Install and Configure dumpvdl2

dumpvdl2 is a VDL Mode 2 message decoder and protocol analyzer. It is the recommended decoder for VDL2 and supports multiple simultaneous channels with flexible output options.

Installation on Debian/Ubuntu

Install dependencies

sudo apt-get install build-essential cmake git pkg-config libglib2.0-dev librtlsdr-dev

Install libacars (required)

git clone https://github.com/szpajder/libacars.git
cd libacars
mkdir build && cd build
cmake ../
make
sudo make install
sudo ldconfig

Build dumpvdl2

git clone https://github.com/szpajder/dumpvdl2.git
cd dumpvdl2
mkdir build && cd build
cmake ../
make
sudo make install

Optional build flags:

• -DRTLSDR=TRUE — RTL-SDR support (enabled by default if librtlsdr is found)
• -DMIRISDR=TRUE — Mirics SDR support
• -DSDRPLAY=TRUE — SDRplay support
• -DSOAPYSDR=TRUE — SoapySDR support
• -DSQLITE=TRUE — Aircraft database enrichment
• -DZMQ=TRUE — ZeroMQ output support (install libzmq3-dev first)

Quick install via script

An alternative to building from source is wiedehopf's install script:

bash -c "$(wget -q -O - https://raw.githubusercontent.com/wiedehopf/adsb-wiki/main/dumpvdl2-install.sh)"

Configuration

Basic usage

dumpvdl2 --rtlsdr 0 --gain 40 --correction 0 \
  --output decoded:json:udp:address=feed.airframes.io,port=5552 \
  --station-id MY-STATION-VDL2 \
  136975000

Key command-line options

Option	Description
--rtlsdr <device>	Use RTL-SDR device (by index or serial number)
--sdrplay <device>	Use SDRplay device
--soapysdr <device>	Use SoapySDR device
--gain <dB>	Tuner gain in dB
--correction <ppm>	Frequency correction in PPM
--centerfreq <freq>	Set center frequency (useful to avoid DC spike)
--station-id <id>	Station identifier for output messages
--output <spec>	Output configuration (see below)

Frequencies are specified as trailing arguments in Hz (e.g., 136975000) or with suffixes (136.975M).

Output configuration

dumpvdl2 uses a flexible output system with the syntax:

--output <what>:<format>:<transport>:<parameters>

Formats:

• text — Human-readable text
• json — JSON format (required for Airframes)

Transports:

• file:path=/path/to/file — Write to file (supports rotate=hourly or rotate=daily)
• udp:address=<host>,port=<port> — Send via UDP
• tcp:address=<host>,port=<port> — Send via TCP
• zmq:mode=<client|server>,endpoint=<endpoint> — ZeroMQ pub/sub

Multiple --output flags can be used simultaneously.

Feeding to Airframes

dumpvdl2 --rtlsdr 0 --gain 40 \
  --output decoded:json:udp:address=feed.airframes.io,port=5552 \
  --station-id MY-STATION-VDL2 \
  136650000 136700000 136800000 136975000

You can feed to Airframes and log locally at the same time:

dumpvdl2 --rtlsdr 0 --gain 40 \
  --output decoded:json:udp:address=feed.airframes.io,port=5552 \
  --output decoded:text:file:path=/var/log/vdl2.log,rotate=daily \
  --station-id MY-STATION-VDL2 \
  136650000 136700000 136800000 136975000

Common VDL2 Frequencies

North America

Frequency	Provider
136.650 MHz	ARINC
136.700 MHz	ARINC
136.800 MHz	SITA
136.975 MHz	Common Signalling Channel (worldwide)

Recommended: 136650000 136700000 136800000 136975000

Europe

Frequency	Provider
136.725 MHz	ARINC
136.775 MHz	SITA
136.825 MHz	ARINC
136.875 MHz	SITA
136.975 MHz	Common Signalling Channel (worldwide)

Recommended: 136725000 136775000 136825000 136875000 136975000

Asia-Pacific

Frequency	Provider
136.700 MHz	ARINC
136.750 MHz	SITA
136.975 MHz	Common Signalling Channel (worldwide)

Middle East

Frequency	Provider
136.750 MHz	SITA
136.975 MHz	Common Signalling Channel (worldwide)

tip

136.975 MHz is the VDL2 Common Signalling Channel (CSC) and should always be included. Check the Airframes stations page to see what frequencies work for feeders in your area.

Running as a Service

sudo tee /etc/systemd/system/dumpvdl2.service << 'EOF'
[Unit]
Description=dumpvdl2 VDL2 decoder
After=network.target

[Service]
Type=simple
ExecStart=/usr/local/bin/dumpvdl2 --rtlsdr 0 --gain 40 --output decoded:json:udp:address=feed.airframes.io,port=5552 --station-id MY-STATION-VDL2 136650000 136700000 136800000 136975000
Restart=always
RestartSec=5

[Install]
WantedBy=multi-user.target
EOF

sudo systemctl daemon-reload
sudo systemctl enable dumpvdl2
sudo systemctl start dumpvdl2

Verifying Your Feed

Visit the Airframes stations page and search for your station ID. VDL2 typically produces a higher volume of messages than VHF ACARS, so you should see activity fairly quickly near busy airports.