Python library for Mode-S message decoding. Two separate methods are implemented to decode the following messages:

  • Automatic Dependent Surveillance – Broadcast (ADS-B) (DF17)
    • aircraft information that contains: ICAO address, position, altitude, velocity (ground speed), callsign, etc.
  • Mode-S Enhanced Surveillance (EHS) (DF20 and DF21). Additional information in response to SSR interrogation, such as: true airspeed, indicated airspeed, mach number, wind, temperature, etc.
    • BDS 2,0 Aircraft identification
    • BDS 2,1 Aircraft and airline registration markings
    • BDS 4,0 Selected vertical intention
    • BDS 4,4 Meteorological routine air report
    • BDS 5,0 Track and turn report
    • BDS 5,3 Air-referenced state vector
    • BDS 6,0 Heading and speed report

A detailed manual on Mode-S decoding is published by the author, at:

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