OPERATION HARDTACK I ~-

DATE:
TIME:

PPG Time

27 July 1958
©6830

Pine
GMT

Sponsor:

206 July 19.8
2030

SITE:

UCRL

PPG - Eniwetok - SW of

Janet, 8,000 ft to

nearest edre or island
"
a
11° 39!
ce
N

162° 13'

11"

Site elevition:

HEIGHT OF BURST:

CLOUD HEIGHT:

&E

Sea

level

€&.0 ft

TYPE OF BURGT AND FLACEMENT:
Surfuce burst Yrom barge
on water

Not available

REMARKS:
Only individual island dose rates are available.
These were obtained
from the Radiological Safety orginization helicopter surveys 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 fret.
Readings taken at 25 reet were
multiplied by a factor of 2 in order to obtain a reasonable
approximation or the true vround reading.
The basic instrument
used in the aerial surveys was the AN/TDR-39 survey meter modified

to read up to 500 r/hr.

The t-+** decay approximation was used

to extrapolate the Ht hour dose-rate readings to H4l hour.

303

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