Arcata: Radar technician documents unidentified targets

Radar Detection Kenneth W. Ehlers, a radar technician at the Landing Aids Experiment Station in Arcata, California, accumulated data on unidentified radar targets he termed "gizmos." These objects appeared on radar screens but remained invisible to the naked eye.

Flight Characteristics The targets consistently traveled at approximately 30 mph along a northwest-to-southeast trajectory parallel to the coast. They exhibited unusual behavior: occasionally halting completely, splitting into multiple objects, or merging back together. The radar signatures indicated small solid targets.

Investigation and Analysis Kenneth Arnold visited the facility in spring 1948 to interview Ehlers about these phenomena. Ehlers had been reporting his findings to Navy meteorologist Florence Van Straten and Luis Walter Alvarez, inventor of the Ground Control Approach System radar. While some attributed the targets to insects, Ehlers remained skeptical. He later theorized they might be plasma formations at atmospheric inversion layers, though this hypothesis failed to account for their controlled movements.