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1.

論文(リポジトリ)

論文(リポジトリ)
Yang, J. ; Yamaguchi, Y. ; Yamada, H. ; Czyz, Z. H. ; Boerner, W. -M. ; Mott, H. ; Luneburg, E. ; Yamaguchi, Yoshio ; Yamada, Hiroyoshi ; 山口, 芳雄 ; 山田, 寛喜
出版情報: IEEE Transactions on Geoscience and Remote Sensing.  40  pp.305-313,  2002.  IEEE
URL: http://hdl.handle.net/10191/4982
概要: Characteristic polarization state theory is restudied for the symmetric coherent Sinclair scattering matrix case. First, the geometric relations of the characteristic polarization states on the Poincare sphere are derived. Based on these relations, simple formulas are given for all of the characteristic polarization states of this Sinclair matrix in Stokes vector form. From the formulation, it is clear that the CO-POL Nulls are fundamental characteristic polarization states for the symmetric coherent Sinclair scattering matrix case, in that the others can straightforwardly be obtained from the Stokes vectors of the CO-POL Nulls. For further study of the characteristic polarization state and the distribution of the received powers on the Poincare sphere, the authors introduce the concept of the equi-power curve. It is defined as the curve on the Poincare sphere on which the received powers in some defined channel have the same value. They deal with the characteristics of the equi-power curves for various special cases. In addition, they show how the characteristic polarization states are generated by the equi-power curves. It is demonstrated that the characteristic polarization states can usually be regarded as the points of contact of the Poincare sphere and a conicoid representing a power-related quadratic form. This leads to a new method to introduce the characteristic polarization states 続きを見る
2.

論文(リポジトリ)

論文(リポジトリ)
Yamaguchi, Y. ; Yajima, Y. ; Yamada, H. ; Yamaguchi, Yoshio ; Yamada, Hiroyoshi ; 山口, 芳雄 ; 山田, 寛喜
出版情報: IEEE Geoscience and Remote Sensing Letters.  3  pp.292-296,  2006.  IEEE
URL: http://hdl.handle.net/10191/4983
概要: A four-component decomposition scheme of the coherency matrix is presented here for the analysis of polarimetric synthetic aperture radar (SAR) images. The coherency matrix is used to deal with nonreflection symmetric scattering case, which is an extension of covariance matrix approach. The same decomposition results have been obtained. The advantage of this approach is explicit expressions of four scattering powers in terms of scattering matrix elements, which serve the interpretation of polarimetric SAR data quantitatively. 続きを見る
3.

論文(リポジトリ)

論文(リポジトリ)
Yamaguchi, Y. ; Moriyama, T. ; Ishido, M. ; Yamada, H. ; Yamaguchi, Yoshio ; Yamada, Hiroyoshi ; 山口, 芳雄 ; 山田, 寛喜
出版情報: IEEE Transactions on Geoscience and Remote Sensing.  43  pp.1699-1706,  2005.  IEEE
URL: http://hdl.handle.net/10191/4987
概要: A four-component scattering model is proposed to decompose polarimetric synthetic aperture radar (SAR) images. The covariance matrix approach is used to deal with the nonreflection symmetric scattering case. This scheme includes and extends the three-component decomposition method introduced by Freeman and Durden dealing with the reflection symmetry condition that the co-pol and the cross-pol correlations are close to zero. Helix scattering power is added as the fourth component to the three-component scattering model which describes surface, double bounce, and volume scattering. This helix scattering term is added to take account of the co-pol and the cross-pol correlations which generally appear in complex urban area scattering and disappear for a natural distributed scatterer. This term is relevant for describing man-made targets in urban area scattering. In addition, asymmetric volume scattering covariance matrices are introduced in dependence of the relative backscattering magnitude between HH and VV. A modification of probability density function for a cloud of dipole scatterers yields asymmetric covariance matrices. An appropriate choice among the symmetric or asymmetric volume scattering covariance matrices allows us to make a best fit to the measured data. A four-component decomposition algorithm is developed to deal with a general scattering case. The result of this decomposition is demonstrated with L-band Pi-SAR images taken over the city of Niigata, Japan. 続きを見る
4.

論文(リポジトリ)

論文(リポジトリ)
Yang, J. ; Dong, G. ; Peng, Y. ; Yamaguchi, Y. ; Yamada, H. ; Yamaguchi, Yoshio ; Yamada, Hiroyoshi ; 山口, 芳雄 ; 山田, 寛喜
出版情報: IEEE Geoscience and Remote Sensing Letters.  1  pp.171-174,  2004.  IEEE
URL: http://hdl.handle.net/10191/4988
概要: A generalized optimization of polarimetric contrast enhancement (GOPCE) is proposed in this letter. For this problem, it is not only necessary to find the optimal polarization states such that the received power ratio of a desired target and clutter is maximal, but also necessary to find three optimal coefficients such that the ratio of two factors associated with the desired target and clutter is maximal, where both the factors consist of three parameters, i.e., the Cloude entropy and two special similarity parameters. The optimal coefficients of the GOPCE are obtained by solving an eigenvalue problem. Using an example, we demonstrate that the GOPCE can be employed for detecting roads in a forest area by using polarimetric synthetic aperture radar data. 続きを見る
5.

論文(リポジトリ)

論文(リポジトリ)
Yang, J. ; Peng, Y. -N. ; Yamaguchi, Y. ; Yamada, H. ; Yamaguchi, Yoshio ; Yamada, Hiroyoshi ; 山口, 芳雄 ; 山田, 寛喜
出版情報: IEEE Geoscience and Remote Sensing Letters.  3  pp.369-372,  2006.  IEEE
URL: http://hdl.handle.net/10191/4996
概要: For some special case, Huynen's decomposition cannot be used to extract a desired target from an average Kennaugh matrix. In this paper, the authors modify Huynen's method for overcoming its disadvantage, based on a simple transform of a Kennaugh matrix. Using an example, the effectiveness of the modified method is validated. 続きを見る
6.

論文(リポジトリ)

論文(リポジトリ)
Yang, J. ; Yamaguchi, Y. ; Yamada, H. ; Boerner, W. -M. ; Mott, H. ; Peng, Y. -N. ; Yamaguchi, Yoshio ; Yamada, Hiroyoshi ; 山口, 芳雄 ; 山田, 寛喜
出版情報: IEEE Transactions on Geoscience and Remote Sensing.  39  pp.330-338,  2001.  IEEE
URL: http://hdl.handle.net/10191/4997
概要: 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 続きを見る
7.

論文(リポジトリ)

論文(リポジトリ)
Yamaguchi, Y. ; Kimura, K. ; Kakizaki, S. ; Yamada, H. ; Yamaguchi, Yoshio ; Yamada, Hiroyoshi ; 山口, 芳雄 ; 山田, 寛喜
出版情報: IGARSS '02. 2002 IEEE Geoscience and Remote Sensing Symposium, 2002..  1  pp.381-383,  2002.  IEEE
URL: http://hdl.handle.net/10191/5015
概要: The ALOS-PALSAR is the first L-band space-borne SAR in the world equipped with a fully polarimetric data taking function. For the data utilization purpose, the authors have examined the polarimetric performance (scattering matrix and resultant images) over the Toyano area, Niigata City, Japan, using the airborne Pi-SAR radar. Since the resolution will be 20 m by 20 m on the ground surface by PALSAR, the Pi-SAR data (3 m by 3 m) are ensembled to be an equivalent size for ALOS-PALSAR image simulation. The polarimetric characteristics of terrain including paddy-fields, grass-fields, residential areas, etc., were examined to show the difference in the right-left polarization handedness basis and coherency vector, three-component scattering model, and polarimetric entropy. 続きを見る
8.

論文(リポジトリ)

論文(リポジトリ)
Yamada, H. ; Yamaguchi, Y. ; Boerner, W. -M. ; Yamada, Hiroyoshi ; Yamaguchi, Yoshio ; 山田, 寛喜 ; 山口, 芳雄
出版情報: IGARSS '03. Proceedings. 2003 IEEE International Geoscience and Remote Sensing Symposium, 2003..  3  pp.1426-1428,  2003.  IEEE
URL: http://hdl.handle.net/10191/5018
概要: This paper present a new forest height feature extraction technique for single baseline polarimetric and interferometric SAR data. The authors have proposed polarimetric SAR interferometry based on the ESPRIT algorithm. However, the algorithm assumes that there exist dominant polarized components in both the ground and canopy. Hence, estimated interferometric phase of local scattering centers may be slightly biased when forest components are highly depolarized. In this report, we examine effect of depolarized components of forest in ESPRIT-based polarimetric SAR interferometry. Numerical examples show that the effective scenario for the algorithm. Also, we present an alternative derivation o f t he E SPRI T-type a lgorithm w hich h elps u s understand how the ESPRIT algorithm works for depolarized components. Experimental results by using E-SAR data are also provided to show the performance of the ESPRIT estimation. 続きを見る
9.

論文(リポジトリ)

論文(リポジトリ)
Yamada, H. ; Sato, K. ; Yamaguchi, Y. ; Boerner, W. -M. ; Yamada, Hiroyoshi ; Yamaguchi, Yoshio ; 山田, 寛喜 ; 山口, 芳雄
出版情報: IGARSS '02. 2002 IEEE International Geoscience and Remote Sensing Symposium, 2002..  2  pp.829-831,  2002.  IEEE
URL: http://hdl.handle.net/10191/5019
概要: Polarimetric SAR interferometry has been widely studied for forest observations. The technique utilizes polarization state difference among local scattering centers of the forest to decompose them. Using the method, we can estimate precise forest parameters. We proposed an alternative method based on the ESPRIT algorithm for the estimation. The method can detect as many as 3 local scatterers with fully polarimetric data, and can extract interferometric phase of each local scatterer. In this paper, we verify the availability of the method in 2- and 3-local-scatterer model for forest estimation, and show that forest analysis with 3-local-scatterer improve height estimation accuracy. SIR-C/X-SAR data were used for these verifications. In addition, experimental results of restricted dual-polarization data are also provided to show availability of the method. 続きを見る
10.

論文(リポジトリ)

論文(リポジトリ)
Yamaguchi, Y. ; Kimura, K. ; Yamada, H. ; Uratsuka, S. ; Boerner, W. -M. ; Yamaguchi, Yoshio ; Yamada, Hiroyoshi ; 山口, 芳雄 ; 山田, 寛喜
出版情報: IGARSS '02. 2002 IEEE International Geoscience and Remote Sensing Symposium, 2002..  1  pp.423-425,  2002.  IEEE
URL: http://hdl.handle.net/10191/5020
概要: Pacific Rim Campaign has been successfully carried out in 2000. The well known AIRSAR system by JPL flew over Niigata Area, Japan, on Oct. 2, 2000, which brought us the L-band fully polarimetric data set. On the other hand, Pi-SAR, developed by CRL and NASDA, Japan, simultaneously (2 hours in advance) flew the same path taking the same area data in the L-band. It became possible for us to carry out comparative analyses using the same area data. Since the resolution and incidence angle of each SAR are different, we examined the difference in the two POL-SAR images using correlation coefficient in the Right-Left Circular (RL) polarization basis, polarimetric entropy, and three component scattering power ratio. 続きを見る