the chamber and normal to the axis of the chamber. angle was relatively flat as shown in Figure 2.6. The integrated response over the 471 solid From this curve it can be seen that the re- sponse of the chamber was independent of energy within + 10 percent from 90 to 2,000 kev. The radiation transducers for the rocket flights showed a range of sensitivities of 0.17 to 0.39 pulse/sec/r/hr when calibrated with a 4-curie point source of Co®, As noted above, the sensitivity was reduced by 15 percent when the transducers were operated inside the rocket ogive in a uniformly distributed radioactive field. 2.2.3 Launching Site, A launching revetment was constructed on Site How (10 to 18 miles from the shot points). The revetment consisted of two concrete launching pads, each 100 feet by 12 feet; an embankment to protect the launchers from possible water waves; and an instrument shelter. Firing of the rockets was controlled by a sequence timer located in the instrument shelter. The timer was armed by a minus 1-second signal provided by an Edgerton, Germeshausen and TABLE 2.1 RANGE AND BEARINGS OF SHOT POINTS FROM RECEIVING STATIONS AND LAUNCHING REVETMENT Shot Cherokee * Zuni Navajo Tewa Site How Launching Revetment Range Bearing 92,3u0f 285% 76 ,800T 2325 55,600 Tf 2835 73,000 T 283¢ Site Nan Receiving Station Range Bearing 116,000 ft 3025 70,800T 261% 8i,000T 308 97,100Tt 304t APD 101 Receiving Station Range Bearing 195,000 ¢ 330 f 165,000 + 280t 160,000 T 315 200,000 t 310f * Planned Ground Zero. t Range, feet. } Bearing, degrees. Grier (EG&G) timing relay. Two blue boxes were arranged so that the timer wouldalso start if one or both of the boxes were triggered by the bomb light. The timer started the local power generators after the blast wave had passed, (The local power generators were left running when the shelter was secured for Shot Cherokee and the shock wave stopped them; therefore, the generators were started by the sequence timerafter passage of the shock wave for subsequent shots.) turned on the long-wave transmitter, started the rocket telemeters, uncaged the rockets, ignited the rocket flares, and fired the rockets. Power for all but the long-wave transmitter was supplied by batteries. The long-wave transmitter, a BC-610 AM transmitter operated at 2.545 Mc, was located at the launching revetment and relayed the launching times of the rockets to telemetering receiving stations. 2.2.4 Receiving Stations. Duplicate receiving stations were set up at Site Nan and aboard the USS Knudson (APD-101). Figure 2.7 shows the position of the receiving stations. Table 2.1 gives the range and bearing of the various ground zero locations from the launching revetment at Site How, the shipboard receiving station, and the Site Nan receiving station. The two receiving stations were similar except that the one at Site Nan was unmannedat shot time and was equipped with automatic timing equipment to operate the recording devices. The basic equipment of the stations consisted of six Raymond Rosen 842-C FM telemetering receiv~ers, a R-390/Urr AM receiver tuned to 2.545 Mc, and an Ampex Model § 3530 seven-channel tape recorder. Telemetering frequencies of 223, 224, 225, 226, 227, 228, and 239 Mc were assigned, giving six channels and one spare. The six signais from the rocket telemeters were detected and recorded on six of the channels. The launch signals from the BC-610 transmitter at the launching site were recorded on the seventh channel. In addition to the basic information 18