i: A problem as yet unsolved is the determination of the location of the ships during the survey. A list is being made of markers of all types which are expected to survive the shots. These, however, will not cover all of the area, especially the traverses out to sea. Inquiry will be made of the possibility of determining location by radar , per~ haps with the air search radar on Eniwetok if its range is sufficient for a surface vessel. VIII. OPERATIONAL PLANNING A. General Upon completion of Operation Tumbler~Snapper in Nevada full attention has been focused on the forthcoming overseas tests, Operations Ivy and Castle. An operational concept for Ivy has been formulated by the scientific task group and disseminated for further operational planning by other participating agencies. Some planning for Operation Castle, tentatively scheduled for September-October 1953, has been accomplished. This has been of a limited nature due to the immediacy of Operation Ivy. B. Operational Concept - Ivy (4) No changes have occurred in the basic planning as to number of shots, dates, type of shots,,and expected yielis, Two shots will be conducted at Eniwetok Atoll in the Fall (4) Concept of TG 132.1 Forward Area Operations, J - 11689, _— dated 19 May 1952 (since revised), .