Feeding ADS-B Networks
Tracking flights has become a fascinating and accessible hobby thanks to ADS-B (Automatic Dependent Surveillance-Broadcast) technology. Through ADS-B, we can collect flight data and contribute to global networks that make this information publicaly available. In this blog post, I’ll walk you through my ADS-B feed setup, who I feed, and why I’ve chosen these platforms.
Surveillance in Air Traffic Control
Surveillance is a critical component of Air Traffic Control (ATC) operations, enabling controllers to monitor and manage the movement of aircraft in controlled airspace. Sensors detect aircraft, calculate positions, gather other data (like identification and altitude), and present it on a situation display.
Common Surveillance Systems
- Primary Surveillance Radar (PSR)
- How it works: Sends radio pulses, which bounce off the aircraft and return to the radar site.
- Data provided: Position (bearing and distance). No altitude or identification.
- Use case: Basic detection; limited to “somethign is there.”
- Secondary Surveillance Radar (SSR)
- How it works: Based on military IFF. Sends coded pulses to transponders, which reply with squawk codes (Mode A) and pressure altitude (Mode C).
- Data provided: Position, identification (via squawk code), and altitude. Enhanced with Mode S, which adds a unique aircraft ID and selective interrogation.
- Use case: Standard ATC tool for controlled airspace.
- Automatic Dependent Surveillance-Broachast (ADS-B)
- How it works: Aircraft use onboard systems to calculate and broadcast position, altitude, and ID at regular intervals.
- Data provided: Accurate latitude, longitude, altitude, and Mode S ID.
- Use case: Modern, precise, and globally adopted for real-time tracking. The majority of amateur tracking
- Multilateration (MLAT)
- How it works: Uses time differences in signal arrival at multiple ground stations to triangulate position.
- Data provided: Position (calculated), often for aircraft without ADS-B.
- Use case: Cost-effective alternative for areas without radar. Amateur tracking of non-ADS-B aircraft
My ADS-B Feeding Setup
My ADS-B setup runs on a Lenovo mini PC with PRoxmox, hosting a virtual machine (VM) dedicated to feeding.
Proxmox Host
I use a Lenovo Thinkcentre M73P Tiny PC as my Proxmox host:
| Processor | Intel Pentium G3250T @ 2.80 GHz |
| Memory | 8GB DDR3, (2 Slots, SODIMM) |
| Storage | 120 GB SSD (Only 1 Bay) |
| Network | Intel I217-V, Gigabit |
| Network | Intel Wireless (Not Used) |
| USB Ports | 2 Front, 3 Rear |
| Display | VGA, Display Port |
This tiny PC has been running in my unheated, uninsulated garage for 18 months without issues. Proxmox idles at about 5% CPU utilization and uses 3.35 GB of memory when hosting only the ADS-B feeding VM. While I could use an LXC container for greater efficiency, the VM simplifies USB passthrough for my setup.
I chose Proxmox for its flexibility—it allows me to add more services in the garage without additional hardware. For instance, I plan to set up a LiveATC.net feed and connect my 433 MHz weather station in the near future. These can be hosted as virtual machines, eliminating the need for extra Raspberry Pis or similar devices.
Networking
The Proxmox host is connected via Ethernet to a UniFi Flex, housed in a Flex Utility Enclosure. The Flex connects wirelessly to my house using a UniFi Swiss Army Knife (UK-Ultra) with a Panel Antenna.
ADS-B Software
Software List
| Operating System | Ubuntu Server 24.04.1 LTS (Noble Numbat) |
| ADS-B Receiver | readsb by wiedehopf |
| Local Web Interface | tar1090 by wiedehopf |
| Stats Interface (Graphs) | graphs1090 by wiedehopf |
| Feed Client | Airplanes.live |
| Feed Client | FR24FEED |
| Feed Client | PIAWARE |
| Feed Client | ADSB.fi |
I rely on abcd567a scripts for installing PIAWARE on Ubuntu, as FlightAware’s official scripts are optimized for Raspberry Pi.
Information Flow
- Signal Reception: The outdoor antenna receives 1090 MHz signals and transmits them via coaxial cable to the ADS-B receiver in the garage.
- Singal Processing: The receiver filters, amplifies, and converts the singal to USB. The readsb software demodulates the singal into ADS-B messages.
- Local Output: tar1090 generates a local map view of aircraft dta, accessible on my network.
- Feed Clients: Each feed client sends data to its respective site. For MLAT, data is forwarded to MLAT servers, which calculate positions and integrate results into global maps.
ADS-B Bandwidth and Utilization
Bandwidth usage is minimal and manageable, even on a cellular connection or HamWAN. My 24-hour tracking stats:
| CPU Usage | ~3.5% |
| Memory Usage | ~1.4 GiB |
| Outgoing Bandwidth | Avg: 2.6 kB/sec, Max: 11.8 kB/sec |
| Aircraft Seen | Avg: 9, Max: 21 |
| Range | Peak: 185.5, Avg Max: 126.5 |
ADS-B Hardware
Hardware List
Antenna
The AirNav antenna is mounted 12 feet off the ground. Features:
- Tuned to 1090 MHz with 7dBi.
- Durable fibreglass and aluminum construction for outdoor use.
- 30 feet of coaxial cable to run indoors without external connections.
Alternative: DVB-T dongle antennas are tuned for UHF TV (470-860 MHz) and are less effective for 1090 MHz. Cutting these antennas to the appropriate length (~68.75 mm for 1090 MHz) can improve performance.
Receiver
The AirNav RadarBox FlightStick includes:
- A 1090 MHz band-pass filter.
- A 20.5 dBi amplifier for improved signal clarity and range.
Alternative: Generic RTL-SDR dongles can receive 1090 MHz singals but may suffer from weaker reception and more noise without filters and amplication.
Flight Tracking Networks
Who I Feed
Airplanes.live
I contribute data to Airplanes.live because it is a community-driven, open-source platform that offers unrestricted views of airspace. Unlike networks bound by FAA restrictions, which block private and military aircraft, Airplanes.Live provides full transparency. Their free API is useful for personal projects, and providing a feed helps support their operations. Airplanes.Live functions as the successor to ADSBx.
ADSB.fi
ADSB.fi was established as an alternative following the sale of ADSBx. It is a community-focused platform that continues to prioritize transparency and open data sharing
FlightRadar24 (FR24)
Feeding FlightRadar24 provides access to a free Business account, which includes historical flight data and API access. The API is robust and supports various personal projects and testing. This partnership facilitates access to detailed flight data.
FlightAware
FlightAware offers an Enterprise account to contributors, which includes access to detailed tracking data, historical flight records, and API features. The API is utilized for experimental projects, providing detailed information on flight history and routing.
Who I don’t feed
ADSBExchange.com
I previously contributed to ADSBExchange.com (ADSBx) but stopped after its sale to a private equity firm. Unlike other commercial networks like FlightAware and FlightRadar24, which offer contributors access to APIs and premium accounts, ADSBx provides no benefits in return. The shift in their operational model no longer aligns with my requirements.