Module: PWN::SDR::Decoder::ADSB

Defined in:
lib/pwn/sdr/decoder/adsb.rb

Overview

Pure-Ruby ADS-B (1090 MHz Mode-S / 978 MHz UAT) activity detector.

Mode-S Extended Squitter is 2 Mbit/s PPM with 8/120 μs frames on a 2 MHz-wide channel — physically unrecoverable from GQRX's 48 kHz demodulated-audio tap. Rather than shell out to dump1090, this module runs Base.run_detector to characterise squitter density (bursts/sec, peak dBFS, floor) natively in Ruby. parse_line is retained for offline SBS-1 CSV analysis.

Constant Summary collapse

SBS_FIELDS = 
%i[
  msg_type tx_type session_id aircraft_id icao24 flight_id
  date_gen time_gen date_log time_log callsign altitude_ft
  ground_speed_kt track_deg lat lon vertical_rate_fpm squawk
  alert emergency spi on_ground
].freeze

Class Method Summary collapse

Class Method Details

.authors ⇒ Object

Author(s)

0day Inc. support@0dayinc.com



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# File 'lib/pwn/sdr/decoder/adsb.rb', line 62

public_class_method def self.authors
  "AUTHOR(S):\n  0day Inc. <support@0dayinc.com>\n"
end

.decode(opts = {}) ⇒ Object

Supported Method Parameters

PWN::SDR::Decoder::ADSB.decode( freq_obj: 'required - freq_obj returned from PWN::SDR::GQRX.init_freq' )



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# File 'lib/pwn/sdr/decoder/adsb.rb', line 27

public_class_method def self.decode(opts = {})
  freq_obj = opts[:freq_obj]
  hz  = PWN::SDR.hz_to_i(freq: freq_obj[:freq])
  uat = hz.between?(977_000_000, 979_000_000)
  PWN::SDR::Decoder::Base.run_detector(
    freq_obj: freq_obj,
    protocol: uat ? 'ADSB-UAT978' : 'ADSB-1090ES',
    note: '2 Mbit/s PPM squitters exceed the 48 kHz audio-tap Nyquist limit; native mode reports squitter-burst density only. Feed captured SBS-1 CSV to .parse_line for full field decode.',
    describe: proc { |b| { modulation: 'PPM', frame_len_us: 120, classification: b[:duration_ms] < 5 ? 'squitter' : 'interrogation-train' } }
  )
end

.help ⇒ Object

Display Usage for this Module



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# File 'lib/pwn/sdr/decoder/adsb.rb', line 68

public_class_method def self.help
  puts "USAGE (ruby-native detector, no external binaries):
    #{self}.decode(
      freq_obj: 'required - freq_obj returned from PWN::SDR::GQRX.init_freq'
    )

    #{self}.parse_line(line: 'MSG,3,1,1,ABCDEF,1,...')

    #{self}.authors
  "
end

.parse_line(opts = {}) ⇒ Object

Supported Method Parameters

PWN::SDR::Decoder::ADSB.parse_line(line: 'MSG,3,1,1,ABCDEF,...')



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# File 'lib/pwn/sdr/decoder/adsb.rb', line 42

public_class_method def self.parse_line(opts = {})
  line = opts[:line].to_s
  return { protocol: 'ADSB-UAT', summary: line.strip } unless line.start_with?('MSG,')

  f   = line.split(',', -1)
  out = { protocol: 'ADSB' }
  SBS_FIELDS.each_with_index { |k, i| out[k] = f[i] unless f[i].to_s.empty? }
  bits = []
  bits << "ICAO=#{out[:icao24]}" if out[:icao24]
  bits << "CS=#{out[:callsign].to_s.strip}" if out[:callsign]
  bits << "ALT=#{out[:altitude_ft]}ft" if out[:altitude_ft]
  bits << "POS=#{out[:lat]},#{out[:lon]}" if out[:lat] && out[:lon]
  bits << "GS=#{out[:ground_speed_kt]}kt" if out[:ground_speed_kt]
  bits << "SQK=#{out[:squawk]}" if out[:squawk]
  out[:summary] = "ADSB #{bits.join(' ')}".strip
  out
end