ZSE controller voiced concern regarding false type targets observed when operating on the eram syste...

Narrative:

A B737 and a B757 had merged targets approximately 15 NM south of crater lake. Conflict alert went off with the B737 and a target at FL415. Both aircraft were asked to recycle their transponders and I made sure they were on their appropriate code. There was an unrelated beacon marker over the targets. After about 20 NM the conflicting code stopped tracking and disappeared. This is the third time I have seen this type of problem with eram tracking aircraft that are not there!! There was a controller in charge present and we decided not to turn the aircraft since this is a known issue; but if it had been on a low altitude sector I would have been forced to turn both aircraft for a radar system that simply doesn't work right. Eram doesn't track the aircraft correctly; they will say that this is due to lmt radar and it just isn't true. No controller in my specialty has seen this type of ghost targeting with host.

Original NASA ASRS Text

Title: ZSE Controller voiced concern regarding false type targets observed when operating on the ERAM system; indicating that this type of occurrence was happening more and more often.

Narrative: A B737 and a B757 had merged targets approximately 15 NM south of Crater Lake. Conflict Alert went off with the B737 and a target at FL415. Both aircraft were asked to recycle their transponders and I made sure they were on their appropriate code. There was an unrelated beacon marker over the targets. After about 20 NM the conflicting code stopped tracking and disappeared. This is the THIRD time I have seen this type of problem with ERAM tracking aircraft that ARE NOT THERE!! There was a Controller in Charge present and we decided not to turn the aircraft since this is a known issue; but if it had been on a low altitude sector I would have been forced to turn both aircraft for a RADAR system that simply doesn't work right. ERAM doesn't track the aircraft correctly; they will say that this is due to LMT RADAR and it just isn't true. No Controller in my specialty has seen this type of ghost targeting with HOST.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	945452
Time
Date	201104
Local Time Of Day	1201-1800
Place
Locale Reference	ZSE.ARTCC
State Reference	WA
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Aircraft 2
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Person 1
Function	Enroute
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types

ZSE controller voiced concern regarding false type targets observed when operating on the eram system; indicating that this type of occurrence was happening more and more often.