Wednesday, May 16, 2018

..back to war! So, about the subject "flight mode" counter attack...let's just begin by defining that air traffic use a different TCP/IP protocol like VDL 2...this is something they don't except...if our communications are made in an obsolete (we might say it like this) SDR receiver... they will stay without no way, as their jammers are looking for typical Bluetooth inside the wireless network, or RF microwave...of jamming this system...here's how to install

The VDL2 (for "VHF Data Link mode 2") mode permits automatic transmissions between planes and ground stations, with an exchange of different pieces of information (and especially positions) through AVLC frames (I, UI, RR, XID...) very close to Packet frames. It is a short distance (400 km maximum) service proposed through a network of VHF ground stations (on 136.975 MHz mainly but also 136.875 MHz in Europe). It gradually replaces the ACARS mode.
  • The simplest way to decode this mode is to directly demodulate 8PSK frames by MultiPSK, with a SDR receiver (FUNcube Dongle, for example) connected to MultiPSK and the SDR interface started (on the Configuration screen). Adjust the SDR frequency on 136963 kHz and the waterfall frequency on 12 kHz (making it 136.975 MHz).
Or adjust the SDR frequency on 136863 kHz and the waterfall frequency on 12 kHz (making it 136.875 MHz).
The I/Q PSK demodulation will be done by Multipsk, so as the decoding.

  • However, a standard USB receiver can be used (both solutions are equivalent from a performance point of view). In this case, the reception central frequency must be shifted by 12 KHz, i.e the frequency on the USB receiver must be adjusted to 136.963 MHz (136963 KHz instead 136975 KHz). Of course, the SDR interface on Multipsk must not be started.

    The frequency must be very precisely adjusted (tolerance: +/50 Hz).
    "end quote"


    As of July 2016 the following 4 frequencies have been found to be active in Europe:
    136.725 MHz     dedicated to ARINC
    136.775 MHz     dedicated to SITA
    136.875 MHz     dedicated to SITA
    136.975 MHz     ARINC shared with SITA



    Connect the dongle to MultiPSK

    RTL dongle specific settings

    Setting the VDL2 Mode

    Setting the frequency

    Coarse frequency adjustment

    Fine frequency adjustment

    Connecting MultiPSK to Plane Plotter



    The VDL2 (for "VHF Data Link mode 2") mode permits automatic transmissions between planes and ground stations, with an exchange of different pieces of information (and especially positions) through AVLC frames (I, UI, RR, XID...) very…
    PLANEPLOTTER.PBWORKS.COM

    No comments: