研究者詳細 - 山田　寛喜

論文 - 山田　寛喜

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IMPROVEMENT OF SCATTERING MODEL DECOMPOSITION BY ESPRIT-BASED POL-INSAR 査読

Hitoshi Onoda, Masahiro Yamazaki, Hiroyoshi Yamada, Yoshio Yamaguchi

Proc. of 2007 International Symposium on Antennas and Propagation (ISAP2007) 2007年8月

Coherent decomposition of polarimetric FMCW SAR data

Yoshio Yamaguchi, Muneyuki Ikarashi, Kazuyasu Aoyama, Jun Nakamura, Hiroyoshi Yamada

電子情報通信学会技術研究報告 SANE2007-61 ( 8 ) 19 - 23 2007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

This report presents a coherent decomposition scheme for high resolution polarimetric SAR data. This coherent decomposition here implies that the decomposition is applied to a single or a few scattering matrix data. Based on the polarimetric scattering matrix data obtained by an FM-CW ROLSAR system, we have devised a simple decomposition technique using the coherency matrix for purpose of identification of scatterer. This report presents a brief description of the decomposition method and some experimental results. It is shown the scattering mechanisms are well recovered and the orientation angle of wire target are precisely measured.

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POLSAR image analysis of Chuetsu-earthquake area using a modified four-component scattering power decomposition

山口芳雄, 矢島雄生, 佐藤亮一, 山田寛喜

電子情報通信学会技術研究報告 SANE2007-47 ( 8 ) 2007年8月

COMPUTATIONAL LOAD REDUCTION OF STAP USING A NEW STAGE PROCESSING 査読

Yoshikazu Shoji, Junichiro Suzuki, Hiroyoshi Yamada, Yoshio Yamaguchi, Masahiro Tanabe

Proc. of 2007 International Symposium on Antennas and Propagation (ISAP2007) 2007年8月

DOA推定のための仮想素子を用いたアレー校正法の効果

内藤孝, 山田寛喜, 山口芳雄

電子情報通信学会技術研究報告 AP2007-72 ( 7 ) 169 - 174 2007年7月

独立成分分析による分離信号を用いたアレー校正手法

島田裕平, 山田寛喜, 山口芳雄

電子情報通信学会技術研究報告 AP2007-73 ( 7 ) 175 - 180 2007年7月

Classification of Terrain Using the Correlation Coefficient in the Circular Polarization Basis for the X-band Pi-SAR image

山口芳雄, 山本ゆかり, 山田寛喜

電子情報通信学会技術研究報告 AP2007-26 ( 5 ) 75 - 80 2007年5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

Classification of terrain is one of the most important applications of Polarimetric Synthetic Aperture Radar (POLSAR) image analysis. This paper presents a simple method to classify terrain by the use of the correlation coefficients in the circular polarization basis together with the total power of the scattering matrix in the X-band. The reflection symmetry condition that the co-polarized and the cross-polarized correlations are close to zero for natural distributed scatterers is utilized to extract characteristic parameters of small forests or cluster of trees, and oriented urban building blocks in dependence of the direction of the radar illumination. Both of these kinds of scatterers are difficult to be identified in high resolution POLSAR images of complex urban areas. The indices employed here are the correlation coefficient, a modified coefficient normalized by the reflection symmetric conditional case, and the total power. It is shown that forest areas and oriented building blocks are so easily detected and identified. Then terrain is classified by these-combinations showing the result is corresponding well to the photographic ground truth images.

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複数給電型パラサイトアレーによる適応指向性制御について

森下雅透, Chen Sun, 太郎丸真, 山田寛喜, 大平孝

電子情報通信学会技術研究報告 AP2007 ( 5 ) 2007年5月

Optimal antenna matching and mutual coupling effect of antenna array in MIMO receiver 査読

Hiroki Iura, Hiroyoshi Yamada, Yasutaka Ogawa, Yoshio Yamaguchi

IEICE TRANSACTIONS ON COMMUNICATIONS E90B ( 4 ) 960 - 967 2007年4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

Antenna array is essential factor for multiple- input multiple-output (MIMO) wireless systems. Since the antenna array is composed of closely spaced elements, the mutual coupling among the elements cannot be ignored for the best performance of the array. Mutual coupling affects the MIMO channel, so the performance of a MIMO system, including channel capacity and diversity, varies with the degree of mutual coupling. The effect of mutual coupling is a function of the antenna load impedance. Therefore, designing an optimal element-matched array for a MIMO system requires consideration of the optimal matching condition for the array elements, the one that maximizes the channel capacity. We evaluated the effects of mutual coupling with various matching conditions in dipole arrays, and investigated their effects on the path correlation and channel capacity of MIMO systems. Simulation showed that the conventional conjugate matching of each element is still suitable for closely spaced elements except when the separation is about less than 0.1.1 Theoretical consideration of the received power of a closely-spaced-element array is also provided to show the effects of mutual coupling.

DOI： 10.1093/ietcom/e90-b4.960

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Classification of Targets on Road by Fully Polarimetric and Real-time FM-CW Radar 査読

J. Nakamura, M. Ikarashi, K. Aoyama, M. Mitamura, Y. Yamaguchi, H. Yamada, Y. Uehara

Progress In Electromagnetic Research Symposium Proceedings (PIERS) 60 2007年3月

仮想アレーを用いた拡張アレー校正法について

山田寛喜, 山口芳雄

電子情報通信学会総合大会 ( B-1-248 ) 2007年3月

Polarimetric Observation of the Trees in the X- and Ku-band by FM-CW SAR system 査読

K. Aoyama, M. Ikarashi, J. Nakamura, Y. Yamaguchi, H. Yamada

Progress In Electromagnetic Research Symposium Proceedings (PIERS) 61 2007年3月

Classification of stricken residential houses by the Mid Niigata Prefecture Earthquake based on POLSAR image analysis 査読

Ryoichi Sato, Koji Soma, Yuki Yajima, Yoshio Yamaguchi, Hiroyoshi Yamada

IGARSS: 2007 IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOLS 1-12 200 - + 2007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：IEEE

This report attempts to apply a hybrid classification technique based on POLSAR image analysis to detect the man-made residential houses in a local mountainous area stricken by the Mid Niigata Prefecture Earthquake. The present hybrid scheme includes the scattered power decomposition method based on physical scattering nature and the scattering feature extraction method using polarimetric correlation coefficient. From the results of the image analysis for actual POLSAR data, it is verified that the present hybrid scheme provides us accurate classification of the man-made targets even in the severe mountainous area.

DOI： 10.1109/IGARSS.2007.4422764

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An efficient dimensional reduction of the blocking matrix for the multistage Wiener filter 査読

Junichiro Suzuki, Yoshikazu Shoji, Hiroyoshi Yamada, Yoshio Yamaguchi, Masahiro Tanabe

CONFERENCE RECORD OF THE FORTY-FIRST ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS & COMPUTERS, VOLS 1-5 592 - + 2007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：IEEE

The multistage Wiener filter (MWF) is a powerful adaptive processing in low sample support environments. Because the MWF solution is provided by a stage-by-stage decomposition, the computational load increases depending on degrees-of-freedom (DOF). In this paper, we propose two efficient approaches by reducing dimensions of the blocking matrix. One approach is to delete some rows of the blocking matrix at the 1st stage, and following stages are calculated by the normal method. The second approach is to delete some rows at all stages consistently. Although the MWF adaptive process of the proposed approaches must be stopped at the optimum stage to avoid a performance degradation, it was solved by applying a simple stopping criterion based on a cross-correlation coefficient. The performance was evaluated by simulation examples, examining the effectiveness.

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Coherence enhancement for polarimetric SAR interferometry 査読

Tao Xiong, Jian Yang, Weijie Zhang, Yoshio Yamaguchi, Hiroyoshi Yamada

PIERS 2007 BEIJING: PROGRESS IN ELECTROMAGNETICS RESEARCH SYMPOSIUM, PTS I AND II, PROCEEDINGS 45 - + 2007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：ELECTROMAGNETICS ACAD

A new method for coherence enhancement is proposed based on the mathematical model on the relationship between the amplitude and the phase of the complex signals. An optimal projection direction of scattering vectors is derived for maximizing the amplitudes of the master and slave complex images. The experimental results demonstrate the effectiveness of the proposed approach.

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Blind array calibration technique for uniform linear array using ICA 査読

Yuhei Shimada, Hiroyoshi Yamada, Yoshio Yamaguchi

TENCON 2007 - 2007 IEEE REGION 10 CONFERENCE, VOLS 1-3 175 - 178 2007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：IEEE

This paper develops a technique for estimating the array calibration matrix using signal sources with unknown direction-of-arrivals (DOAs). These signal sources can be separated by the independent component analysis (ICA). In the proposed calibration technique, the calibration matrix is estimated with these separated signal sources. Iterative estimation is employed for the estimation since DOA of the signal source is unknown. The validity of the proposed calibration technique is examined by computer simulations.

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Handheld direction of arrival finder with electronically steerable parasitic array radiator using the reactance-domain MUltiple SIgnal Classification algorithm 査読

A. Hirata, E. Taillefer, H. Yamada, T. Ohira

IET Microwaves, Antennas and Propagation 1 ( 4 ) 815 - 821 2007年

記述言語：英語掲載種別：研究論文（学術雑誌）

Reactance-domain MUltiple SIgnal Classification (RD-MUSIC) is a promising scheme for enabling ESPAR (Electronically Steerable Parasitic Array Radiator) antennas to accurately estimate the DOAs (directions-of-arrival) of radio waves. The ESPAR antenna is a variable directional antenna designed for battery-operated mobile terminals, and is utilised for handheld DOA finder applications as well as for wireless communication systems. We present some experimental results showing that the RD-MUSIC with a conventional calibration obtains a sharp spectrum for accurate DOA estimation, although the ESPAR antenna is equipped with only a single-port output unlike a conventional array antenna. The results also demonstrate that RD-MUSIC works well even when exploiting fewer beam patterns than the number of antenna elements. Moreover, we have verified that a human body hardly generates any degradation of DOA estimation even holding the DOA finder close to the body. The degradation of DOA estimation because of a human body is kept to less than about 6°, and removing beam patterns towards directions of reflections from the human body is found to be useful in decreasing the errors. Although the reduction in the number of beams results in reducing the total number of estimated waves, it can mitigate the influence of a human body for actual DOA estimation with the handheld DOA finder. © The Institution of Engineering and Technology 2007.

DOI： 10.1049/iet-map:20050152

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Rank Selection Algorithm with a Cross-Correlation Coefficient for the Multistage Wiener Filter 査読

Junichiro Suzuki, Yoshikazu Shoji, Hiroyoshi Yamada, Yoshio Yamaguchi, Masahiro Tanabe

Proc. of 2006 International Symposium on Antennas and Propagation (ISAP2006) 2006年11月

Seasonal Change Investigation of Water Area in Lake Sakata Based on POLSAR Image Analysis 査読

Ryoichi Sato, Yuki Yajima, Yoshio Yamaguchi, Hiroyoshi Yamada

Proc. of 2006 International Symposium on Antennas and Propagation (ISAP2006) 2006年11月

Simple Calibration Technique for Arrays with Single-mode Elements Based on Mutual Impedance Matrix 査読

Hiroyoshi Yamada, Masayuki Morishita, Yoshio Yamaguchi

Proc. of 2006 International Symposium on Antennas and Propagation (ISAP2006) 2006年11月

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