interference by natural clouds. Four of these were on Shot 3, which was fired under such bad weather conditions that no useful cloud photographs of any sort were taken from the ground or alr. The data obtained were more complete and accurate than any from previous operations (see Table 9.1; Ivy data is included for comparison). Good measurements of cloud height and diameter over a 10-minute interval were compiled by EG&G for the five shots photoTABLE 9.1 CLOUD PARAMETERS No data were obtained for Castile Shot 38. ss Maximum Height BH+i min Top at Diameter at Diameter at H+ min 8 +10 min 1of ft 10 ft 10? ft io tt Castle 1 2 4 5 8 114 110 94 110 72 47 44 35 44 25 38 33 26 3 19 370 316 125 270 147 Ivy Mike Ivy King 98 718 33 28 39 wn 200 90 graphed. It was found possible to apply suitable corrections for the effects of earth curvature and atmospheric refraction, for the slight tilt of the camera platform, and for the altitude of the aircraft. The resulting data agreed quite well from one aircraft to another, and it was possible to assign smaller uncertainty to the results than had been anticipated. Unfortunately, it was not possible to evaluate the few data taken later than 10 minutes after aetonation. 103