The USRP can be used to receive Mode S transponder transmissions from modern aircraft. This includes ADS-B signals that broadcast information such as airframe position, speed, altitude, heading, ID, etc. In this implementation, GNU Radio performs the necessary DSP and demodulation of the packets (the decoder is known as 'Modez', and runs as a network server).
Building on top of GR-powered Modez, I have created a complete system ('AvMap') to decode Mode S, as well as ACARS messages (aviation 'text messages'), fuse the two data streams, and visualise local airspace in 3D over the Internet using Google Earth as the live, streaming front-end. The 'virtual cockpit view' uses current track data to re-position the camera so the user can imagine what the pilot is seeing while flying the plane at that moment (best during takeoff and landing). The ACARS messages are represented spatially on the map, and such a visualisation shows how/when certain performance/maintenance/operations messages are exchanged (including unusual ones, such as the state of the on-board lavatories).
With the appropriate antenna and filter, planes have been tracked at a distance of 514 km.
More detailed info/screen-shots can be found at: [ Ссылка ]
(This includes some interesting statistics/graphs that give insight into the performance of the decoder and general aviation flight rules.)
The system is running on pre-recorded replay feed due to relocation of receiver equipment: [ Ссылка ]
[ Ссылка ]
