OPERATION HARDIACK I -
DATE:
TIME:
PPG Time
31 May 1958
1500
Sycamore
Gur
Sponsor:
31 May 1955
0300
SITE:
UCRL
PPG ~ Bikini - SW of
Charlie 4,000 ft from
the nearest edge of the
island
11° 4i't
165° 16'
27"
25"
N
£E
HEIGHT OF BURST:
11.64 ft
TYPE OF BURST AND PLACEMENT:
Surface burst from barge on
water
CLOUD TOP HEIGHT: 46,000 ft MSL
CLOUD BOTTOM HEIGHT: NM
REMARKS:
Only individual island dose rates are available.
These were obtained
from helicopter surveys made by the Radiological Safety organization
at H+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-1+® decay approximation was used to extrapolate the Ht+4 hour
dose rate readings to H+l hour.
230
——
Site elevation: Sea level