* OTaL?ONENN RR a A oe sites should be located to the east, the sovth, or the north of the Might source, so the light collectors do tot view the eastern eky as background. in the Pacific, poseible g>ounc tocations are }imited to islands on which experimente can be supperted. Noeded weather uata for some of the Pacific islands are meager. After consideration, the islands selected were Jr‘ sston Island (3,100 km) and Kwajalein (620 km). Arrangements were also made for shock mountiig light detection equipment in a C-47 Air Force plane and Nying tt above Kwajalein on 2 course that would froperly orient the equipment to receive the emitted light at detonation time. Tee stations were operated by Air Force oficer and enlisted personne! who had participated in Project 7.10 «napper, with additionu, to provide a total of aix men for the three stations. Before being sent into the field, all people participating became familiar with the operation of the equipment at an AFOAT-I1 fte!d office. Radios were used to monitor the AFSAL timing signals of the Task Force alert and timing system. Accurate timing signala were necessary because the recording period was short, varying between about 14 seconds and 20 seconds, depending on the freshness of the camera-onerating battery. A supplementary radio commmuications Ilak was se’ up between Program 7 Headquarters on F.wafjaiein and the station on Johnston Islard. Two recording channels were used at the Johnston and the Kwajalein groun ‘ stations, one a lens pickup and the other a2 reflector pickup. The aircraft station used a lens pickup. All pickups used a red-sensitive (RCA 925) photocell except the lens pickup at Johnston which was blue-sensitive (RCA 929). Iron posta to hold the pickups were cemented in the earth at both ground stations. The aircraft pickup pointed out an open window and was shock mounted to reduce vibration ag much as rosaithle. As reported by Cupt Carrol] L. Hasseltine: “AFSAL time signals giving the time until detonations were received from the forward area during the entire operation. The sched- uled detonation times were compared with the times given by the AFSAL signals. (Wam- era starting times] were obtained from stop watches checked against WWVH time signals in Hawail which was contacted periodically. Cameras at Johnston und the ground camera at Kwajalein were started in operation for the Mike shot with the AFSAL five-second- until-detonation signal which occurred at approximately 1914: 59 Zulu on 31 October 1952. The camera installed with the ‘bhangmeter’ equipment in the aircraft was started by using a stop watch for timing at 1914:552Z. Photographs of the horizon in the target direction were taken as scon as practical after the shot. All 16-mm film was forwarded to Headquarters, Program 7 after the shot. The aircraft carrying the ‘bhangmeter’ equipment was at approximately 9 degrees 15 minutes North, 167 degrees 04 minutes East at 16,000 feet flying a 201 degree magnetic course when the camera was started. For the King shot the camera at Kwajalein was started with the AFSAL five-second- until-detonation time signal which was 2300: 04 Z on 15 November 1952. The aerial camera was started approximately 55 seconds after hearing a ‘bombs away’ broadcast on the radio. The airplane was located over the field at 12,000 feet. The Johnston cameras were started sometime between their scheduled five-second starting time, 2329: 58 Z, nod the AFSAL five-second signal which occurred at 2330: 04 Z 15 November 1952. Target horizons were photographed as soon as possible after the shots and the film forwarded to Mr. Colsor. of Edgerton, Germeshausen and Grier.” INSTRUMENTATION The system used for long rarge light detection is described in the final report of 7.1b Snapper (Reference 3). Briefly, a single channel consists of the following main components: (1) a light collector: this was cither a tube with a condensing lens and photocell or Rt Btls: tem li v