OPERATION HARDTACK I -
DATE:
TIME:
PPG Time
Poplar
GMT
12 July 1958
1530
Sponsor:
12 July 1958
0330
SITE:
UCRL
PPG - Bikini - SW of
Charlie, 7,500 ft from
the nearest edge of island
1i° hit
165° 15'
17"
5o"
Site elevation:
HEIGHT OF BURST:
N
&§E
Sea level
11.66 ft
TYPE OF BURST AND PLACEMENT:
CLOUD TOP HEIGHT:
Surface burst from varge on
water over reef
> 61,000 ft MSL
CLOUD BOTTOM HEIGHT:
42,000 ft MSL
REMARKS:
Only individual island dose rates are available.
These were obtained
from the Radiological Safety organization helicopter surveys 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 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-!*? decay approximation was used to extrapolate
the H+ hour dose rate readings to H+] hour.
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