研究者詳細 - 山田　寛喜

論文 - 山田　寛喜

分割表示 893 件中 161 - 180 件目／全件表示 >>

Fundamental Study on Scattering Characteristics from Man-made Objects Using the FDTD Polarimetric Scattering Analysis 査読

R.Sato, Y.Yamauchi, H.Yamada, Sang-Eun Park

Electronic Proc. of Asia-Pacific Radio Science Conference (AP-RASC’13) 2013年9月

マルチパス環境における動きのある人物の屋内位置推定に関する基礎検討査読

佐藤耕平, 山田寛喜, 山口芳雄

電子情報通信学会技術研究報告 AP2013-81 ( 9 ) 7 - 12 2013年9月

L-バンドPOLSAR画像分解における様々な散乱モデル分解法の特性評価査読

佐藤大輔, 渡邉卓磨, 山田寛喜, パクサンウン・ツィイー, 山口芳雄

電子情報通信学会技術研究報告 SANE2013-50 ( 8 ) 31 - 36 2013年8月

自由走査式測定システムによる電磁波散乱分布の可視化の検討査読

山田敏弘, 山田寛喜, 山口芳雄

電子情報通信学会技術研究報告 SANE2013-47 ( 8 ) 11 - 16 2013年8月

偏波相関係数を用いた水域と自然領域の検出に関する検討査読

渡辺祐太, 山本和朋, Park Sang-Eun, 山口芳雄, 山田寛喜

電子情報通信学会技術研究報告 SANE2013-51 ( 8 ) 43 - 47 2013年8月

DOA Estimation Error Reduction of Nested Array Using N-th Root of Correlation Matrix 査読

Satoshi Shirai, Hiroyoshi Yamada, Yoshio Yamaguchi

Proc. 2013 IEEE AP-S Symposium and USNC/URSI Meeting 2013年7月

相関波到来時におけるNested Arrayを用いたDOA推定に関する検討査読

白井智士, 山田寛喜, 山口芳雄

電気学会計測研究会 IM-13-017 ( 3 ) 11 - 16 2013年3月

非RS偏波散乱特性を利用した人工物識別アルゴリズム査読

佐野華枝, 佐藤亮一, 山口芳雄, 山田寛喜

電子情報通信学会総合大会 ( C-1-27 ) 2013年3月

Khatri-Rao積拡張アレー処理を用いた海洋レーダのドップラ周波数推定特性について査読

小沢直輝, 山田寛喜, 山口芳雄, 平野圭蔵, 伊藤浩之

電子情報通信学会総合大会 ( B-2-33 ) 2013年3月

行列累乗根を用いたKhatri-Rao積拡張アレーによるDOA推定誤差軽減に関する検討査読

白井智士, 山田寛喜, 山口芳雄

電子情報通信学会総合大会 ( B-1-201 ) 2013年3月

MIMOセキュリティセンサを用いた屋内侵入検出システムの検出性能に関する検討査読

小川研, 山田寛喜, 山口芳雄

電子情報通信学会技術研究報告 SANE2012-154 ( 2 ) 31 - 36 2013年2月

Khatri-Rao積拡張アレー処理による海洋レーダ分解能特性改善に関する検討査読

小沢直輝, 山田寛喜, 山口芳雄, 平野圭蔵, 伊藤浩之

電子情報通信学会技術研究報告 SANE2012-136 ( 1 ) 55 - 60 2013年1月

Stable Parameter Estimation of Compound Wishart Distribution for Polarimetric SAR Data Modeling 査読

Yi Cui, Hiroyoshi Yamada, Yoshio Yamaguchi

2013 PROCEEDINGS OF THE INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION (ISAP), VOLS 1 AND 2 2013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 investigates the parameter estimation of compound Wishart distribution for statistical modeling of polarimetric synthetic aperture radar data. We show that the recently proposed method of matrix log-cumulant may lead to non-invertible equations and cause unstable performances. In order to overcome such difficulty, we proposed a Bayesian-based method to re-estimate the log-cumulants. Simulation experiment demonstrates that the proposed algorithm provides both improved and stabler results. Finally, we present an application of the new method for texture analysis of the Germany F-SAR polarimetric data.

Web of Science

researchmap

Experimental Study on Statistical Characteristic of MIMO Sensor for Event Detection 査読

Shinji Itabashi, Hiroyoshi Yamada, Kentaro Nishimori, Yoshio Yamaguchi

2013 PROCEEDINGS OF THE INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION (ISAP), VOLS 1 AND 2 2013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

Recently, researches on radio wave security sensors by using array antenna or MIMO(Multiple-Input Multiple Output) system have been attracting attention. These sensors utilize the property that MIMO channel matrix is sensitive to the propagation environment change in indoor multipath environment. Now the property is used for event detection, such as intrusion, by calculating correlation of MIMO channel matrices. Fundamental study has been performed, however, statistical property, or quantitative detection performance analysis, of the sensor was still remain to be clarified. So, our objective is to derive a probability density function (PDF) of the correlation coefficient and to demonstrate them experimentally. The PDF is a key function to derive detection rate and so on. In the conventional MIMO sensor, correlation coefficient of the channel matrix between with and without an event is used as a measure of events. Therefore, in this report we will derive the PDF of the channel correlation used in the conventional MIMO sensor theoretically and also show the validity by experimental results.

Web of Science

researchmap

Angular resolution improvement of ocean surface current radar based on the Khatri-Rao product array processing 査読

Hiroyoshi Yamada, Naoki Ozawa, Yoshio Yamaguchi, Keizo Hirano, Hiroyuki Ito

IEICE Transactions on Communications E96-B ( 10 ) 2469 - 2474 2013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：Institute of Electronics, Information and Communication, Engineers, IEICE

Ocean surface current radar is a Doppler radar to observe oceanographic information using the Bragg scattering resonance mechanism. In this paper, we consider angular resolution improvement of the radar. The radar employs an antenna array with FMICW operation, then it can resolve angular distribution by Digital Beam Forming (DBF) and distance by Fourier transform of the beat signal obtained by the FMICW radar. In order to obtain sufficient angular resolution, large array length or aperture with increasing the number of elements is needed, that is often difficult to realize in the HF/VHF ocean surface current radar. In this paper we propose to apply the Khatri-Rao (KR) product array processing to the radar. To verify effectiveness of the KR product array processing in angular resolution enhancement for the ocean surface current radar, we apply the KR product array to actual experimental data set of the radar, and show that the method is available to angular resolution enhancement and Doppler spectrum improvement. Copyright © 2013 The Institute of Electronics, Information and Communication Engineers.

DOI： 10.1587/transcom.E96.B.2469

Scopus

researchmap

Comparison of Model-Based Polarimetric Decomposition Algorithms 査読

Daisuke Sato, Takuma Watanabe, Hiroyoshi Yamada, Yoshio Yamaguchi

CONFERENCE PROCEEDINGS OF 2013 ASIA-PACIFIC CONFERENCE ON SYNTHETIC APERTURE RADAR (APSAR) 346 - 349 2013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

Recently, many model-based decomposition algorithms, which are based on several scattering models, have been proposed to extract physical parameters of the Earth's surface [1]-[4]. Those algorithms decompose the received power into several scattering components, and some assumptions are necessary to find the scattering contribution. By the assumption( s) and scattering models in a used algorithm, decomposed scattering power of each component becomes often different with each other. Therefore, it is difficult to judge which algorithm is the best for a certain observation area. It can be useful to compare the algorithms and to clarify which one is suitable to detect a particular scattering mechanism. As a first step of the research, we compared several model-based polarimetric decomposition algorithms qualitatively from a viewpoint of "a visual difference in decomposition images", "negative power", and "ratio of scattering power". In this paper, forested and urban area are selected for discussion.

Web of Science

researchmap

Comparison of Model-Based Four-Component Scattering Power Decompositions 査読

Yoshio Yamaguchi, Gulab Singh, Cui Yi, Sang Eun Park, Hiroyoshi Yamada, Ryoichi Sato

CONFERENCE PROCEEDINGS OF 2013 ASIA-PACIFIC CONFERENCE ON SYNTHETIC APERTURE RADAR (APSAR) 92 - 95 2013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 reviews the model-based scattering power decomposition methods of fully polarimetric SAR data. Starting from Freeman & Durden 3-component decomposition, comparison of 4-component decompositions are given in terms of available information included in the coherency matrix. The final general 4-component decomposition method with unitary transformation (G4U) employs 100% polarimetric information.

Web of Science

researchmap

EXPERIMENTAL STUDY ON RADAR BACKSCATTERER FROM A SIMPLIFIED FOREST MODEL 査読

Takuma Watanabe, Hiroyoshi Yamada, Motofumi Arii, Ryoichi Sato, Sang-Eun Park, Yoshio Yamaguchi

CONFERENCE PROCEEDINGS OF 2013 ASIA-PACIFIC CONFERENCE ON SYNTHETIC APERTURE RADAR (APSAR) 561 - + 2013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

Polarimetric radar has a potential ability to retrieve forest parameters such as the moisture content and the biomass. Accurate retrieval of those parameters is the key to understand forest ecosystem and to prevent global climate change. For those purposes, this research aims to establish a quantitative approach to the forest parameter retrieval using polarimetric radar. To achieve this, we need a scattering model which describes scattering from forested terrain. The scattering mechanism has been extensively investigated, and several scattering models have been proposed. Although those models are validated with a field experiment, difficulties arise because those models require many input parameters which are difficult to measure accurately over widespread area. Therefore, a relatively simple scattering model is necessary, and carefully controlled experiment is essential to validate the model. In this research, we employ the discrete scatterer model (DSM) described in [1] as the forest scattering model. Using this model, we pointed out that fully polarimetric observation has the potential ability to retrieve the moisture content of forested terrain [2]. This paper aims to prove this theoretical result through an indoor fully polarimetric measurement.

Web of Science

researchmap

Simplified Algorithm For Detecting Oriented Man-made Objects Using Correlation Coefficients in Circular Polarization Basis 査読

Ryoichi Sato, Hanae Sano, Yoshio Yamaguchi, Hiroyoshi Yamada, Sang-Eun Park

CONFERENCE PROCEEDINGS OF 2013 ASIA-PACIFIC CONFERENCE ON SYNTHETIC APERTURE RADAR (APSAR) 556 - 558 2013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 proposes a simple algorithm to precisely detect man-made objects with any alignment to radar illumination direction. Here, a couple of polarimetric indices, i.e. the co-pol. correlation coefficient in LR circular polarization basis, and its normalized one are utilized in the algorithm, since the former is emphasized in reflection symmetry (RS) as normally aligned man-made objects area, whereas the latter is enhanced in Non-RS as obliquely aligned man-made objects area. The appropriate thresholds for switching the polarimetric indices are determined by considering the result of polarimetric scattering analysis for simplified man-made objects model. The Finite-Difference Time-Domain (FDTD) method is utilized for the analysis. It is finally confirmed from the result of the PolSAR image analysis that the proposed algorithm is very effective for detecting the man-made objects not only normally but also obliquely alignment to the radar illumination direction.

Web of Science

researchmap

Comparison of Speckle Filtering Methods for POLSAR Analysis of Earthquake Damaged Areas 査読

Kazutomo Yamamoto, Yoshio Yamaguchi, Sang-Eun Park, Yi Cui, Hiroyoshi Yamada

CONFERENCE PROCEEDINGS OF 2013 ASIA-PACIFIC CONFERENCE ON SYNTHETIC APERTURE RADAR (APSAR) 358 - 360 2013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

Speckle noise makes the synthetic aperture radar (SAR) image interpretation difficult and reduces the accuracy of the rapid disaster assessment. This paper introduces the influence of speckle filtering methods on the polarimetric SAR data interpretation of damages. Four types of speckle filtering methods, such as boxcar filter, refined Lee filter, Lee sigma filter, and sequential filter, are investigated to determine the best filtering options for detection of damaged areas. As a result, Lee sigma filter exhibits the best performance in the analysis of the damaged areas. The sequential filtering approach also shows a good performance, which is comparable with that of Lee sigma filter, with minimum computational cost.

Web of Science

researchmap

　前のページ - 次のページ　

<山田 寛喜>

論文 - 山田 寛喜

<山田　寛喜>

論文 - 山田　寛喜