Intelligence Review of “Ghost Rocket” Incidents, 1947

What the war.gov catalog says

This document is a U.S. Department of War General Staff intelligence review assessing incidents involving unidentified “Ghost Rockets” reported over Sweden and other Scandinavian countries beginning in May 1946. The review includes an analysis of observational reports, statements from the Swedish government, and reporting from the U.S. military attaché in Stockholm. The review highlights the inconclusive nature of the contemporary evidence available to substantiate reports from civilian and military observers. The review also documents a change in the public stance of the Swedish Defense Staff, which privately attributed the objects to Soviet V-1 missile tests launched from Peenemünde. Peenemünde is a then-occupied municipality in northeastern Germany that had been associated with the development of the V-1 and V-2 rocket program during World War II. The Swedish assessment publicly shifted from an unknown technological origin to one of a “celestial origin.” The review suggests that this shift was a deliberate effort to avoid diplomatic conflict with the Soviet Union. The report’s final assessment concludes that while most reported incidents were likely misidentified natural phenomena, the “best evidence” suggested a small number of “real incidents” involving low-flying V-1 type missiles, likely attributable to Soviet tests of captured German technology.