gr-adsb

A GNU Radio out-of-tree (OOT) module to demodulate and decode Automatic Dependent Surveillance Broadcast (ADS-B) messages.

Features

• Supports many SDRs through GNU Radio and OsmoSDR (USRP, RTL-SDR, HackRF, BladeRF, etc)
• Supports various sample rates (2 Msps, 4 Msps, 6 Msps, etc). NOTE: Currently the sample rate must be an integer multiple of twice the symbol rate (2 Msym/s)
• Decoding of messages:
  • DF 0: Short Air-Air Surveillance (ACAS)
  • DF 4: Surveillance Altitude Reply
  • DF 5: Surveillance Identity Reply
  • DF 11: All-Call Reply
  • DF 16: Long Air-Air Surveillance (ACAS)
  • DF 17: ADS-B Extended Squitter
  • DF 18: CF=0,1,6 ADS-B Extended Squitter from Non-Mode S Transponders
  • DF 19: AF=0 Military ADS-B Extended Squitter
  • DF 20: Comm-B Altitude Reply
  • DF 21: Comm-B Identity Reply
• "Brief" stdout printing
• "Verbose" stdout printing

Usage

GNU Radio

There is an example GNU Radio Companion (.grc) flowgraph located at gr-adsb/examples/adsb_rx.grc. To use it, first open GNU Radio Companion $ gnuradio-companion and then open the .grc file.

Example "Brief" output:

 ICAO  Callsign  Alt  Climb Speed Hdng  Latitude    Longitude  Msgs Age
                 (ft) (ft/m) (kn) (deg)                             (s)
------ -------- ----- ----- ----- ---- ----------- ----------- ---- ---
a4da13 4349 60  16450  2240   360    9  39.0509491 -77.0292066   47  47
a72bda          27225                                           459   0
abe82c SWA3329  37000     0   481   39                            6 221
a00ca4 FDX1273  36025     0   407 -157  39.6801034 -77.9697876  273   0
a58a1b           1775                                             2   2
a1c534          24975 -2816   471   31                            9 233
a3cd6b          10575                                           542   0
a022ee FDX1234  28075  4352   455 -168  38.7769900 -78.8369141  168  23
a2dffe UAL1704   9725     0   307  -34  39.1294556 -78.0681909  114   0
aa8af7          16800     0   431   34  39.2041533 -76.5144043   59 110
a318ea          12075                                            27 257
aaf111 DAL1436  10525 -1152   303   -3  39.4307230 -76.9674072  921  55
ace5b6          16100                                             3   4
a50e47          29600                                           427  13
c00ec2          36975     0   413  103  37.9071614 -77.9345040  176   0
a8f63b FDX1679  25700  2240   419  175  38.9744110 -78.4300829  455  39
a8d62a FDX1630  34000     0   379  175  38.9746508 -78.4457397  126 234

Example "Verbose" Output:

----------------------------------------------------------------------
Datetime:       2019-07-25 21:41:55.426630 UTC
SNR:            18.50 dB
DF:             0 Short Air-Air Surveillance (ACAS)
Parity:         Passed (Recognized AA from AP)
AA:             a50e47
Units:          Standard
Altitude:       28800 ft

----------------------------------------------------------------------
Datetime:       2019-07-25 21:41:56.696635 UTC
SNR:            22.36 dB
DF:             4 Surveillance Altitude Reply
Parity:         Passed (Recognized AA from AP)
AA:             a50e47
FS:             0 No Alert, No SPI, In Air
DR:             0 No Downlink Request
IIS:            0
IDS:            0 No Information
Units:          Standard
Altitude:       28800 ft

----------------------------------------------------------------------
Datetime:       2019-07-25 21:41:56.716640 UTC
SNR:            8.76 dB
DF:             11 All-Call Reply
Parity:         Passed
CA:             5 Level >=2 Transponder, Can Set CA 7, In Air
AA:             a72bda

----------------------------------------------------------------------
Datetime:       2019-07-25 21:41:57.006685 UTC
SNR:            12.92 dB
DF:             17 Extended Squitter
Parity:         Passed
CA:             5 Level >=2 Transponder, Can Set CA 7, In Air
AA:             a8f63b
TC:             19 Airborne Velocity
Speed:          367 kn
Heading:        177 deg (W)
Climb:          3136 ft/min
Source:         Barometric Pressure Altitude Change Rate

----------------------------------------------------------------------
Datetime:       2019-07-25 21:41:57.249964 UTC
SNR:            16.79 dB
DF:             17 Extended Squitter
Parity:         Passed
CA:             5 Level >=2 Transponder, Can Set CA 7, In Air
AA:             aaf111
TC:             11 Airborne Position
Latitude:       39.4474182 N
Longitude:      -77.4949314 E
Altitude:       10775 ft

Webserver

To view the decoded planes and flight paths live in Google Maps, a webserver is included. The webserver can be started before or after the GRC flowgraph, but the webserver must be running to view the Google Maps webpage. The ZeroMQ block in the example flowgraph is required when using the webserver. Before running the webserver, be sure to install its dependencies.

NOTE: The webserver is a Python 2.7 application. Incompatibilities with Python 3 exist.

1. Open a terminal
2. $ cd gr-adsb/
3. $ cd web/
4. $ ./webserver.py or $ python2 webserver.py
5. Open a web browser
6. Browse to localhost:5000

SQLite Playback

Users can optionally record demodulated bursts to a SQLite database for storing or later replaying. This option depends on my other project gr-sqlite. Follow these instructions to install gr-sqlite.

To record bursts, enable the SQLite Sink in the adsb_rx.grc flowgraph. To replay those demodulated bursts later, run the adsb_playback.grc flowgraph.

Installation

GNU Radio is a dependency for gr-adsb. I recommend installing it with PyBOMBS. gr-adsb is currently compatible with GNU Radio 3.7 only. GNU Radio 3.8 support is in development.

Source Build

Build gr-adsb manually from source using the following procedure.

$ cd gr-adsb/
$ mkdir build
$ cd build/
$ cmake ../  # or cmake -DCMAKE_INSTALL_PREFIX=<path_to_install> ../
$ make
$ sudo make install
$ sudo ldconfig

Webserver Dependencies

If using the built-in Google Maps webserver, you'll need to install the following Python packages.

$ sudo pip install flask
$ sudo pip install flask-socketio
$ sudo pip install gevent
$ sudo pip install gevent-websocket