MD-82
Flight Crew Air Transport Pilot (ATP)
Workload; Distraction; Confusion
Aircraft Equipment Problem Less Severe; Deviation - Altitude Overshoot; Deviation - Altitude Excursion From Assigned Altitude
Air Traffic Control Issued Advisory / Alert; Flight Crew Took Evasive Action; Flight Crew Returned To Clearance
Aircraft
At FL340; we received a TCAS Resolution Advisory to climb. The red target displayed was at our altitude and appeared to be on a collision course. We followed the RA and climbed to FL350 and advised ATC. ATC advised us that they had no traffic in the area but that we were near military airspace. After visually assuring that there was no other aircraft nearby; we descended to our assigned altitude and selected TA on the transponder. The false target mirrored our position for a while; then disappeared.I suspect that there was nothing wrong with our equipment but that we encountered military interference/jamming.Since I believe the problem was external; I hope the FAA can coordinate with the military to avoid a recurrence.  However; the TCAS was written up in the aircraft's maintenance log.
[Report narrative contained no additional information].
A MD-80 climbed to FL350 after the TCAS issued a RA CLIMB at FL340 from a target at their altitude which mirrored the aircraft. ATC reported no traffic. A TCAS Null Bus Fault own ship escape was a possible cause.