Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 2.3
Confusion; Human-Machine Interface
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Air Traffic Control Separated Traffic
ATC Equipment / Nav Facility / Buildings
VA approaches in use.  RWY 28 L/R in use.  Aircraft X requests an ILS RWY 28R approach; not familiar with PDX.  Multiple jet arrivals mixed in.  Aircraft X was cleared for approach.  About 6 or 7 miles in trail of Aircraft X was an air carrier on a visual approach to RWY 28L.  The air carrier is over 200 knots ground speed.  Aircraft X is about 90 knots over ground.  We just started working on FUSION radar about 6 days ago.  New system for us.  Totally different than single site radar.  Anyway; when Aircraft X was about over the FAF I noticed his track was tracking south.  It did this for about 4 or five updates; then he was on the RWY 28L final approach course with the air carrier right behind him with a hundred knot overtake.  The Tower was talking to Aircraft X.  I called traffic to the air carrier; called the Tower to find out what Aircraft X was doing; and about to cancel approach clearance to the air carrier when Aircraft X's target jumped back on the RY 28R final.  Over a half mile target jump.  I watched it; everything looked good and I shipped the air carrier to Tower.  This scared me.  I am going to further investigate this with QA.  I believe Aircraft X never left the RWY 28R localizer and Fusion was screwing up and not working.  I need to see a replay on actual RADAR; single site.  It was such a big target jump.  But I don't know.  Aircraft X could have drifted south of course; but to the other localizer course the back in one or two updates. We need to find out whether this was a Fusion issue or if Aircraft X actually flew what I saw.
Reporter stated Fusion radar predicts where the aircraft might be; causing this type of jump.  Single site radar showed the aircraft never left the 28R final.  About 10 seconds of false data.
P80 Controller describes a large jump of an aircraft on final; possibly caused by fusion radar.