WMOD00372

• Project Name: High Plains Cooperative Program
• Title: The Design of HIPLEX-1
• Date: 4/1/1979
• Weather Modification - Doc Type: Report

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where R(s) is the rainfall rate measured at a distance (s) along the
aircraft flight path and where the integral extends over the ith
pass.

2. Weighted average positions of the rainfall (5i) and standard
deviations (oi2) from these positions are calculated for each pass
accord i ng to the formul as

!;. = L J s R( s) ds
1 T.
1

2
Di =

I
T.
1

J (5 -

2
Si) R( s) ds

3. Between passes i and i + 1, the area integral of the rainfall
rate is estimated as

AI i = ~ 2lf TiT i +( i (j i

This would be an exact result if the rainfall were distributed in
a Gaussian distribution of the form

R(x.y) = Ro exp (- /2 -~)
20" 2(1
X Y

For a uniform distribution of rainfall within a circle or an ellipse,
the same formula would hold with a constant of I3(T/2) = 2.72 instead
of ..[2:; = 2.51; sl ight1y different constants would apply to other
geometries.

4. AER is evaluated from

~

N - I
AEIR~ == L:

1 = I

A . (t. - t. )
1 1 + I 1

where ti is the time of the ith pass and N is the total number
of passes at the +10 oC level.

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