Graphiti & Scratch
Small highly sensitive detectors are mounted on the rear windows of buses trains and trams. Audio analysis software (inside every DTI recorder) is used to detect and identify scratching noises whilst filtering out background noises associated with moving rolling stock carriages. A positive scratch detection event can be used to tag the recording or send out a vehicle message to the control room via 3G/4G so the authorities can locate the vehicle and catch the offenders in the act.
DTI Scratch Detection Released in 2007