OPERATION HARDIACK I - DATE: TIME: PPG Time 30 May 1958 1415 Tobacco Sponsor: GMT 30 May 1958 0215 SITE: LASL PPG - Eniwetok - 3,000 ft NW of Janet 179 39' 48" N 162° 13' 48" Site elevation: &£ Sea level TYPE OF BURST AND PLACEMENT: CLOUD TOP HEIGHT: 18,000 ft MSL CLOUD BOTTOM (ISIGHT: WM REMARKS: Only individual island dose rates are available. These were abtained from helicopter surveys made by the Radiological Safety organization at H+l. 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-1-2 decay approximation was used to extrapolate the Hth hour dose rate readings to H+l hour. 226 7 Surface burst from barge on water