Narrative:

While working LC2 I had up to 8 aircraft in the VFR traffic pattern. During that time; several aircraft disappeared from my stars tdw or appeared in places they were not. One aircraft in particular; PA-28R; I visually observed on the right downwind to runway 7R (about a 250 heading). For at least one or two radar returns; PA-28R's target appeared to be heading 160 at 170 KTS about a half mile south of where he actually was. Other aircraft simply vanished from the tdw all together as if they weren't there. I notified the supervisor who informed me they had changed radar channels earlier in the day with no improvement. Although visually identifying aircraft out the window is the primary method for running the traffic pattern; inconsistencies on the tdw cause a lot of confusion. Also; a half-mile jump in a target's position could mean the difference between having separation and not. Fix our equipment whether the problem lies with fusion; our ASR-9; or stars in general. This kind of presentation is unacceptable and dangerous.

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Original NASA ASRS Text

Title: DAB Controller voiced concern regarding the STARS TDW equipment indicating targets are not displayed accurately; unsure if the problem is caused by FUSION; the ASR-8 or some other equipment anomaly.

Narrative: While working LC2 I had up to 8 aircraft in the VFR traffic pattern. During that time; several aircraft disappeared from my STARS TDW or appeared in places they were not. One aircraft in particular; PA-28R; I visually observed on the right downwind to Runway 7R (about a 250 heading). For at least one or two RADAR returns; PA-28R's target appeared to be heading 160 at 170 KTS about a half mile South of where he actually was. Other aircraft simply vanished from the TDW all together as if they weren't there. I notified the Supervisor who informed me they had changed RADAR channels earlier in the day with no improvement. Although visually identifying aircraft out the window is the primary method for running the traffic pattern; inconsistencies on the TDW cause a lot of confusion. Also; a half-mile jump in a target's position could mean the difference between having separation and not. Fix our equipment whether the problem lies with FUSION; our ASR-9; or STARS in general. This kind of presentation is UNACCEPTABLE AND DANGEROUS.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.