In the address bar, type: http://localhost:8080 (or http://127.0.0.1:8080 ). Hit enter.
: Before running Acarsdeco2, use a tool like SDR# to find your dongle's PPM frequency offset and optimal gain settings for the clearest signal. RTL-SDR Tutorial: Receiving Airplane Data with ACARS
A Windows Command Prompt window will open. If successful, it will display your RTL-SDR hardware details and initialize the selected frequencies. Accessing the Web Interface
The frequencies listed above ( 131550000 Hz, etc.) are common ACARS frequencies for North America and parts of Europe. Modify the --freq arguments based on your geographic location. Standard world frequencies include: Primary Worldwide frequency 131.725 MHz: Primary European frequency 131.825 MHz: Secondary European frequency 136.925 MHz: Primary European VDL Mode 2 / ACARS Step 3: Run the Application Acarsdeco2 Windows Download
Then run separate instances with their serial numbers:
Create a dedicated directory on your system, such as C:\Aviation\Acarsdeco2\ .
Let’s break down what each part does:
With great decoding power comes great responsibility. ACARS messages are not encrypted; they are broadcast in the clear. This is by design—efficiency and reliability trump confidentiality in air-to-ground datalinks. However, the ability to download and run Acarsdeco2 raises legitimate privacy and security questions. Sensitive operational messages (e.g., “Hijack code 7500” or medical emergency declarations) can be intercepted by anyone with the right software. While most messages are mundane (fuel reports, passenger counts), the potential for malicious use—stalking private jets, identifying cargo vulnerabilities, or social engineering—exists. Conversely, journalists and OSINT investigators use the same tool to track government aircraft, humanitarian missions, or environmental enforcement flights. The software itself is morally neutral; its Windows download is an enabler, not a judgment.
| Option | Description | |--------|-------------| | --device-serial 5 | Selects a specific SDR dongle by its serial number (useful if you have multiple dongles). | | --gain <value> | Sets the gain in dB (e.g., --gain 38.0 ). | | --freq-correction <ppm> | Sets oscillator correction in ppm (e.g., --freq-correction 65 ). | | --freq <Hz> | Adds an ACARS frequency. Repeat for up to three frequencies. | | --agc | Enables automatic gain control. | | --http-port <port> | Sets the port for the HTTP web server (default 8080). | | --outConnectUdp pp:127.0.0.1:9742 | Sends ACARS data to PlanePlotter on port 9742. | | --outServer ad2:30008 | Creates a TCP server on port 30008 that outputs data in SBS/Basestation format (for VRS). | | --logfile-sbs <path> | Writes a log file containing decoded messages. |
Acarsdeco2 supports multiple data output formats for integration with other software: RTL-SDR Tutorial: Receiving Airplane Data with ACARS A
Before running the software, your computer must recognize your RTL-SDR dongle using the WinUSB driver. Connect your RTL-SDR dongle to a USB port. Download and open (the standard SDR driver utility). Click Options and select List All Devices .
Unlike commercial software, Acarsdeco2 is an open-source command-line tool. There is no official "installer" or "setup.exe" hosted on a fancy website.
