| Co-Investigator(Kenkyū-buntansha) |
孟 志奇 福岡大学, 工学部, 助教授
MATSUOKA Tsuyoshi Faculty of Information Science and Electrical Engineering, Research Associate, 大学院・システム情報科学研究院, 助手 (40325551)
FUJISAKI Kiyotaka Faculty of Information Science and Electrical Engineering, Associate Prof, 大学院・システム情報科学研究院, 助教授 (20253487)
MENG Zhi qi Fukuoka University, Faculty of Engineering, Associate Prof.
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| Research Abstract |
Research results of subjects planed at the first stage of this project are summarized.
1. Exact evaluation of RCS of conducting targets with convex-concave cross sections when they are surrounded by turbulent media and random media containing many particles.
(1.1) In turbulent media, using the method presented by us, we exactly evaluate the bistatic RCS
(1.a) in the case that the spatial coherence length of incident wave around the target C is larger than the size of target D and also show interesting RCS characteristics surpassed expectations and the cause.
(1.b) In case of C 〜 D and C < D, we need a vector processor to get the numerical results.
(1.2) In random media containing many particles,
(2.a) to evaluate the scattering by more than ten thousand particles, we present a fast multiple method which currently has minimums of both asymptotic orders of computation time and memory requirement. Numerical data on the scattering are obtained.
(2.b) Analyzing a vector radiative transfer equation, we evaluate the RCS and present a microwave sensing method for estimating a water content in soil.
2. Investigation of scattering by targets in random media, compared with that in free space at the wave beam incidence.
The similarity or difference in behavior between both monostatic RCS in random media and in free space occurs according as C > D or C 〜 D and C < D.
3. Evaluation of angular memory effects in the scattering by targets in random media.
In case of C > D, the effects depend only on the random media ; on the other hand, they are not evaluated in case of C 〜 D and C < D because of much computation time.
4. Investigation of the scattering matrix for random media.
The computer simulation of (2.a) produces the scattering matrix and the analysis of (2.b) does numerically the Stokes matrix of 4 by 4.
From above results, we present a method of detection and imaging of targets in random media, the accuracy of which method does not become worse than that in free space.
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