height to rise was noted in several sequential groups.
Consequently,
a plot was made with the minimm height of each group represented by a
cross (Fig. 3.19).
A possible explanation for the increasing heights
was immediately seen. The hypothesis is that the rising sequences
of points resulted from regions of relatively intense ionization mov~
(The anten- |
' yas, though designed for vertical radiation and reception, are not.
restricted 40 thie direction, and oblique returns are often encount-.
ered when horizontal inhomogeneities are present in the ionosphere. —
The "height" at which such echoes appear is greater by virtue of the
eae path length and is, hence, called “apparent height" in Fig. .
3e19-
KM
aes
'
57,.+73M
60.+84M
800
600
400 Sh
200
TPES
59.+81M
ere
KM
fs
Ol +90M
2)
£4. £
eT
tee
coe
te
+
brs geet
———
SESE
t
¢
e
. t+
ts
TEE
aa
=, Litt
Dol?
$6.479M
62.+95M
SPER PS eee
800
600
400
200 ~
o
2
3
4
6
8
10
i@
CE
2
3
4
6
8
10
14
Fig. 3.16 = Ionospheric Records at Rongerik Following Shot 4 by 73 to
95 min, Showing Clearly Oblique Echoes and Trend Toward
Nornaloy
45
SECRET
mC
~
ing horizontally in some direction away from the operating site as
part of a radial motion originating above the explosion,