Information Technology Reference
In-Depth Information
H
x
o
E
N(1)
E
N(2)
={
(
z
)
Z
N
(
z
)
,
0
,
0
}
={
0
,
−
(
z
)
Z
N
(
z
)
,
0
}
H
yo
(5
.
17)
H
N(1)
={
(
z
)
,
0
,
0
}
H
N(2)
={
0
,
(
z
)
,
0
}
and a source-effect mode with the vertical magnetic component and linear variations
of the horizontal components along the Earth's surface:
⎧
⎨
i
o
y
(
z
)
Z
N
(
z
)
2
Z
N
(0)
i
o
x
(
z
)
Z
N
(
z
)
2
Z
N
(0)
E
N(3)
={−
,
,
0
}
H
z
o
(5
.
18)
i
o
x
(
z
)
2
Z
N
(0)
i
o
y
(
z
)
2
Z
N
(0)
(
z
)
Z
N
(
z
)
Z
N
(0)
⎩
H
N(3)
={−
,
−
,
}
.
Modes
E
N(1)
H
N(1)
,
E
N(2)
H
N(2)
and
E
N(3)
H
N(3)
contain normalized
,
,
,
fields that satisfy the conditions:
E
N(1)
(
x
=
0
,
y
=
0
,
z
=
0)
={
0
,
−
Z
N
(0)
,
0
}
,
E
N(2)
(
x
=
0
,
y
=
0
,
z
=
0)
={
Z
N
(0)
,
0
,
0
}
,
E
N(3)
(
x
=
0
,
y
=
0
,
z
=
0)
={
0
,
0
,
0
}
,
H
N(1)
(
x
=
0
,
y
=
0
,
z
=
0)
={
1
,
0
,
0
}
,
H
N(2)
(
x
=
0
,
y
=
0
,
z
=
0)
={
0
,
1
,
0
}
,
H
N(3)
(
x
=
0
,
y
=
0
,
z
=
0)
={
0
,
0
,
1
}
.
An arbitrary normal field is the superposition of all three modes:
H
x
o
E
N(1)
H
y
o
E
N(2)
H
z
o
E
N(3)
E
N
=
+
+
,
(5
.
19)
H
xo
H
N(1)
H
y
o
H
N(2)
H
z
o
H
N(3)
H
N
=
+
+
,
where
H
x
o
,
H
y
o
,
H
z
o
are values of the normal magnetic fields at the origin of the
coordinates:
H
N
(
x
H
x
o
,
H
y
o
,
H
z
o
}
.
=
0
,
y
=
0
,
z
=
0)
={
(5
.
20)
In the general case when all three modes are available on the Earth's surface
we get
E
y
(
z
=
0)
E
x
(
z
=
0)
Z
N
(0)
=
0)
=−
(5
.
21)
H
y
(
z
=
H
x
(
z
=
0)
and
H
z
=
(
z
0)
Z
N
(0)
=−
i
o
.
(5
.
22)
H
y
(
z
=
0)
H
x
(
z
=
0)
+
x
y
