OPERATION GREENHOUSE DATE: TIME: —_—— PPG time 8 Apr 1951 0634 Dog GMT 7 Apr 1951 Sponsor: 1834 SITE: LASL PPG - Eniwetok - Yvonne 11° 33' 21" N 162° 21' 16" &£E Site elevation: HEIGHT OF BURST: Sea level 300 ft TYPE Or BURST AND PLACEMENT: Tower burst over coral soil CLOUD TOP HEIGHT: CLOUD BOTTOM HEIGHT: 56,000 ft MSL 323,000 ft MSL REMARKS: The dose-rate readings were corrected to H+l hour by applying the t-1-? law to measurements made by the Radiological Safety organi- zation. Measurements on Yvonne were made at H+83 hours. Many of the measurements were obtained from a helicopter flying at an altitude of 10 to 20 feet above the ground. These readings may therefore be low by as much as 20 to 50 percent. The wind shear at about 20.000 feet acccunts for the higher dose rates on the southeastern part of the atoll, as compared to the southern end of the shot island. 27