OPERATION HARDTACK I TATE:
TIME:
PPG Time
27 May 1958
O600
Magnolia
GMT
26 May 1958
1800
Sponsor:
SITE:
LASL
PPG -~ Eniwetok - SW of
Yvonne, 3,000 ft from
the nearest edge of the
island
11° 321
162° 21'
3h"
14"
Site elevation:
HEIGHT OF BURST:
N
&§E
Sea level
13.88
ft
TYPE OF BURST AND PLACEMENT:
Surface burst from barge cn
water
CLOUD TOP HEIGHT: 44,00C ft MSL
CLOUD BOTICM HEIGHT: 15,0CC ft”
REMARKS:
Only individual island dose rates are available.
These were obtained
from helicopter surveys made by the Radiological Safety organization at
H+4 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 e 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-1-4
decay approximation was used to extrapolate the H+4 hour dose-rate
readings to H+l hour.
222