Milwaukee already has this system in place. A transponder is required to be on and mode C for all aircraft on the ground... in addition to all ground equipment such as fire trucks ect.
If you remember the program called AFCAD. The display looks similar to that. it has a ground layout of the airport, and the aircraft are identified by their callsign if they were assigned a squawk code. or they show up as unknown. ground vehicle have a pre-set transponder to identify the type of the vehicle
