What is the source for the flight data shown on in-flight entertainment systems? This question which claims that an altitude of 55,000 ft. was observed on a passenger's in-flight entertainment system on an Emirates B777 made me wonder: What are the normal sources of information for the flight data displayed on passenger IFE systems?

Of particular interest are the common sources for the following information:


Altitude (Is this a pressure altitude? Indicated altitude? A GPS-measured altitude? A radio-altimeter-measured absolute altitude?)
Speed (This seems to typically be true ground speed, which I'd assume comes from GPS, but any further insight would be appreciated)
Latitude/Longitude position (Is this from GPS? INS? radionav? some combination?)
Wind speed
I work on these panels which get the data (both IFE and cockpit display panels for a big OEM and there are very few in the world :)). This is all Air data systems which are providing all the data. We get this data from various sensors placed inside the cockpit or on aircraft exterior including wings and tail. Their are different kind of data transmission buses like ARINC which transmit that data then the required data is fed to IFE system through a protocol but most crucial data like data coming from Weather Radar etc is kept for Pilot usage and is displayed on the cockpit display panels.

For your question Altitude, elevation. azimuth there are some radars in the aircraft which gives that data and some of these radars measure and send this data using CAN protocol with very high speed varying from 40ms to 100ms.