基于多源遥感影像特征检索的东南极冰流速变化监测研究

Ice dynamic model indicates how the ice drifts from antarctic inland to the ocean and how ice mass evolves. Monitoring Antarctic ice stream dynamics with ice dynamic models is of considerably value to many environmental researches, including ice shelf disintegration, ice mass balance and further, global climate change and environmental change, all of which are important scientific issues at present. This project studies the ice streams dynamics of East Antarctic outlet glaciers and its changes by developing a novel research framework of estimating ice flow velocity based on multi-source image feature retrieval. The framework consists of four steps: image segmentation, feature description, feature retrieval and ice flow velocity monitoring. To be specific, the main research contents are as follows,.(a)developing a land-cover feature based region segmentation method by using adaptive scale selection, and thereby providing highly reliable regional information for Antarctic ice feature description. .(b)building a resolution-independent feature description model to describe features of both regions and salient points on multi-source images..(c)realizing multi-source image feature retrieval and developing region-based ice flow velocity estimation method, in order to study the ice stream dynamics and its seasonal and inter-annual changes of East Antarctic outlet glaciers, followed by analyzing ice shelf disintegration..This project will develop fast and automatic ice flow velocity estimation methods and the outcomes will provide valuable information to the research of Antarctic ice streams dynamics and its influences on global changes.

监测南极冰流速，对研究南极冰架崩解、物质平衡及全球气候变化和环境变迁等具有重大意义。本项目拟以"影像分割－特征描述－特征检索－冰流速变化监测"为主线，发展基于多源影像特征检索的东南极冰盖边缘区域冰流速自动估算理论与方法，监测该区域的冰流速并分析其变化，主要研究内容包括：(1)发展一种基于地表特征的自适应尺度选择的区域分割方法，为南极冰面特征描述提供高准确度的区域信息；(2)建立分辨率无关的特征描述模型，实现多源影像区域和区域内显著特征点的特征描述；(3)实现多源影像特征检索，发展基于区域的冰流速估算方法，估算东南极冰盖边缘区域冰流速并分析其年际、季节变化，结合冰流速进一步分析冰架前缘崩解状态。本项目研究成果将为快速、自动估算极地冰流速提供有力的技术支撑，为研究南极冰盖的动态变化及其对全球变化的贡献提供区域性的定量结果，具有重要的理论价值和实际意义。

监测两极冰流速，对于研究两极冰架崩解、冰盖物质平衡及其对全球气候和环境的影响等具有重大意义，是分析冰盖变化的关键问题。本项目拟以“旋转不变的特征提取－冰流速估算－冰流速变化监测”为主线，发展快速、自动、高效、稳健的南极地区冰流速估算理论与方法，以极记录冰川为例并完成对该区域冰流速的变化监测和分析。主要研究内容包括以下几个方面：(1) 针对冰川在运动过程中发生的旋转偏移的现象，发展一种基于旋转不变特征的冰面特征提取方法结合光谱特征完成冰流速估算，结果不仅获得更多重要区域的冰流速而且获得更高精度；(2)以极记录冰川为例，完成该冰川2004年至2013年间的年际冰川流速图，并对其流速分布特点进行分析；(3)考虑到表面温度变化而引起的融水可能到达冰川底部而加速冰川运动，发展一种高精度的冰雪表面温度反演方法，产品精度较NASA标准产品精度高0.5K；(4)以Amery冰架、Ross冰架和Ronne冰架为例，分析2000年至2014年夏季冰架表面温度变化，并结合全南极冰流速图分析表面温度和流速的相关性。