It sounds like the script has someone on the ground trying to work out what the aircraft is doing by looking at the airspeed? In which case they need to know both the airspeed and the ground speed to work out if the plane is climbing (assuming the pilot isn't messing with the throttle). How do they know airspeed if there is a compatibility issue with the electronics? If they have the ground speed from radar why can't they see what the plane is doing height wise? .