2022-10-03T00:42:54Zhttps://niigata-u.repo.nii.ac.jp/oaioai:niigata-u.repo.nii.ac.jp:000017322021-03-01T09:00:44ZDevelopment of target null theoryYang, J.Yamaguchi, Y.Yamada, H.Boerner, W. -M.Mott, H.Peng, Y. -N.©(2001) IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained the IEEE.Polarizationradar polarimetryscattering matrixtarget nullIn 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 presentedIEEE2001-02engjournal articlehttp://hdl.handle.net/10191/4997https://niigata-u.repo.nii.ac.jp/records/1732info:doi/10.1109/36.905241AA0023148301962892IEEE transactions on geoscience and remote sensingIEEE transactions on geoscience and remote sensing392330338https://niigata-u.repo.nii.ac.jp/record/1732/files/(Yamaguchi deve of target)00905241.pdfapplication/pdf172.5 kB2019-07-29