Seeger @ a. Teller Time interval. bd. Electromgnetic time interval. e. Fireball yield. dad. ENS timing and primry alpha by telemetering. e, Such reaction history as feasible by the optical method being used and to be proved in Operation Plumbbob. Considerable effort and thought have already gone into the planning for remte diagnostics and the same remote experiments will be performed from land based equipment on Tare in diagnosing shots in the northern test areas at Bikini. Remote diagnostics obtained at sea are not without precedent since time interval and fireball yield were obtained from the command ship on the Mike Shot, Operation Ivy. The five shots would be placed on barges moored in the lagoon, probably toward the northern end, The first of these shots wovld be placed near the leeward reef so as to broach an opening approximetely equivalent to the crater diameter, Each succeeding shot barge would be moored on the edge of the ‘previously formed crater in order to open a navigable deep water channel into the lagoon and to form, with the lergest shot, a turning basin at its end. This stepwise strategic placement and encroachment into the lagoon would result in a man-made deep water anchorage for possible use in the future. The sequence timer and radio firing racks would be placed aboard the shot barge. Such a method is very feasible and the reliability of the system has been proven in past operations. The firm of Edgerton, Germeshausen, and Grier, Ine., who normally provide the firing equipment, have considered this system for Hardtack and are able and willing to provide» install, and operate the necessary equipment. Weather and Geography One of the greatest gains to be netted in this use of Taongi Atoll is the opportunity of taking advantage of its isolated and unique position with respect to populated areas. The nearest populated area west of Taongi is Guan, some 1,300 miles distant. To the east, no populated area exists for at least. 1,500 miles. To the north, the nearest population is on Wake bearing NNW 304 miles distant. miles S by E of Taongi. The closest population of any is Utirik Atoll, 215 One of the reasons for advocating minimal construct- ion ashore at Taongi is to assure no need for reoccupation of the islands and since taking full advantage of being able to fire with the stable Taongi vind pattern is certain to produce heavy fallout on them. Typical hodographs of shot time observed winds at Eniwetok and Bikini, with their usual inverted S.shape to the north, are indicative of the desirability for southerly components in the levels from 20,000 feet to the tropopause. The stable winds above ani below this middle layer very seldom change in direction, being mostly easterly in both the upper and lower layers.