RPT OF A DEPARTING T34'S DATA TAG JUMPING TO AND MERGING WITH A MIL FFJ'S TAG. AND RPT OF A LNDG ACFT'S TAG APPEARING NW OF THE ARPT WITH MODE C READOUT WHEN THE ACFT IS ACTUALLY ON THE RWY.

Narrative

I WAS WORKING DEP; RADAR AT GULFPORT APCH GULFPORT; MS. A T34 DEPARTED RWY 14 HDG 270 DEGS. AT THE SAME TIME A MIL ACFT AT THE SAME ALT WAS INBOUND ON THE ILS FOR RWY 14; 6 MI NW. THE BEACON CODE AND MODE C ALT JUMPED 4 MI NW RIGHT IN FRONT OF THE FFJ. BUT THE ACFT WAS REALLY 7 MI W OF GPT; PLUS THE CODE OF T34 WAS MOVING NW AND MERGED WITH FFJ TAG. WE HAVE HAD MANY PROBS WITH BEACON TAGS. WHEN ACFT LNDG AND THEIR TAGS JUMPING 4-6 MI USUALLY 4 SW AND THEIR MODE C ALT OF 200-600 FT WHILE THE ACFT IS REALLY ON THE RWY. THE COLLISION AVOIDANCE ALARM WILL SOUND WHEN ANOTHER ACFT TAG IS IN THE AREA AT A CLOSE ALT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THE PROB IS GETTING WORSE AND THAT THE ARR TAB LIST HAS STARTED JUMPING AROUND GENERALLY TOWARD THE CTR OF THE DISPLAY. RPTR ALSO STATED THAT THEY ARE GETTING NUMEROUS LOW ALT ALERTS. IN ANSWER TO ANALYST QUESTION; RPTR STATED THEY WERE AN ARTS 2A FACILITY AND THEY RECENTLY HAD A NATIONAL PATCH INSTALLED. RPTR ALLEGES THE SUPVRS ARE NOT ALWAYS LOGGING THE TAG/TAB LIST PROB EXCEPT WHEN THE SYS IS UNUSABLE. RPTR INDICATED THE FACILITY MGMNT IS SUPPORTIVE TO HAVE THE PROB FIXED AND BELIEVES IT HAS BEEN ELEVATED TO THE HUB FACILITY.