NAME

       modes_rx: - Gnuradio Mode-S/ADS-B receiver

SYNOPSIS

       modes_rx [options] [options]

OPTIONS

       -h, --help
              show this help message and exit

       -l LOCATION, --location=LOCATION
              GPS coordinates of receiving station in format xx.xxxxx,xx.xxxxx

       -a REMOTE, --remote=REMOTE
              specify additional servers from which to take data in format tcp://x.x.x.x:y,tcp://....

       -n, --no-print
              disable printing decoded packets to stdout

       -K KML, --kml=KML
              filename for Google Earth KML output

       -P, --sbs1
              open an SBS-1-compatible server on port 30003

       -m MULTIPLAYER, --multiplayer=MULTIPLAYER
              FlightGear server to send aircraft data, in format host:port

              Receiver setup options:

       -s SOURCE, --source=SOURCE
              Choose source: uhd, osmocom, <filename>, or <ip:port> [default=uhd]

       -t PORT, --tcp=PORT
              Open a TCP server on this port to publish reports

       -R SUBDEV, --subdev=SUBDEV
              select USRP Rx side A or B

       -A ANTENNA, --antenna=ANTENNA
              select which antenna to use on daughterboard

       -D ARGS, --args=ARGS
              arguments to pass to radio constructor

       -f FREQ, --freq=FREQ
              set receive frequency in Hz [default=1090000000.0]

       -g dB, --gain=dB
              set RF gain

       -r RATE, --rate=RATE
              set sample rate [default=4000000.0]

       -T THRESHOLD, --threshold=THRESHOLD
              set pulse detection threshold above noise in dB [default=7.0]

       -p, --pmf
              Use pulse matched filtering [default=False]

       -d, --dcblock
              Use a DC blocking filter (best for HackRF Jawbreaker) [default=False]

DESCRIPTION

       A  Qt  Graphical  User Interface to display positions and status messages of aircraft as reported on 1090
       MHz.

       gr-air-modes implements a software-defined radio receiver for Mode S transponder signals, including ADS-B
       reports from equipped aircraft.

       Mode  S  is  the  transponder  protocol  used  in modern commercial aircraft.  A Mode S-equipped aircraft
       replies to radar interrogation  by  either  ground  radar  (secondary  surveillance)  or  other  aircraft
       ("Traffic  Collision  Avoidance  System",  or  TCAS). The protocol is an extended version of the Mode A/C
       protocol used in transponders since the 1940s.  Mode S  reports  include  a  unique  airframe  identifier
       (referred  to  as  the  "ICAO  number")  and  altitude (to facilitate separation control).  This receiver
       listens to the 1090MHz downlink channel; interrogation requests at 1030MHz are not received or decoded by
       this program.

       Automatic  Dependent  Surveillance-Broadcast  (ADS-B)  is  a  communication  protocol  using the Extended
       Squitter capability of the Mode S transport layer. There are other implementations (VDL Mode 2  and  UAT,
       for instance) but Mode S remains the primary ADS-B transport for commercial use. The protocol is:

       * Automatic: it requires no pilot input

       * Dependent: it is dependent on altimeter, GPS, and other aircraft
         instrumentation for information

       * Surveillance: it provides current information about the transmitting
         aircraft

       * Broadcast: it is one-way, broadcast to all receivers within range.

       ADS-B-equipped  aircraft  broadcast  ("squitter")  their  position,  velocity,  flight  number, and other
       interesting information to any receiver within range of the  aircraft.  Position  reports  are  typically
       generated once per second and flight indentification every five seconds.

       Implementation  of  ADS-B  is  mandatory  in  European  airspace  as well as in Australia. North American
       implementation is still voluntary, with a mandate arriving in 2020 via the FAA's "NextGen" program.

       The receiver modes_rx is written for  use  with  Ettus  Research  USRP  devices,  although  the  "RTLSDR"
       receivers  are  also  supported  via  the  Osmocom  driver. In theory, any receiver which outputs complex
       samples at at least 2Msps should work via the file input or UDP input options, or by means of a  Gnuradio
       interface. Multiple output formats are supported:

       * Raw (or minimally processed) output of packet data

       * Parsed text

       * SQLite database

       * KML for use with Google Earth

       * SBS-1-compatible output for use with e.g. PlanePlotter or Virtual
         Radar Server

       * FlightGear multiplayer interface for real-time display of traffic
         within the simulator

       Most  of  the common ADS-B reports are fully decoded per specification.  Those that are not are generally
       ones which are not commonly used.

       Should you receive a large number of reports which result in "not implemented" or "No handler"  messages,
       please use the -w option to save raw data and forward it to the author. To save time, note that receiving
       a small number of spurious reports is expected; false reports can be excluded  by  looking  for  multiple
       reports from the same aircraft (i.e., the same ICAO 6-digit hexadecimal number).

REQUIRES

       A  GNU  Radio supported receiver for RF capable of 2 Mbits/second sample rate and tuning to 1090 MHz. (Or
       captured data file or network connection to a data source.)

SEE ALSO

       The X GUI application modes_gui

       modes_gui(1)