I'm trying to write my own software that decodes signal from RTL Dongle connected on Raspberry Pi.
I'm actually having some success at this.
But what I can't find on line or figure out is how does programs such as Virtual Radar know to flag a mode-s message as being from a Military Aircraft? Is there a bit set in one of the DF (Downlink Format) messages? OR is Virtual Radio (and other programs) simply comparing the aircraft HexCode against a database of known Military hexcodes?
I know that DF 19 and DF 22 are reserved for military uses, do these contain data if the Mode-S message is from a military aircraft? I can say that DF 19 and DF 22 are empty in civil aircraft mode-s messages because I have a "C" program here just looking for those two Downlink Formats and so far they've been blank.
Any help would be appreciated,