面向对象的高分辨率SAR图像处理及应用

The processing and applications of high resolution SAR images with object-based image analysis

目的随着合成孔径雷达(SAR)技术和分辨率的不断提高,越来越多的空间细节呈现在高分辨率SAR影像上。与此同时,SAR图像的数据量越来越大,人们对其应用需求也越来越高,这使得传统的基于像素的SAR处理方法不再适用。面向对象分析技术以像元集合——"对象"为分析单元,为高分辨率遥感图像处理提供了有效的思路,并日渐成为遥感、摄影测量以及GIS等领域所关注的对象和研究热点之一。目前该技术在光学遥感中已经得到了广泛的应用,但在SAR图像处理中的应用还处于起步阶段。方法本文在简要阐述面向对象分析技术起源和特点的基础上,对SAR图像面向对象技术中常用的多尺度分割算法进行了分类分析,接着对面向对象技术在SAR遥感的应用方向进行全面介绍,最后对面向对象技术在SAR上的应用进行了总结与展望。结果面向对象分析技术在SAR图像处理中的应用主要分为以下五个方面:地物分类、城市信息提取、变化检测、海洋应用、森林应用。结论面向对象分析技术在解决高分辨率SAR图像尺度效应、抑制噪声等方面有着重要作用。目前,国外学者在基于SAR的面向对象分析技术研究上已经取得了一定的进展,但总体上该技术仍面临诸多问题,需要进一步的研究和完善。

Objective With the continuous development of technology and resolution on synthetic aperture radar （SAR） , thinner spatial features can be observed from the high resolution of newly available SAR images. Due to the larger data vol- ume and higher application requirements, the traditional pixel-based methods have many limitations in high-resolution SAR processing. Object-based image analysis （OBIA） provides a new idea for high resolution remote sensing image analysis based on the pixel set- ＂object＂, which is becoming one of the hot spots of remote sensing, photogrammetry and GIS. Currently, the technique has been widely used in optical remote sensing. However, the application in SAR image process- ing is still in its early stage. The objective of this review paper is to provide a comprehensive overview and sound summary of all of the work undertaken. Method In this paper, after briefly introducing the origin and characteristic of object-based image analysis technique, the muti-scale segmentation methods commonly used in SAR image, are introduced. Then theapplications of object-based image analysis in high resolution SAR images processing are presented. Finally, the conclu- sions are drawn and the outlook of the applications of object-oriented technology in SAR image is given. Result The object- based image analysis has been used in some SAR applications successfully, such as image classification, information extraction of urban area, change detection, the monitoring on ocean and forest. Conclusion The object-based image analy- sis plays an important role in solving the scale effect and speckle reduction of high-resolution SAR images. Recently, while some excellent studies have been performed in the applications of SAR Images with object-based image analysis, many challenges remain and much work still needs to be investigated.