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)