WER) cua) Project 6.3 ~ Effects of Atomic Explosions on the Ionosphere - M. Hawn ORJECTIVE The objective of Project 6.3 was to obtain data on the effects of high yield nuclear 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. LiSTRULENTATION The system comprises: Two jonospkere recorders, type C-2, operating on pulse transmission, 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 Islend. Detailed Description: Ionosphere recorder site (Rongeriz Atoll) site (Kusaie) AN/CPQ-7, type C-2 ionosphere recorder with a power output of 10 KW peak pulse alternately transmitting and receiving automatically over the range of frequencies from 1 to 25 megacycles, This eguipment measures and records at vertical incidence the virtual height and critical frequencies of ionized regions of the upper atmosphere. A 600 ohm multiple wire antenna designed and erected, so that the direction of maximm intensity of radiation will be at the desired vertical angle over all of the operating frequency range from 1 to 23 megacycles. DOE - 51 - as C