M-20 G Statesman
Air Traffic Control Fully Certified
Other / Unknown
ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance; Flight Crew Executed Go Around / Missed Approach
ATC Equipment / Nav Facility / Buildings
Air Carrier Y was on the ILS Runway 23L; approximately on a five mile final and had received landing clearance. M20E was issued take off clearance Runway 23L and assigned heading 160. Air Carrier Z was cleared for take off Runway 23R assigned heading 230. Meanwhile Air Carrier Y indicated he was going missed approach. During this time M20E; who was about 1 1/2 miles on the departure end; was tracking 230 degrees; instead of the 160 degrees assigned. I was working very hard to ensure that M20E was turning left to the 160 heading because I knew that if he wasn't; he would conflict with Air Carrier Z and Air Carrier Y. Air Carrier Z was issued a 270 heading to avoid a confliction with M20E and Air Carrier Y. Air Carrier Y was issued a 230 to avoid confliction with M20E and Air Carrier Z. This incident occurred in IFR conditions. It is my belief that because we were using FUSED/ADS-B RADAR; the targets were not tracking the accurate position of these aircraft. When M20E was issued a beacon code change; his target began to track right of course. When Air Carrier Y went missed approach; his target indicated an ISR or 'increase RADAR separation.' Prior to this incident; I have noticed many targets constantly moving left/right of course and a few that move backwards. Unless this problem is fixed; I recommend that we do not use FUSED/ADS-B.
An RDU Controller described a developing conflict when RARAR targets were not accurately tracking suggesting the FUSED/ADS-B RADAR was causing the anomaly.