close
1.

論文(リポジトリ)

論文(リポジトリ)
Yang, Jian ; Peng, Ying-Ning ; Yamaguchi, Yoshio ; Yamada, Hiroyoshi ; Boerner, Wolfgang-Martin
出版情報: IEICE transactions on communications — IEICE transactions on communications.  E85-B  pp.565-567,  2002-02.  The Institute of Electronics, Information and Communication Engineers
本文リンク: http://hdl.handle.net/10191/21340
概要: The periodicity of a target scattering matrix is studied when the target is rotated about the sight line of a monostatic radar. Except for the periodicity and invariance of the scattering matrix diag(a, a), it is proved that only helixes have the quasi-invariance, and that only N-targets have the quasi-periodicity, demonstrating that a target with some angle rotation symmetry also has the scattering matrix form diag(a, a). From this result, we conclude that it is impossible to extract the shape characteristics of a complex target from its scattering matrix or its Kennaugh matrix. 続きを見る
2.

論文(リポジトリ)

論文(リポジトリ)
Kitayama, Kenji ; Yamaguchi, Yoshio ; Yang, Jian ; Yamada, Hiroyoshi
出版情報: IEICE transactions on communications — IEICE transactions on communications.  E84-B  pp.81-88,  2001-01.  The Institute of Electronics, Information and Communication Engineers
本文リンク: http://hdl.handle.net/10191/21331
概要: 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. Sinece scattering matrix is subject to target parameters such as shape, size, orientation, material, and redar paramenters 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 compoud scattering matrix. First, we present a simple formula for the compound scttering matrix of wires with the phase difference due to spacing. Then, we employed the FDTD method to exmine the scattering phenomena, changing the spacing in the range direction. The FDTD result reveals that two wires can become sphere (plate) and dihedral corner reflector (diplane) component generators; and that four wires can become a good helix component generator. These phenemena are verified with a laboratory measurement. From the result, the traget 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. 続きを見る
3.

論文(リポジトリ)

論文(リポジトリ)
Yamaguchi, Yoshio
出版情報: Proceedings of the IEEE — Proceedings of the IEEE.  100  pp.2851-2860,  2012-10. 
本文リンク: http://hdl.handle.net/10191/19382
概要: This paper presents scattering power decomposition images of fully polarimetric synthetic aperture radar data for disast er monitoring. Utilization of fully polarimetric data can derive full color images with red–green–blue color-coding, red for the double-bounce power, green for the volume scattering power, and blue for the surface scattering power, for which each color brightness corresponds to the magnitude. Since disaster events cause the changes of each scattering power, it becomes straightforward for everyone to recognize the changes of the color in the polarimetric decomposed images provided time series data sets are made available. After applying the four-component scattering power decomposition to fully polarimetric image data sets acquired with the Advanced Land Observing Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR), several images are presented for natural disaster monitoring of volcanic activity, snow accumulation, landslides and tsunami effects caused by great earthquakes. It is seen in the polarimetric decomposition images that the surface scattering power becomes predominant in most disaster areas compared to those in normal situations. 続きを見る