摘要
内尔斯海峡是北极海冰输出的重要通道之一,从海峡流出的海冰对巴芬湾、拉布拉多海深层水的形成以及北极海冰物质平衡具有重要影响。由于海峡入口狭窄和海冰密集度较低,现有海冰运动反演算法较难从卫星影像上获取有效的海冰运动信息,从而限制了该区域海冰运动信息的提取。本研究提出了一种基于浮冰形状特征的海冰运动提取算法,该算法主要包括影像分割、浮冰提取和浮冰匹配3个步骤。使用该算法从2019年2月20-27日逐日哨兵1号影像中提取了内尔斯海峡的海冰运动信息,并结合人工制作的验证数据评估了该算法在浮冰提取和匹配过程的精度。结果显示该算法提取的浮冰形状参数平均误差为4.3%~8.48%、浮冰运动矢量的总体正确率为84%、浮冰质心与运动速度的均方根误差分别为0.171km和6.313cm·s^(–1)。对比SIFT,ORB和AKAZE三种基于特征追踪的海冰运动反演算法,该算法结果中海冰运动覆盖面积增加了27.7%,精度提高约39%。该算法不仅有效地提取了内尔斯海峡海冰运动信息,而且可为其他区域(如海冰边缘区)的海冰运动信息提取提供参考。
The Nares Strait is one of the most important passages for sea ice outflow from the Arctic Ocean.It plays a crucial role in the formation of deep water in the Baffin Bay and Labrador Sea and in the Arctic sea ice mass balance.Because of the narrow entrance and low sea ice concentration,it is difficult to retrieve valid sea ice motion information from satellite imagery using existing sea ice motion tracking algorithms.Therefore,there are limited sea ice motion data for this region.In this study,a sea ice motion retrieval algorithm based on ice floe shape features is proposed.It consists of three main steps:image segmentation,ice floe extraction and ice floe matching.Sea ice motion data in the Nares Strait from 20 February to 27 February 2019 were retrieved using the proposed algorithm,and were compared with manually produced validation data to evaluate the accuracy of the ice floe extraction and matching steps.Results show that the mean error of the ice floe shape features ranges from 4.3%to 8.48%,the overall accuracy of the ice floe motion vectors retrieved by the algorithm is 84%,and the root mean square error of the matched centroid and velocity is 0.171 km and 6.313 cm·s^(–1),respectively.Compared with existing feature tracking algorithms,including SIFT,ORB,and AKAZE,sea ice motion coverage and accuracy derived from the proposed algorithm are higher by 27.7%and 39%,respectively.The proposed algorithm is not only an effective way to retrieve sea ice motion data for the Nares Strait,but provides some reference for sea ice motion retrieval in other regions(e.g.,marginal ice zone).
作者
杨帆
刘婷婷
雷瑞波
YANG Fan;LIU Tingting;LEI Ruibo(Chinese Antarctic Center of Surveying and Mapping,Wuhan University,Wuhan 430072,China;Key Laboratory of Polar Environment Monitoring and Public Governance(Wuhan University),Ministry of Education,Wuhan 430072,China;Key Laboratory of Polar Science,MNR,Polar Research Institute of China,Shanghai 200136,China)
出处
《极地研究》
CAS
CSCD
北大核心
2024年第2期169-182,共14页
Chinese Journal of Polar Research
基金
国家重点研发计划(2021YFC2803301)
自然资源部极地科学重点实验室开放基金(KP202004)
中央高校基本科研业务费专项资金(2042024kf0037)
中央高校自主科研项目(2042022dx0001)资助。
关键词
内尔斯海峡
海冰运动
哨兵1号
影像分割
浮冰匹配
Nares Strait
sea ice motion
Sentinel-1
image segmentation
ice floe matching
