Yesterday we posted about the command line rtl_acars ACARS decoder. Today on YouTube, Pawel Janowski has posted a video showing how to download, compile and run the rtl_acars.c code on Linux.
Pawel has also posted the compilation instructions on his blog (in Polish but the console commands are easy to discern from the text).
On the Osmocom mailing list, Andreas has posted his work on a console based ACARS decoder for the RTL-SDR. Check out the mailing list thread here, and original post here. The second post on the thread shows how to compile it under Linux. Andreas writes
I have combined “rtl_fm” with Thierry Leconte’s (GPL’ed) acarsdec library code and created “rtl_acars” which can directly decode ACARS flight info messages to the console. Confirmed to compile on OSX 10.6 (not possible for me to check if it also compiles under Windows and *nix). Feel free to add it as another proof of concept to your distro unless you consider it too much of a quick&dirty hack.
Only the source code is available, and you will need to compile it yourself. The code can be found here.
ACARS is an acronym for Aircraft Communications Addressing and Reporting System which is a digital communications system that aircraft use to send and receive short messages to and from ground stations.
Standard ACARS transmits at a frequency of 131.550 MHz, which is in the receivable range of the RTL-SDR. The RTL-SDR software radio can be used as a radio scanner for listening to these digital messages, and with the help of some decoding software, can be used to decode and display the messages. The messages you can receive will be from nearby aircraft and ground stations. Most messages will be unreadable data intended for computers, but you can find out what is flying near you by decoding the flight number and aircraft registration details sent with every message.
There is also HF ACARS, which is used for long distance communications. In this article the focus will be on VHF ACARS, as receiving HF ACARS is a little different.
YouTube user Superphish shows a timelapse over 5 hours of ACARS traffic and decoding using SDR# and decoding program acarsd. He used a J-Pole antenna. (2021 Update: please see note regarding acarsd no longer working as expected below in the tutorial)
