Simurgh

A Mode-S "BEAST" TCP decoder server.

Mostly an experiment to understand the raw binary "BEAST" signal format (see "Further Reading" for links about the format), and an excuse to learn Go. Don't use this for anything real.

© 2016-2017 Mike Tigas, all rights reserved. See license information.

Building / Installation

You need Go. Download & set it up using the instructions here; minimally, you need to install the Go tools (and the tools in your $PATH) and ensure that you have a $GOPATH set.

Then:

go get github.com/mtigas/simurgh

Now you'll have a binary at $GOPATH/bin/simurgh.

Make sure $GOPATH/bin is on your $PATH, or copy $GOPATH/bin/simurgh to somewhere like /usr/local/bin/.

Usage

1. You need a dump1090 server running.

2. Launch the simurgh listener by running simurgh. There are also some flags you can use:

   -baseLat float
       latitude used for distance calculation (default 40.77725)
   -baseLon float
       longitude for distance calculation (default -73.872611)
   -bind string
       ":port" or "ip:port" to bind the server to (default "127.0.0.1:8081")
   -sortMode uint
       0: sort by time, 1: sort by distance, 3: sort by air (default 1)
   

   i.e. simurgh --baseLat 40.68931 --baseLon "-74.04464" if you're receiving data from the Statue of Liberty(???)

3. Given that dump1090 is running on the same machine as this program,

   nc 127.0.0.1 30005 | nc 127.0.0.1 8081
   

   will pipe the appropriate network data in and you should see some basic aircraft output, not unlike dump1090’s "interactive mode". Something like:

   ICAO    Callsign    Location                Alt     Distance  Time
   a64d4d              40.631104,-73.874329^   2450    5.36
   a7ad0d  JBU839      40.519043,-73.865479^   7050    11.89
   a03765  AAL125      40.630646,-73.726013^   9450    12.54
   0c6030  BWA17       40.460999,-73.608704    4875    23.59
   aa4252              40.957535,-74.260986^?  21425   25.09?    27…
   ae0449  BALSA76     40.287689,-73.836365^   35000   27.59
   ac7b1b  JBU1503     40.431381,-73.503662    13650   29.22
   a099a7              40.865204,-73.195496?   18800   41.96?    22…
   a74923              40.950623,-73.106506^   18450   48.37
   a9f2c6              40.313828,-73.042053    22750   54.23
   acc6d1  AAL1313     40.804138,-72.314026    30850   86.49
   

   Output is updated constantly. Aircraft with location data older than 10sec are marked with a ?, and a timer eventually appears. Old aircraft (45sec) are discarded from the on-screen list.

   Aircraft where we have received network-assisted multilateration (to improve location data) are marked with ^; this data often comes back down from FlightAware if your dump1090 instance was installed with the "piaware" packages (i.e. piaware-config, et. al.) To receive MLAT data, your receiver needs to have an accurate location set on your "My ADS-B" FlightAware page.

Further Reading

• Information about the BEAST data format (see "Binary Format").
• The BEAST format only encapsulates the raw Mode-S data in TCP. Some Mode-S reference:
  • Wikipedia: Aviation transponder interrogation modes
  • Wikipedia: Secondary surveillance radar#Mode S
• dump1090 is one of several applications that accepts BEAST input (port 30004 or 31004) and generates BEAST output (30005), and is a good reference point:
  • portions of simurgh are based on the dump1090 mode s decoder implementation