TIME: PPG Time 22 May 1953 0920 GMT 21 May 1958 Sponsor: 2120 SITE: UCRL PPG - Bikini - West end Tare 119° 29' 165° 22' 6" 15" Site elevation: HEIGHT OF BURST: N &E Sea level 12.11 ft TYPE OF BURST AND PLACEMENT: Surface burst from barge on water CLOUD TOP HEIGHT: 20,000 ft MSL CLOUD BOTTOM HEIGHT: IM REMARKS: Only individual island dose rates are available. These were obtained from helicopter surveys made by the Radiological Safety organization at H+ hours. The helicopter survey technique called for the pilot either to land the aircraft at the desired spot, so 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-2°2 decay approximation was used to correct the H+4 hour doserate readings to H+l hour. 214 ore DATE: Nutmeg ——w OPERATION HARDTACK I -