研究者詳細 - 山田　寛喜

論文 - 山田　寛喜

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Stable Decomposition of Mueller Matrix

楊健, 山口芳雄, 山田寛喜

電子情報通信学会技術研究報告 AP97-91 ( 8 ) 29 - 34 1997年8月

記述言語：英語出版者・発行元：一般社団法人電子情報通信学会

Huynen has provided a method to decompose a Mueller matrix into an average single target and a N-target (non-symmetric target and noises) in order to retrieve detailed target information. However, the decomposition sometimes fails in the presence of small error or noise in the elements of Mueller matrix. This paper attempts to improve Huynen's decomposition method. First, the definition of a stable decomposition is given, showing the importance and a problem of Huynen's approach by an example. Then a method is proposed to carry out stable decomposition, based on the Least Squares Method and the Newton's Method. Stability means the decomposition is not sensitive to errors. The proposed methods overcomes the problems on the unstable decomposition of Mueller matrix. Finally, two numerical examples are given, showing our method is superior to the methods of Huynen and Pottier.

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地中探査用T-barスロットアンテナのFDTD法解析

炭篤則, 脇田喜之, 山田寛喜, 山口芳雄, 藤本京平

電子情報通信学会技術研究報告 AP97-86 ( 8 ) 1997年8月

改良型Root-MUSIC法を用いた電磁波散乱の周波数分散性検出について

板羽直人, 山田寛喜, 山口芳雄

電子情報通信学会技術研究報告 AP97-79 ( 7 ) 61 - 67 1997年7月

記述言語：日本語出版者・発行元：一般社団法人電子情報通信学会

スーパーレゾリューションの高分解能性は電磁波散乱の局所散乱現象の解析に有効である. 本稿では, 周波数分散性を有する散乱波が含まれる円形導波管からの後方散乱に対する改良型Root-MUSIC法の適用について検討している. 特に, 補正方法として考えられる前処理方式, 後処理方式を比較し, 後処理方式の優位性を示している. 更に, 時間領域ノッチフィルタを併用することにより推定精度の向上が図られることを数値計算, 及び実験により明らかにしている.

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On the classification of objects buried in the underground by radar polarimetry

森山敏文, 中村政文, 山口芳雄, 山田寛喜

電子情報通信学会技術研究報告 AP97-68 ( 7 ) 65 - 71 1997年7月

校正用平行平板ターゲットによるPolarimetry calibrationの検討

北山健志, 山口芳雄, 山田寛喜

電子情報通信学会技術研究報告 AP97-69 ( 7 ) 1997年7月

High-resolution scattering center estimation using polarization averaging MUSIC algorithm

山田寛喜, 山倉利春, 山口芳雄

電子情報通信学会技術研究報告 AP97-77 ( 7 ) 45 - 52 1997年7月

記述言語：英語出版者・発行元：一般社団法人電子情報通信学会

近年, リモートセンシング, 電波伝搬推定等において, 偏波を含めた高精度・高分解能推定が注目されている. フーリエ変換法などでは実現不可能な高分解能性を有する手法として知られるスーパレゾリューション法においても, 偏波情報の利用に関する報告がいくつかなされている. 本論文では, スーパーレゾリューション法での新たな偏波データ利用法として偏波平均化相関抑圧前処理を提案し, その動作条件, 相関抑圧性能に関する理論的考察を行っている. その結果, 本手法では, 1)入射波の偏波の相違を相関抑圧に利用, 2)より少ないサブアレー数での信号の分離検出が可能などの利点を有することを明らかとなった. また, 本手法をMUSIC法に適用した数値計算, 実験結果についても示し, その有効性を実証している.

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An equivalent sensitivity time control circuit for FM-CW radar 査読

H Kasahara, T Moriyama, Y Yamaguchi, H Yamada

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS 80 ( 6 ) 1 - 7 1997年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SCRIPTA TECHNICA-JOHN WILEY & SONS

Typical problems for subsurface radar sensing are the existence of strong surface clutter and the difficulty in detection of deep targets due to the attenuation of electromagnetic waves underground. This paper proposes a method of enhancing deep target echo strength for FM-CW radar so that the radar sensitivity is proportional to the range. This technique is similar to the time sensitivity control circuits used for pulse radar, and is based on the differentiation property of the beat signal with respect to time. First, we show that this amplitude compensation approach is feasible both theoretically and experimentally in free space. Next, the validity of this method is confirmed by a subsurface target detection experiment using sandy ground. Finally a hardware implementation in the FM-CW radar is described. (C) 1997 Scripta Technica, Inc.

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Polarization anisotropy係数による埋没物体の分類

森山敏文, 山口芳雄, 山田寛喜

電子情報通信学会総合大会 ( B-1-46 ) 1997年3月

スーパレゾリューション法による高分解能ポーラリメトリックイメージング

山田寛喜, 大西和則, 山口芳雄

電子情報通信学会総合大会 ( B-1-44 ) 1997年3月

Radar polarimetry applied to the classification of target buried in the underground 査読

T Moriyama, M Nakamura, Y Yamaguchi, H Yamada, WM Boerner

WIDEBAND INTERFEROMETRIC SENSING AND IMAGING POLARIMETRY 3120 ( 3120-13 ) 182 - 189 1997年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：SPIE-INT SOC OPTICAL ENGINEERING

This paper discusses the classification of target buried in the underground by the radar polarimetry. The subsurface radar is used in the detection of objects buried beneath the ground surface, such as archeological exploration, pipes, gas cables and cavities. However, in addition to target echo, the subsurface radar receives various echoes including clutter, because the underground is inhomogeneous medium. Therefore, the subsurface radar needs the ability to distinguish these echoes. In order to enhance the ability, we first applied the polarization anisotropy coefficient to classify the echo into isotropic target (plate, sphere) and anisotropic target (wire, pipe). It is easy to find the man-made target buried in the underground by polarization anisotropy coefficient. Second, we used a three-component decomposition technique for a scattering matrix. Third, we tried to classify targets using polarimetric signature approach. Moreover, the characteristic polarization state gives the oriented angle of anisotropic target. Therefore, these values contribute the classification of the target. The field experiments using an FM-CW radar system were carried out to show the usefulness of the radar polarimetry. In this paper, several detection and classification results are displayed. It is shown that these techniques improve the detection capability of buried target.

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Polarimetric superresolution technique for 2-D radar target imaging 査読

H Yamada, K Onishi, Y Yamaguchi

WIDEBAND INTERFEROMETRIC SENSING AND IMAGING POLARIMETRY 3120 ( 3120-23 ) 317 - 326 1997年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：SPIE-INT SOC OPTICAL ENGINEERING

Recently, estimation and resolution improvements utilizing the polarization information of electromagnetic wave have been attracting attention in remote sensing and indoor radio propagation analyses. High-resolution technique based on the modern spectral estimation method is one of the promising methods to realize high resolution and accurate estimation capabilities. Several modifications for the technique using the polarization data have reported. Ln this paper, we propose a new modification for the technique concerning with decorrelation preprocessings, and show its availability for microwave imaging. The method has two main advantages compared with the conventional one; 1) improved decorrelation performance, 2) increased the number of resolvable signals (scattering centers). The resolution improvement is verified theoretically and experimentally.

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Resolution improvement of the MUSIC algorithm utilizing two differently polarized antennas 査読

T Yamakura, H Yamada, Y Yamaguchi

IEICE TRANSACTIONS ON COMMUNICATIONS E79B ( 12 ) 1827 - 1832 1996年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG

Recently, a short range millimeter wave or a microwave sensing system has been extensively studied to estimate a target position or a source location. It can be applied to indoor propagation analysis, carborne applications, etc. The application of the superresolution technique has been proposed to obtain a high resolution performance in the time domain or the spatial domain. However, the availability of the polarization synthesis in the receiving antennas has not been considered. In this paper, we use a pair of polarized swept frequency data and propose two modifications of the MUSIC algorithm to enhance the resolution of time delay. One modification is the correlation matrix formulation which relates to the total signal power, and the other is a polarization filtering applied to the correlation matrix. These modifications have advantages such that: I) Reduction of the estimation problem to the delay time estimation only; 2) Easy implementation. Experimental results are illustrated to show the availability of the methods, and to confirm the high resolution performance compared with the conventional method.

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FM-CWレーダにおける等価STC回路について査読

笠原一, 森山敏文, 山口芳雄, 山田寛喜

電子情報通信学会論文誌B-II J79-B-II ( 9 ) 583 - 588 1996年9月

Polarimetric detection of objects by a deep sounding FM-CW radar 査読

Y.Yamaguchi, H.Kasahara, T.Moriyama, H.Yamada

Proc. of International Symposium on Ground Penetrating Radar 373 - 376 1996年9月

An equivalent time sensitivity control technique for polarimetric FM-CW radar 査読

T.Moriyama, H.Kasahara, Y.Yamaguchi, H.Yamada

Proc. of International Symposium on Antennas and Propagation (ISAP'96) 4 ( 4 ) 1053 - 1056 1996年9月

Polarimetric calibration for a synthetic aperture FM-CW radar 査読

Y.Yamaguchi, Y.Takayanagi, H.Yamada

Proc. of International Symposium on Antennas and Propagation (ISAP'96) 4 ( 4 ) 1049 - 1052 1996年9月

A new method to obtain the optimal polarization states in the co-polarized channel 査読

J.Yang, Y.Yamaguchi, H.Yamada

Proc. of International Symposium on Antennas and Propagation (ISAP'96) 4 ( 4 ) 1029 - 1032 1996年9月

MUSIC algorithm for the delay time and the polarization estimation 査読

H.Yamada, T.Yamakura, Y.Yamaguchi

Proc. of International Symposium on Antennas and Propagation (ISAP'96) 3 ( 3 ) 737 - 740 1996年9月

A new method for characterizing radar target 査読

J.Yang, Y.Yamaguchi, H.Yamada

Proc. of International Symposium on Antennas and Propagation (ISAP'96) ( 4 ) 1029 - 1032 1996年9月

ホーンアンテナを用いたFM-CWレーダにおける分解能劣化補正の検討

笠原一, 山口芳雄, 山田寛喜

平成８年度電子情報通信学会信越支部大会 ( V-14 ) 27 - 28 1996年9月

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