Any Unknown or Unlisted Aircraft Manufacturer
Air Traffic Control Fully Certified
Confusion; Situational Awareness
ATC Issue All Types
General None Reported / Taken
ATC Equipment / Nav Facility / Buildings
I was working DR-S. I was on Fusion; with all sensors appearing to operate normally. Atlanta was on a west operation. I noticed a VFR target approaching ATL from the NW; on a heading that would place it just off the departure end of the runways. I said something; and the Supervisor who was monitoring the approach area called the Tower immediately and asked if they saw anyone off the departure end of the runways. The track was indicating about 2;500 feet. I don't believe departures were stopped. The track briefly dropped; then re-acquired. I put a data block on the aircraft as 'TRK'; and hit <MF>Z; slew to check the RADAR data Fusion was using. The track was only being picked up by the MGE sensor. It was at an altitude that ATL's ASR and the Windy Hill ASR should've seen. The track continued to the South-Southeast at 2;500 feet for a while and then it disappeared entirely. MGE's RADAR throwing off bad tracks is not unusual; it's an old analog ASR that has a digitized feed. Documented problems with its feed have been made before; however; this is a little different; indicating a track RIGHT off the departure end of the runway at an altitude that put it in VERY close proximity to other aircraft. I didn't have any departures that were going to be an issue. This aircraft target very easily could've been real; an FTY departure that strayed into the ATL Class-B airspace. The MGE feed into Fusion needs to be turned off immediately and installation of the replacement system drastically accelerated.
A80 Controller described an apparent 'false' target near the departure end of ATL's runways utilizing 'fusion'; the reporter indicating the target may have been generated from the MGE sensor.