Scientific Study of Unidentified Flying Objects (the Condon Report, complete, three volumes)

A(z) = N(z) + ~13 [1 - exp{-O.14386z}];
here N(z) is the actual refractivity profile, a function of height, z,
in kilometers I find the last term -represents the average decrease ".lth
he ... glit of an average radio refractivity profi Ie
Nez) = 313 exp{-O.14386z}.
The number 313 is an average surface refr&ctivity value. An N-profile
that is not abnormal will, when plotted on a graph with A(z) as abscissa
and z as ordinate, appear as a fairly straight vertical line, perhaps
with a slight tilt in one direction or the other. On the other hand,
an N-profile with strongly super-n'fractive or subrefractive
display a marked zigzag character on an A(z) vs. z plot. The use of
A-units allows a more generous sc~le size for the abscissa than ~ould
be the case for N-unit plots.
Ray tracings, calculated and plotted by a digital computer, are
illustrated for a few of the refractivity profiles. 'nlC computer
also calculates the M-profile, and plots it on the same graph as the
ray tracing. M-units are defined by
M(z) = N(z) + ~ •
a
where "a" is the radius of the earth. This is equivalent to adding
156.9 N-units per km. to the observed prof~le. Since the ducting gradient
(see Chapter VI --4) is -156.9 N. km- 1 , any layer with such a gradient
wi 11 be represented on an M(z) plot as a vertical line. Layers with
dN/dz > -156.9 km- 1 (not ducting) will show a trace slanting up to the
1
right, whereas strong ducts with dN/dz -156.9 km (not ducting) will show a trace slanting up to the
1
right, whereas strong ducts with dN/dz ~ -156.9 km-· will show a trace
slanting up to the left. ilence the M-unit plo;- is very convellient fOT
exposing the existence or non-existence of radio ducts in N(z) data.
!" AnalysiS of Selected UFO Incidents by Cla~:ses:
In the discussions bat follow the UFO incidents are referred to
by the case numbers assigned to them in the UFO project files. TIle
17i