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Author Topic: Beta of new ACARS decoding program available - Black Cat Absolute ACARS  (Read 498 times)

Offline ChrisSmolinski

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I've just released the first beta version of Black Cat Absolute ACARS, which decodes and displays VHF ACARS transmissions directly from SDR I/Q recording files, and is available for macOS and Windows.

Most traditional ACARS decoding programs only decode audio from one frequency at a time, some can handle a few frequencies. This means you're missing out and not receiving ACARS messages on the frequencies you're not monitoring.

And even with decoders that can handle multiple audio sources, you need to set up receivers in your SDR software for each frequency (up to whatever limit it has) along with multiple virtual audio cables to pass audio from the SDR software to the ACARS decoding program. What a mess.

This program does away with those limitations. It directly demodulates and decodes ACARS transmissions from SDR I/Q recording files, covering several MHz of bandwidth. It monitors the directory your SDR program saves I/Q files in, detects when a new file has been created, waits for that file to be finished written to, then opens it, decodes on all the selected ACARS frequencies, and then deletes the file, so your hard drive doesn't fill up. As new I/Q files are written every minute or two, there's minimal delay in seeing the ACARS messages.

You can even run this decoding program on a second computer, and access files on the computer with the SDR software creating writing the I/Q files over your local network.

In addition to displaying decoded messages, both on a per channel basis as well as all frequencies combined into one display, messages can be written to text logging files, either with a manually selected filename, or into rolling timestamped files.

Messages are also sorted by message type, aircraft tail number, flight number, and frequency. Display/logging of messages of specified types can also be disabled, reducing the amount of "clutter" of unwanted messages.

The Open Sky Network database file can also be used with this program, to display information about aircraft along with their messages.

Downloads available here: https://blackcatsystems.com/software/black_cat_absolute_acars_decoder_sdr_iq_file_decoding.html












Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 900 ft Horz skyloop / 500 ft NE beverage / 250 ft V Beam / 58 ft T2FD / 120 ft T2FD / 400 ft south beverage / 43m, 20m, 10m  dipoles / Crossed Parallel Loop / Discone in a tree

Offline ChrisSmolinski

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  • Marconi Class DXer
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  • Westminster, MD USA
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    • Black Cat Systems
I've just released a new beta of Black Cat Absolute ACARS. This has a few additions, the most substantial is a message scoring system to help both filter out the clutter of automated engineering data type messages, as well as highlighting messages most likely to be of interest.

Downloads available here: https://blackcatsystems.com/software/black_cat_absolute_acars_decoder_sdr_iq_file_decoding.html
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 900 ft Horz skyloop / 500 ft NE beverage / 250 ft V Beam / 58 ft T2FD / 120 ft T2FD / 400 ft south beverage / 43m, 20m, 10m  dipoles / Crossed Parallel Loop / Discone in a tree