.ner map receivers (telephoto) were used in the Weather Center. TWOfacsixr. They received and reproduced two surface weather charts and four upper-air charts daily from the Fleet Weather Centrals at Guam and Pearl Harbor. At the outset of the Operation there were but two weather stations in the test area, Kwajalein and Wake Island. Insufficiently equipped and manned to record and transmit the data required for Operation Sandstone, these stations were augmented by the Task Force to make them serviceable. Additional stations at Eniwetok, Rongerik and Majuro were established. These stations formed the basic weather network. Kwajalein and Eniwetok provided a forecast and briefing service for local Commanders and aircraft of the Task Force. Augmenting the weather service of the island stations, eight B-29 aircraft especially equipped for weather reconnaissance were furnished by the 51lth Weather Reconnaissance Squadron at Guam. Training presented no problem here as the personnel were well trained and the need for preparation was minor. Data from these aircraft was received by the Base Weather Office of Task Group 7.4 at Kwajalein and was then relayed by radioteletype to Eniwetok and thence on to the Task Force Weather Center on the Command Ship. Reconnaissance tracks for the weather aircraft were planned specifically for Operation Sandstone. A warning network for the immediate vicinity of Eniwet.ok was established to provide forecasts of the time of be~nning and ending of showers aS well as their speed and direction. Sources of data for this warning service were weather reconnaissance aircraft reports, radar reports from these aricraft and the radar reports from the Task Force ships. During the pre-test period the Meteorological Section made daily analyses and forecasts and during the early stages of this period briefings were presented to the Commander, Join Task Force Seven, for familiarization, looking toward the time when briefings would be “for record.” Documentary photography, both technical and non-technical, constituted a part of the pre-test operation as it did during the later test periods. Seven photographic teams operated throughout the test area, taking both still and motion pictures. A small film processing laboratory was operated aboard the USS Ch.mtiss. The purpose of this laboratory was to give rapid service in printing technical photographs urgently needed in the Operation. Basic photographic requirements for operation Sandstone called for four types of operating units in the test area: an aerial photographic unit; an organization to insta]l cameras and allied timing equipment in the photographic’ tower plus the technical and documentary teams and the processing laboratory already mentioned.25 Practice runs for familiarization and Orierlt.ation on the target were made by the aerial photographic unit during the pretest days. Installation of photographic equipment in the photographic towers pr~eeded in parallel as conditions permitted. In order to assist the aerial photographers in aiming their cameras at the target position, a horseshoeshaped string of red lights was placed around the firing towers on the test-firing islands. The arrival of the Headquarters of Joint Task Force Seven at Eniwetok on 16 March marked the assembly of the Task Force as a unit for the first time. Despite the fact that flsSW.XVIII. Annex I, contains the detailed phota graphic report. 117