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Python Mode-S Decoder

Project description

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

  • Automatic Dependent Surveillance - Broadcast (ADS-B) (DF17)
    • aircraft infomation that cotains: icao address, position, altitude, velocity (ground speed), and callsign, etc.
  • Mode-S Enhanced Surveillance (EHS) (DF20 and DF21)
    • additional information in response to SSR interogation, such as: true airspeed, indicated airspeed, mach number, track angle, heading, and roll angle, etc.

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

Source code

Checkourt and contribute to this open source project at:


Checkout source code, or install using pip:

pip install pyModeS


import pyModeS as pms

Core functions for ADS-B decoding:

pms.adsb.position(msg_odd, msg_even, t_odd, t_even)

Core functions for EHS decoding:

pms.ehs.icao(msg)       # icao address
pms.ehs.BDS(msg)        # Comm-B Data Selector Version

# for BDS version 2,0
pms.ehs.callsign(msg)   # Aircraft callsign

# for BDS version 4,0
pms.ehs.alt_mcp(msg)    # MCP/FCU selected altitude (ft)
pms.ehs.alt_fms(msg)    # FMS selected altitude (ft)
pms.ehs.alt_pbaro(msg)  # Barometric pressure (mb)

# for BDS version 5,0
pms.ehs.roll(msg)       # roll angle (deg)
pms.ehs.track(msg)      # track angle (deg)         # ground speed (kt)
pms.ehs.rtrack(msg)     # track angle rate (deg/sec)
pms.ehs.tas(msg)        # true airspeed (kt)

# for BDS version 6,0
pms.ehs.heading(msg)    # heading (deg)
pms.ehs.ias(msg)        # indicated airspeed (kt)
pms.ehs.mach(msg)       # MACH number
pms.ehs.baro_vr(msg)    # barometric altitude rate (ft/min)
pms.ehs.ins_vr(msg)     # inertial vertical speed (ft/min)

Some helper functions:

pms.df(msg)             # downlink format of a Mode-S message
pms.hex2bin(msg)        # convert hexadecimal string to binary string
pms.hex2int(msg)        # convert hexadecimal string to integer
pms.bin2int(msg)        # convert binary string to integer

Project details

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Filename, size & hash SHA256 hash help File type Python version Upload date
pyModeS-1.0.2-py2-none-any.whl (11.3 kB) Copy SHA256 hash SHA256 Wheel py2
pyModeS-1.0.2.tar.gz (9.8 kB) Copy SHA256 hash SHA256 Source None

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