The document presents a new method called the current generator method (CGM) for simulating electromagnetic scattering from conductive targets. CGM uses spherical harmonic decomposition to represent the induced surface currents on targets. This allows for a fast calculation of backscatter compared to existing techniques like the method of moments. The document outlines existing simulation techniques, motivates the need for a new method due to limitations of current approaches, describes how CGM works using spherical harmonics and Huygen's principle, and proposes validating CGM through demonstrating its formulation, computation time, and accuracy compared to other techniques.
4. Areas of Focus
RE-
ASU T
ME EN
M
HER
W EAT
NSE
D EFE
ati o ns
Ap plic
Img src: Raytheon 4
newspaper.li, Peteryu.com
5. For this Presentation:
1. WHY SIMULATE?
2. HOW TO SIMULATE
Outline
3. A NEW WAY TO SIMULATE
4. PROVING THE METHOD
5
6. 1. WHY SIMULATE?
1.1 System Complexity
1.2 Target Complexity
2. HOW TO SIMULATE
2.1 The Scattering Process
2.2 Current Density
2.3 Physical Optics
2.4 Finite Differences
2.5 Integral Equations / M.O.M.
2.6 Linear Solutions
3. A NEW WAY TO SIMULATE
3.1 The Current Generator Method
3.2 Spherical Harmonics
3.3 Formulation
3.4 Random Media
4. PROVING THE METHOD
4.1 Thesis Roadmap
6
20. 2.6 Solving System ( Z a = b )
BiCG
GAUSS [3]
ELIM. AIM
Conj. [6]
Gradient
[1] [2]
CGS
[4]
SOLUTION
FMM
[7]
MLFMA
LU [8]
DECOMP.
FFT
[5]
N 3
N 2 N logN
N - # patches 20
21. 2.6 Solving System ( Z a = b )
BiCG
GAUSS [3]
[1] Stratton ’81
ELIM. AIM
Conj.
Gradient [2] Sarkar [6]
’86
[1] [2]
CGS [3] Lanczos ’52
[4]
SOLUTION [4] Sonneveld ‘89
FMM
[5] Sarkar [7]
’86
MLFMA
LU [6] Bleszynski ‘96 [8]
DECOMP.
FFT Coifman ’93
[7]
N 3 N 2 [5]
N
[8] Song ‘97 logN
N - # patches 21
22. Part 3: A New Way to Simulate:
The Current Generator Method
22
26. 3.3 Current Generator Operator
Orthogonal Huygen’s Divergence Harmonic
Harmonics [1] Theorem Coefficients
BOUNDARY INCIDENT
CONDITIONS FIELD
[1] Ishimaru, 1991 26
Image: Wikipedia (ripple tank)
27. 3.3 Final Result
REVISED CURRENT GENERATOR METHOD
G. Togtema, H. El-Ocla, “Fast Calculation of 3D Conductive Target
Backscatter…” submitted to IEEE Antennas and Prop.
27
28. 3.3 Others who have used
Spherical Harmonics
FMM + SPHER. HARM. [Eibert 2005]
LITERATURE PATTERN EQ’N METHOD [Kyurkchan 00]
APPLICATIONS OF MIE THEORY
28
29. 3.4 CGM and Random Media
K
ENCE ACTER
B T
INCID SCA
( To Coherent Detector )
See: Wolf 2002 29
(J. Opt. Soc. Am)
30. 3.4 The Effects of Random Media
Gain due to R.M.
SHAPE
A
Function
POLAR-
of… IZATION
CREEP. R.M.
WAVES Figure: Scattering
normalized w.r.t. no
random media as a
function of wave number,
Image: (k) 30
El-Ocla, 2007
31. Part 4: Proving the Current
Generator Method
31
32. 4.1 CGM Roadmap
CGM Formulation
Functional Computation Accuracy
Demonstration Time
Image: A. Sourin. 32
SV Journal (2010)
