US 2025/0232084 A1Published application

Efficient method for solving electromagnetic field of radiation source layer in layered lossy medium

AssigneeNorthwestern Polytechnical University

InventorsHonglei WANG, Yulong WEI, Yingda REN

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Abstract

In an efficient method for solving the electromagnetic field of the radiation source layer in the layered lossy medium, the secondary field is obtained by selecting the amplitude coefficient from the interface of the radiation source layer, and then superimposed with the background field to obtain the electromagnetic field of the radiation source layer. Due to the minimum difference in the amplitude coefficient from the interface of the radiation source layer, this method has lower requirements on the integration interval and the number of sampling points, and the background field can be directly obtained by the theoretical formula. The method significantly reduces overall memory usage and computation time, thereby improving computational efficiency. The method lowers the computational cost of solving the electromagnetic field of the radiation source layer in a layered lossy medium, enhances the model's solution efficiency, and supports the effective development of marine electromagnetic detection and related research.

An efficient method for solving an electromagnetic field of a radiation source layer in a layered lossy medium, comprising the following steps:

step 1:
expressing an electromagnetic field of a radiation source layer in a layered lossy medium model as a superposition of Transverse Electric (TE) and Transverse Magnetic (TM) waves, and establishing an electromagnetic field expression of each electromagnetic field component;
step 2:
according to boundary conditions of the electromagnetic field, a propagation matrix, and a dipole antenna type, obtaining amplitude coefficients of the radiation source layer when z≥0:
{
A
0
+
=
[
ε
0
*
⁢
ξ
-
1
+
ε
-
1
*
⁢
ξ
0
+
(
ε
-
1
*
⁢
ξ
0
-
ε
0
*
⁢
ξ
-
1
)
⁢
e
-
j
⁢
2
⁢
ξ
0
⁢
d
0
]
⁢
E
h
⁢
m
⁢
d
ε
0
*
⁢
ξ
-
1
+
ε
-
1
*
⁢
ξ
0
-
(
ε
1
*
⁢
ξ
0
-
ε
0
*
⁢
ξ
1
)
⁢
(
ε
-
1
*
⁢
ξ
0
-
ε
0
*
⁢
ξ
-
1
)
ε
1
*
⁢
ξ
0
+
ε
0
*
⁢
ξ
1
⁢
e
j
⁢
2
⁢
ξ
0
(
d
1
-
d
0
)
B
0
+
=
A
0
+
⁢
(
ε
1
*
⁢
ξ
0
-
ε
0
*
⁢
ξ
1
ε
1
*
⁢
ξ
0
+
ε
0
*
⁢
ξ
1
)
⁢
e
j
⁢
2
⁢
ξ
0
⁢
d
1
C
0
+
=
[
μ
0
⁢
ξ
-
1
+
μ
-
1
⁢
ξ
0
-
(
μ
-
1
⁢
ξ
0
-
μ
0
⁢
ξ
-
1
)
⁢
e
-
j
⁢
2
⁢
ξ
0
⁢
d
0
]
⁢
H
h
⁢
m
⁢
d
μ
0
⁢
ξ
-
1
+
μ
-
1
⁢
ξ
0
-
(
μ
1
⁢
ξ
0
-
μ
0
⁢
ξ
1
)
⁢
(
μ
-
1
⁢
ξ
0
-
μ
0
⁢
ξ
-
1
)
μ
1
⁢
ξ
0
+
μ
0
⁢
ξ
1
⁢
e
j
⁢
2
⁢
ξ
0
(
d
1
-
d
0
)
D
0
+
=
C
0
+
⁢
(
μ
1
⁢
ξ
0
-
μ
0
⁢
ξ
1
μ
1
⁢
ξ
0
+
μ
0
⁢
ξ
1
)
⁢
e
j
⁢
2
⁢
ξ
0
⁢
d
1
wherein A0+, B0+, C0+ and D0+ denote the amplitude coefficients of the radiation source layer when z≥0;
ξl=(kl2−kρ2)0.5, kl is a propagation constant, εl* is a complex dielectric constant, and μl is a permeability in an l-th layer;
Ehmd=ISωμ0kρ2/8πξ0 and Hhmd=−ISkρ2/8π, and IS is a magnetic dipole moment;
the amplitude coefficients of the radiation source layer when z≤0:
{
A
0
-
=
A
0
+
-
E
h
⁢
m
⁢
d
B
0
-
=
B
0
+
+
E
h
⁢
m
⁢
d
C
0
-
=
C
0
+
-
H
h
⁢
m
⁢
d
D
0
-
=
D
0
+
-
H
h
⁢
m
⁢
d
step 3:
selecting A0+, B0−, C0+, and D0− with smallest amplitude differences and substituting A0+, B0−, C0+, and D0− with the smallest amplitude differences into the electromagnetic field expression to solve each electromagnetic field component, and obtaining a secondary field composed of lateral waves and reflected waves from upper and lower interfaces of the radiation source layer;
and
step 4:
performing a vector sum of the secondary field and a background field to obtain each component of a total electromagnetic field in the radiation source layer.

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Abstract

Claims12