= Co AL Air navigational adsconsisted principally of a system of low frequency homers, supplemented by a GCA and TACAN at Eniwetok, The low frequency homers were located at Bikini, Enivetok, Kapingamarangi, Uterik, and Kusaie, | The GCA at Eniwetok was an AN/UPN~11B incorporating modern radar developments such as moving target indicator and circular polarization for improved weather penetration. This facility provided valuable assistance particularly when working with the AOC in recovering jet effects aircraft after a test. The TACAN set located on Sand Island operated without difficulty. This aid could only be utilized by the B~57B samplers and the Navy effects aircraft. « The Air Operations Center (AOC) at Eniwetok was responsible to the 4 Task Group Commander for the safe positioning of all aircraft in the test array. To accomplish this mission, the AN/USQ-12 manufactured by the Hazeltine Corporation was employed. This facility was able to see and present the relative positions of aircraft at ell times during a test operation. Basic components are eight (8) UPA/35 sccpes, 12 channels of UHF communications and associated hot line telephone systems, Seven air controllers may operate the equipment simltaneously. (The UHF transmitters and receivers are located in separate vans and operated through telephone tie lines). The AN/USQ-12 was not considered adequate for some of the precise positioning necessary for the effects program. Primary positioning of effects aircraft was in most instances conducted by the MSQ-1 or M-33 radars monitored by the AOC, Each effects aircraft required a clear UHF channel to its assigned positioning radar thereby seriously reducing the number of channels available for AOC operation.