研究者詳細 - 山田　寛喜

論文 - 山田　寛喜

分割表示 893 件中 641 - 660 件目／全件表示 >>

Scattering characteristic analysis of conifer and broad-leaf trees by polarimetric radar 査読

Y. Yamaguchi, M. Murase, H. Yamada

Proc. of EMEA 18 - 27 2001年9月

3-D mode method for wave propagation estimation 査読

H.Yamada, T.Nakazawa, Y.Yamaguchi

Proc. of KJJC 23 - 26 2001年9月

Complex permittivity of flat ground in terms of polarization ratio 査読

Y. Yamaguchi, K. Kimura, H. Yamada, H. J.Eom

Proc. of KJJC 19 - 22 2001年9月

MODE法に基づく3次元波源探査法について

山田寛喜, 中澤達也, 山口芳雄

電子情報通信学会ソサイエティ大会 ( SB-1-10 ) 553 - 554 2001年9月

Covariance行列を用いた偏波較正とPI-SAR画像解析

木村晃治, 山口芳雄, 山田寛喜

電子情報通信学会ソサイエティ大会 ( B-1-29 ) 35 2001年9月

PI-SAR Image Analyses 査読

Y. Yamaguchi, K. Kimura, H. Yamada

AP-RASC, 2001 165 2001年8月

Dual Polarization SAR Interferometry for Vegetation Analysis 査読

H.Yamada, Y.Yamaguchi, E.Rodriguez, Y.Kim, W.M.Boerner

AP-RASC, 2001 166 2001年8月

Development of T-bar Fed Slot Antenna with Taper Matching Section 査読

Y.Wakita, S.Watabe, H.Yamada, Y.Yamaguchi

Progress In Electromagnetic Research Symposium Proceedings (PIERS) 625 2001年7月

Polarimetric correlation coefficient applied to tree classification 査読

M. Murase, Y. Yamaguchi, H. Yamada

Progress In Electromagnetic Research Symposium Proceedings (PIERS) 272 2001年7月

Polarimetric calibration of PI-SAR image data and its image analysis 査読

K. Kimura, Y. Yamaguchi, H. Yamada

Progress In Electromagnetic Research Symposium Proceedings (PIERS) 271 2001年7月

The estimation error in 2D superresolution techniques 査読

R. Hara, T. Nakazawa, H. Yamada, Y. Yamaguchi

Progress In Electromagnetic Research Symposium Proceedings (PIERS) 683 2001年7月

Polarimetric SAR Interferometry for Vegetation Analysis Using ESPRIT Algorithm 査読

Hiroyoshi Yamada, Yoshio Yamaguchi, Ernesto Rodriguez, Yunjin Kim, W.M.Boerner

Progress In Electromagnetic Research Symposium Proceedings (PIERS) 267 2001年7月

On polarimetric coherency matrix in optimized POL InSAR image 査読

K. Sato, H. Yamada, Y. Yamaguchi

Progress In Electromagnetic Research Symposium Proceedings (PIERS) 266 2001年7月

Radar Polarimetryによる木々の散乱特性の解析

村瀬誠, 山口芳雄, 山田寛喜

電子情報通信学会技術研究報告 AP2001-22 ( 5 ) 2001年5月

Development of target null theory 査読

J Yang, Y Yamaguchi, H Yamada, WM Boerner, H Mott, YN Peng

IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 39 ( 2 ) 330 - 338 2001年2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：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

In a co- or cross-polarized channel, the polarization states of the transmitting and receiving antennas are the same or orthogonal, and the corresponding target nulls (i.e., the CO-POL Nulls or X-POL Nulls) are defined as the polarization states of the transmitting antenna such that the received power equals zero. However, no systematic studies have been carried out to solve the problem of the corresponding target nulls if the polarization states of the transmitting and receiving antennas are independent. In this paper, the target null theory is extended to the case of two independent polarization states. For two arbitrary independent symmetric scattering matrices, it is proved that there exists only one pair of polarization states such that both of the received powers equal zero. This polarization states' pair is called the co-null of the two targets, which can easily be obtained by solving an eigenvalue problem. Based on this concept and algebraic theory, the concept of the co-null space is introduced for the symmetric scattering matrix case, and many important results are presented, e.g., the relations between the co-null and the CO-POL/X-POL Nulls, the properties of the co-null space, and the relation between the co-null and target decomposition. Finally, the co-null for the asymmetric scattering matrix case is studied. The concepts of the mono-co-null space and the bi-co-null space are introduced, and the relations between both spaces are presented.

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EM-MODE法を用いた不等間隔アレーにおける多重波の到来方向推定査読

中澤達也, 山田寛喜, 山口芳雄

電子情報通信学会論文誌B J84-B ( 1 ) 92 - 100 2001年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：電子情報通信学会

近年，移動通信や各種無線通信のための電波伝搬環境の高分解能推定手法としてスーパレゾリューション法が注目されている．また，到来方向推定問題で用いられるアレー形状に関しても，等間隔アレーに限定せず，様々なアレー配置に対する検討が試みられている．Weissらにより，不等間隔に並べられたアレーに対してEM法とIQML法を適用し，仮想的な等間隔アレーを実現する手法が提案されているが，本論文では，このアルゴリズムに基づいたEM-MODE法を用いて，不等間隔アレーによるコヒーレント波の到来方向推定，及び改善処理の提案を行っている．そして，従来のEM-MODE法では推定が困難な場合に対して，改善処理を適用することにより，推定成功確率の向上が可能となることを示している．また，本手法を適用した場合の到来方向推定誤差について検討を行い，実在素子を等間隔に配置した場合と比較して，優れた特性を有することを示している．

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その他リンク： http://hdl.handle.net/10191/8247

Compound scattering matrix of targets aligned in the range direction 査読

K Kitayama, Y Yamaguchi, J Yang, H Yamada

IEICE TRANSACTIONS ON COMMUNICATIONS E84B ( 1 ) 81 - 88 2001年1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

The Sinclair scattering matrix is defined in a fixed radar range. If a radar target extends in the range direction, the reflected signal or the compound scattering matrix will undergo interaction of multiple reflections. Since scattering matrix is subject to target parameters such as shape, size, orientation, material, and radar parameters as frequency, polarization, and incidence angle, it is difficult to specify a representative scattering matrix of a general target. Therefore we choose the simplest target, wire, and its scattering matrix to examine the effect of targets aligned in the range direction with respect to the compound scattering matrix. First, we present a simple formula for the compound scattering matrix of wires with the phase difference due to spacing. Then, we employed the FDTD method to examine the scattering phenomena, changing the spacing in the range direction. The FDTD result reveals that two wires can become sphere (plate) and dihedral comet reflector (diplane) component generators: and that four wires can become a good helix component generator. These phenomena are verified with a laboratory measurement. From the result. the target decomposition should be carefully carried out in terms of range. If a range resolution of a radar is not high enough, the scattering matrix of the desired target may be affected by the targets behind.

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時空間MUSIC法におけるパラメータ推定誤差について査読

原六蔵, 山田寛喜, 山口芳雄

電子情報通信学会論文誌B-II J84-B ( 1 ) 137 - 141 2001年1月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：電子情報通信学会

MUSIC法，ESPRIT法などが適用されている電波伝搬の時空間推定では，入射波の相関の有無により，その特性が大きく変化する．本論文では，2次元MUSIC法を例にあげ，入射波がコヒーレント，インコヒーレントな場合の時空間推定誤差特性と信号相関抑圧特性との関連について示した．

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その他リンク： http://hdl.handle.net/10191/8228

Polarimetric SAR interferometry for forest canopy analysis by using the super-resolution method 査読

H Yamada, Y Yamaguchi, E Rodriguez, Y Kim, WM Boerner

IGARSS 2001: SCANNING THE PRESENT AND RESOLVING THE FUTURE, VOLS 1-7, PROCEEDINGS ( CDROM ) 1101 - 1103 2001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

In this paper, we propose an polarimetric SAR interferometry technique for interferometric phase extraction of each local scatterer of the forest region. The proposed method formulated for local scattering center extraction is based on the ESPRIT algorithm which is known for high-resolution capability of closely located incidences, The method shows high-resolution performance when local scattered waves are uncorrelated and have different polarization characteristics. Using the method, the number of dominant local scattered waves and their interferometric phases in each image patch can be estimated directly. Validity of the algorithm is demonstrated by using examples derived from SIR-C data.

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Polarimetric classification of trees 査読

Y Yamaguchi, M Murase, H Yamada, J Yang

2001 CIE INTERNATIONAL CONFERENCE ON RADAR PROCEEDINGS 440 - 443 2001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

Since scattering matrix acquisition capability will be equipped with space-borne radar systems such as ALOS PALSAR to be launched in 2003, "Radar Polarimetry" is now indispensable tool for monitoring the earth cover. The advantage of using vector nature of electromagnetic wave is the information on the amplitude, phase and their relations pertaining to target. In this paper, we tried to retrieve useful index for classifying broad leaf trees and conifer (needle like leaf) tree based on the scattering characteristics of tree canopies. The index is used polarimetric correlation coefficient derived by the elements of Sinclair scattering matrix. It is shown that correlation coefficient defined in the circular polarization basis serves to distinguish conifer tree and broadleaf tree.

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