cloud sempling aircraft operating during the same period, and was die~
seminated for the purpose of assisting these aircraft in finding the best
sampling srea.
In general, tha construction of tn2 air RDEX consisted
of selecting an altitude at the bottom of the vile under consideration,
considering this altitude as a surface, and constructing a hodograph oy
this "quasi-surface" using appropriate winis above tne surface.
Cone
taminated areas were then defined by the use of diffusion factors applied
time-wise to the resultant winds obtained, and modified te account for
deviation fram = point source origin of fall-out.
The air ROEX wes also
issued for a valid period of H to H plus 6 hours, fevised as neceseary,
and disseminated to all test personnel with particular attentiat to its
availability and use by the (ir Operations Canter,
(0) New Teghniquee:
J. new techrique te define the
close-in fali-cut was developed to explain the shot atoll phencaaitt, and
was wed partisularly to evaluate tho foresast effects oS MECRAR on the
DHIWETOK samp site,
(Ses Incl 3 of Tab 5D).
‘This nethad, in general,
employs « methematical approach to the initial close-in distribution of
fall-cut,
(3) Pall-cut Plots:
(a) The primary fall-out plot technique planned and
initially used om C)STLE involved « jciut amilysis of the surface RDEE
and the 72-hour air particle trajestory fcresast to define the ares of the
first twelve-hour period of fall-out, end to formilate some opinion as to
the crplentation and extent of the area inwlved cubsequent to the first
twelve hours. Por BR:VO an attexpt ws made to employ the method of
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