北极地区海冰既受全球气候变化的影响,同时也影响着全球气候的变化,因此,北极地区已成为研究全球气候变化的热点区域之一。然而,由于北极地区环境恶劣,传统的实地勘测方法成本高,且难度较大。遥感技术,特别是合成孔径雷达(SAR)和全极化SAR技术的迅速发展,为北极地区海冰信息的提取提供了更加有效的数据获取方法。以TerraSAR-X全极化数据为基础,采用SEATH(separability and thresholds)面向对象影像分析方法,评估各种极化特征用于提取北极地区海冰信息的能力,并通过分类实验对其结果进行验证。研究表明:|VV|, T11和SPAN等极化特征对海冰具有较好的区分度,这将为大范围的北极地区海冰信息提取以及海冰监测卫星的参数设计提供理论基础。
英文摘要:
Arctic sea ice has become a hot topic in the research on globe climate change, because it has been affected by the global climate change and can in turn affect the global climate. The traditional survey methods are seriously limited by the severe climate and environment of Arctic area. The development of remote sensing, especially for the Synthetic Aperture Radar (SAR) and Polarimetric SAR, can yield more effective methods for data acquisition in the study of Arctic sea ice. In this paper, the TerraSAR-X polarimetric data and the SEATH(SEparability and THresholds)object-oriented algorithm have been introduced to evaluate the capability of polarimetric features in the Arctic sea ice classification, and some classification examples are presented to show their performances. The classification results demonstrate that the polarimetric features of |VV|, T11 and SPAN show a better performance in Arctic sea ice extraction. The achievement will provide a theoretical foundation for the classification of large-area Arctic sea ice and the parameter design of sea ice monitoring satellites.