Ground and Airborne Radar Observations of Unidentified Targets

This intelligence report details an incident on March 20, 1955, involving radar observations of unidentified targets over central Honshu, Japan. At approximately 1613 local time, the Tokyo Radar Traffic Control Center at Johnson Air Base detected sixteen targets in six formations. The targets appeared to move in a southeasterly direction. An F-86D aircraft, piloted by 1st Lt. C. D. Merrick, was scrambled from Yokota Air Base to intercept. During the pursuit, the pilot reported radar contact with two targets, but was unable to achieve visual confirmation. The pilot noted that the targets exhibited erratic motion and that his radar performance was generally good, though he experienced difficulty maintaining a lock. The report includes detailed accounts from the radar controllers and the pilot, noting that the targets eventually became stationary. The official evaluation, prepared by Captain Douglas J. Davis of the Air Technical Intelligence Center, concludes that the targets were likely the result of a temperature inversion, which created false echoes from ground targets. The report highlights that this was the first instance of such a prolonged airborne pursuit of unidentified targets and expresses surprise at the radar's behavior. The investigators noted that while the spurious response theory is supported by the fact that only two of the sixteen targets were observed on the aircraft's AI radar, there was insufficient data for a definitive evaluation. The report includes several enclosures, such as weather charts and radar overlays, to support the analysis of the atmospheric conditions at the time of the encounter.