OPERATION HARDIACK I - TATE: TIME: —— PPG Time 29 June 1958 0730 Oak GMT Sponsor: 28 June 1958 1930 LASL SITE: PPG - Eniwetok - 3 mi SW of Alice TOTALYIELD: 8,9 Mt 11° 36' 28" 162° 06' 28" Site elevation: FIREBALL DATA: Time to lst minimum: Time to 2nd maximum: Radius at 2nd maximum: CRATER DATA: Diameter: Depth: Water depth: NM 2.98 sec HEIGHT OF BURST: NM N § Sea level 13 ft 6.5 ft TYPE OF BURST AND FLACEMENT: Surface burst from varge on 4,400 ft 183 ft water CLOUD TOP HEIGHT: 78,000 ft MSL CLOUD BOTTOM HEIGHT: iM REMARKS: Only individual island dose rates are available. These were obtained from Radiological Safety organization helicopter surveys at H+4 hours. The helicopter survey technique called for the pilot either to land the aircraft at a desired spot, sco that a ground reading could be obtained or to make a slow pass over the desired spot at an elevation of 25 feet. Readings taken at 25 feet were multiplied by a factor of 2 in order to obtain a reasonable approximation of the true ground reading. The basic instrument used in the aerial surveys was the AN/PDR-39 survey meter modified to read up to 500 r/hr. The t-l:? decay approximation was used to extrapolate the H+4 hour dose-rate readings to H+l hour. 266