wm SLyrlopient Inaboratories for analysis, The aircraft was quipped with .° ‘lo sitincter,FOR 718, with an accuracy of £ 25 feet beitween 200 and 60,000 feet \titude over smooth terrain, t the tine Readings were taken fron the radto altir2ter the plane cane into the flight pattern for r-king the aerial photographs and any changes were noted, Passes were nade at altitudes of 1,740, 1,700, and 1,750 feet. Radiation has prevented making postshot depth survey; but this will be Renge poles will be placed et the end of accomplished as soon as possible, the pre-surveyed Radii 2, 3, end & (Fig. 1,@-1), and transits will be sect up at the end of Radii 1, 5, and 6, An LCM or DUKW will enter the crater end lead line soundings, five per radii, will be made and the point of the ggynding will be triarnguwiated by the transits, 7 SULTS .3 C2che:d that a lead line sourcing +ovld Us i zde Tloa a Lalies cert “oprexdmately ground zero, A Rad-Safe survey flown at an altitude of 10 fect ->3 ~3de at D ¢ 11 (1200 hrs 16 May 56) giving the results as <-hen in Pie, On D £ 12 (17 May 56), a sounding was sede from a helicopter ulich a 1,2-2, hovered over ground zero at appraxinately 25 feet. The sounding made, cori ected to the catun plane (6 inches below san low - stor spitting), gave the copth e.ster to be 45.4 feet. of th The survey took approximately 15 minutes for 5: “ticn- tng the helicopter and raking the sounding; persons exposed received zero -siistion. The postshot aerial photographs were studied; the diameter from rim to rim of the lip was estimated to be 430 feet, CONCLUSIONS is No conclusions can be drawn until the findings of the film analysis end the lead line soundings have been made. cor ied | poe wi ®G se = 2) ~ FT]