DELETED — Project 6.3 = Effects of Atomic Explosion on the Ionosphere - M, A. Hawn Objectives The objective of Project 6.3 is to obtain data on the effects ofDELETED DELETEDMeclear explosions on the Ionosphere. Principally, to investigate the area of absorption, probably due to the high altitude radioactive particles, and to study the effect of orientation relative to the earth's magnetic field on F2 layer effects. Instrumentation The system comprises: « Two Ionosphere recorders, type C-2, operating on pulse transmiss— ion, installed in 6 ton trailer vans, one located at Rongerik Atoll and one located at Kusaie in the Caroline Islands, One Ionosphere recorder, type C=3, operating on pulse transmission, installed in a C~97 plane based at Eniwetok Island. Preliminary Results All stations operated successfully during this test. C~97 Airborne Station: The same effects as experienced on the DELETED (CHEROKEE) and the-ELETEzunI) were present but to a much smaller extent. Complete absorption was experienced when the aircraft was inside the absorb-= ed region. However this region of absorption was not as large as for the DELETED Also the disturbance to the Ionosphere echo shape was relatively minor in comparison. Abnormal echoes lasted less than forty minutes. Kusaie: ing the COPIED/DOE LANL RC The same effect occurred in the F region as was observed dur- DELETED ests but of lesser duration and magnitude. a 3