New method for Polarimetric Synthetic Aperture Radar image analysis aiming at classification and identification of targets

保护健康的地球环境对全人类至关重要。在监测地球环境方面，机载雷达遥感或星载雷达遥感发挥着重要作用。幸运的是，日本宇宙航空研究开发机构于2006年1月24日成功发射了名为“Daichi”的先进陆地观测卫星。这颗卫星是世界上第一颗星载极化SAR。它的全极化数据采集功能一直受到世界各国研究机构的关注。该项目的目的一直是“如何利用极化数据”和“可以获得什么样的信息？”对此，我们开展了极化雷达散射功率分解的研究。研究结果如下：1)可以从极化数据中提取四个独立的信息；2)基于二阶统计量，我们可以构造各种矩阵。然而，基本成分可以认为是四。3)协方差…More矩阵和相干矩阵可以分解为4个子矩阵，它们代表了物理散射特性。这些散射是曲面散射、双反弹散射、体积散射和螺旋散射。这4个散射功率可以从这些矩阵中产生。这种分解技术是之前由美国喷气推进实验室的Durden和Freeman提出的三组分分解方法的自然扩展。在项目过程中开发的分解算法简单，易于实现。4)这四个分量很好地代表了物理散射特性，只需看一看彩色编码的POLSAR图像就能看到散射现象。5)这一结果已经在新泻地区的机载PI-SAR数据中得到了验证。此外，雷达极化的原理以及分解方案和项目结果都在报告中进行了详细的描述，以便学生和/或初学者进入这一重要领域。较少

Preservation of the healthy earth environment is vital for all human beings. For monitoring the earth environment, remote sensing by airborne radar or space borne radar play important role for the purpose. Fortunately, Advanced Land Observing Satellite named "Daichi" was successfully launched by JAXA on Jan.24,2006. This satellite is the first space borne polarimetric SAR in the world. It has been attracting attention among world research institutions because of its fully polarimetric data take function.The purpose of the project has been "how to use the polarimetric data" and "what kind of information can be obtained?" In this regard, we carried out the research on decomposition of scattering power acquired by polarimetric radar. The results are summarized as follows :1)Four independent information can be extracted from polarimetric data2)Based on the second order statistics, we can construct various matrices. However, the essential components can be regarded as four.3)The covariance … More matrix and the coherency matrix can be decomposed into 4 sub-matrices which represent physical scattering nature. These are surface scattering, double bounce scattering, volume scattering, and helix scattering. The 4 scattering powers can be generated from these matrices. This decomposition technique is natural extension of the 3-component decomposition method previously proposed by Durden and Freeman at JPL, USA. The decomposition algorithm developed during the project is simple and easy to implement. Therefore it is quite useful for classification and identification of targets.4)The four components represent physical scattering characteristics very well so that one can see the scattering phenomena just looking into the decomposed color-coded POLSAR image.5)The result has been confirmed by airborne Pi-SAR datasets in Niigata Area.In addition, the principle of radar polarimetry together with the decomposition scheme and the project results are described in detail in a report so that students and/or beginners can join this important field. Less