Air Traffic Control Fully Certified
Human-Machine Interface; Situational Awareness; Distraction; Confusion
ATC Issue All Types; Deviation / Discrepancy - Procedural Other / Unknown; Ground Event / Encounter Other / Unknown
General None Reported / Taken
ATC Equipment / Nav Facility / Buildings
While working the Local Control position during the night time session; I noticed a call sign of an aircraft; moving along the center taxiway in between runways. I looked and observed that it wasn't an aircraft that matched up with the target. It was a vehicle. A discussion ensued between myself and a supervisor regarding the previous events concerning false targets popping up on the ASDEX [Airport Surface Detection Equipment; Model X] matching up with a previous departure. The target would end up being a city ops vehicle patrolling and carrying out their regular duties.  We've also noted that when it has occurred on other occasions; the educated guess was that the city ops vehicle was holding somewhere west of taxiway hotel in the dirt when the false target began to float across the ASDEX. On this particular occasion; the target didn't just float across the screen; it actually tagged up with the city ops vehicle and continued to keep the tag of Aircraft X. The Supervisor directed me to ask the city ops vehicle to turn off their squitter for 1 minute and to then turn it back on. The city ops vehicle complied and the Aircraft X tag remained attached to the vehicle. The only time the tag disappeared from the vehicle was when the city ops veered off into the safety area to avoid exiting aircraft who just landed. While the vehicle drove east along Taxiway Hotel; the Aircraft X tag remained connected to the vehicle. The obvious safety issue is when the weather is not VFR and we aren't able to confirm the immediate identity of the false target. I recommend the active investigation on the matter to determine whether it's a software; hardware; or any other type of issue that is causing these false targets. Maybe it's a city ops squitter issue and not an ASDEX issue.
A Tower Local Controller reported an airport operations vehicle tagged up on their ground radar with as an with an aircraft call sign.