It was a question in general. I am curious to know if someone with a clear view to the active areas of an airport would pick up vehicles transmitting ADS-B data, and if that would unfairly skew their statistics, since ground vehicles are not aircraft and should not be counted as such. Can you please tell us if this is the case? Or is the data being transmitted by ground vehicles known to the system and is therefore automatically excluded?
Ground vehicles are counted as “aircraft”. So are test signals, surface multilateration reference beacons, static obstacles, aircraft that are taxiing, aircraft that are being moved around on the ground, aircraft that are in maintenance, transponders that are being tested that aren’t even in an aircraft, balloons, space vehicles (!), etc. For “aircraft”, read “something that transmits Mode S” and interpret the stats accordingly.
Note that, most of the time, you can’t reliably tell that something is a ground vehicle from a Mode S message. There are specific cases where you can tell, but often the ADS-B data just doesn’t have the aircraft-category set.