A Look into ACARS Hub and How to Set It Up on Your SDR System

If you’re enthusiastic about software-defined radio (SDR), aircraft communications, or decoding digital signals, there’s an intriguing open-source project worth exploring: ACARS Hub, developed by the sdr-enthusiasts community. This project consolidates multiple aviation data sources—ACARS, VDLM2, HFDL, Iridium, and Inmarsat L-Band—into a powerful, containerized web platform. It caters not only to enthusiasts but also to anyone interested in gaining a deeper, human-readable understanding of the communications between aircraft and ground stations.

What Is ACARS Hub?

ACARS Hub is a Docker container designed to collect, parse, and visualize messages from a variety of aircraft communication systems. If you’ve ever used acarsdec, dumpvdl2, or dumphfdl, you’ll know that raw output can be technical and terse. ACARS Hub improves on this by enriching the decoded messages with data from the amazing team at Airframes.io, making messages easier to read and interpret.

It works across architectures—amd64, arm64, armv7, armv6, and even 386—making it perfect for devices like the Raspberry Pi.

What You’ll Need

To get started, you’ll need:

• A Linux system that can run Docker (a Raspberry Pi works great)
• One or more RTL-SDR dongles (at least one for ACARS, ideally a second for VDLM2)
• Docker and Docker Compose
• One or more SDR decoders (see below)

Decoding support includes:

• acarsdec (recommended: airframes fork)
• dumpvdl2 (preferred VDLM2 decoder)
• vdlm2dec
• dumphfdl
• satdump for Inmarsat
• gr-iridium toolkit for Iridium
• JAERO for L-band satellite decoding

All these decoders can run externally and push decoded JSON to ACARS Hub over UDP.

Ports and Connectivity

Here are the main ports you’ll deal with:

Using these, you can stream messages into the container and even pipe data out to other systems for further analysis or visualization.

Docker-Compose: The Fast Track Setup

Here’s a minimal working setup for your docker-compose.yaml:

services:
  acarshub:
    image: sdrenthusiasts/acarshub:latest
    ports:
      - 80:80
      - 5550:5550/udp
      - 5555:5555/udp
      - 5556:5556/udp
      - 5557:5557/udp
      - 5558:5558/udp
      - 15550:15550
      - 15555:15555
      - 15556:15556
      - 15557:15557
      - 15558:15558
    volumes:
      - acarshub_data:/run/acars
    environment:
      - ENABLE_WEB=true
      - ENABLE_ACARS=external
      - ENABLE_VDLM=external
      - DB_SAVEALL=false
volumes:
  acarshub_data:

This setup enables ACARS and VDLM2 processing, exposes the necessary ports, and stores data on a local volume.

Performance Tips

Running a database on something lightweight like a Raspberry Pi? You’ll want to:

• Mount /run/acars/ as a tmpfs to reduce SD card writes
• Set DB_SAVEALL=false to avoid storing uninformative messages
• Limit data retention by adjusting DB_SAVE_DAYS

Want better search speed? Temporarily enable AUTO_VACUUM=true to clean the database.

Enhancing Your Map with ADS-B Data

To display ADS-B targets on the ACARS Hub map:

1. Run tar1090 and readsb on the same host
2. Enable ADS-B in ACARS Hub with: - ENABLE_ADSB=true - ADSB_URL=http://tar1090/data/aircraft.json
3. Set your lat/lon for correct range rings

You’ll be able to click aircraft on the map and see related messages.

Make the Data Accurate for Your Region

Airline codes can be tricky. If you notice callsigns mapping incorrectly (e.g. UPS showing up as BahamasAir), you can fix them locally using the IATA_OVERRIDE environment variable. Example:

IATA_OVERRIDE=UP|UPS|United Parcel Service;US|AAL|American Airlines

Web Interface & Tricks

ACARS Hub has a responsive web UI on port 80. You can:

• Press p on the Live Messages page to pause auto-scroll
• Use the search page to filter messages by keyword or callsign
• Connect other tools or visualizers to exposed JSON ports like 15555 (VDLM2) or 15550 (ACARS)

Future Developments

The project’s active and rapidly evolving. Upcoming features include:

• A revamped UI
• Desktop apps
• Improved message matching between ACARS and ADS-B

Get Help or Contribute

ACARS Hub is open-source and community-driven. You can:

• Raise issues or contribute code on GitHub
• Join the Discord server for support and ideas

Whether you’re a seasoned SDR hobbyist or new to decoding, ACARS Hub makes it easier than ever to monitor real-world aircraft communication with real-time visualization and analysis.

Visit https://github.com/sdr-enthusiasts/docker-acarshub