pipe that data from the PI Aware system via TCP into my Virtual Radar System, which then plots and shows the aircraft that my antenna system can pick up.

My current feed on adsbexchange

Best of all, almost all of this software is open-source, which usually means free!