摘要
海洋内波在海洋活动中扮演重要角色。海洋内波研究对我国海洋科学的理论研究、海洋资源的保护、开发和利用以及海洋军事等方面均具有重要意义。为了及时发现海洋内波的发生地点以及对海洋内波参数进行定量分析,本研究基于合成孔径雷达(syntheticapertureradar,SAR)影像中内波明暗条纹的边界特性,提出了一种集成的海洋内波检测算法:主要运用列分离邻域处理和Canny算子边缘检测算法对条纹进行检测,并利用海洋内波的轮廓长度、面积比值及传播方向三个特征对条纹进行筛选,并将该算法应用于南海发生的多起海洋内波,以验证算法的鲁棒性和适用性。研究结果表明,该算法能够较好地识别出海洋内波的明暗条纹,不仅能够除去非内波条纹的轮廓,而且能够去除一些细小且不明显的内波条纹轮廓。利用余弦函数逐像素地对识别后的条纹进行拟合,然后根据拟合结果找出明暗条纹所在位置以及相邻明暗条纹之间的间距,从而判定出内波发生的位置。
Ocean internal waves play an important role in the activities of ocean.The study of ocean internal waves is of great significance to theoretical research of marine science,the protection,development and utilization of marine resources,and maritime military in China.In order to find the location of ocean internal waves in time and quantitatively analyze the parameters of ocean internal waves,an integrated detection algorithm is proposed on the basis of the boundary characteristics of light and dark stripes of ocean internal waves in Synthetic Aperture Radar(SAR)images.The stripes are detected through the process of column separation neighborhood and the edge detection algorithm of Canny operator,and selected by the use of the three features of ocean internal waves including contour length,area ratio,and propagation direction.The algorithm is applied to several internal waves in the South China Sea to verify its robustness and applicability.The results show that the proposed algorithm can effectively identify the light and dark stripes of ocean internal waves,and can remove not only the contour of the non-internal wave stripes but also the small and unobvious stripes contours of internal waves.The detected stripes are fitted pixel by pixel with cosine function,and the locations of the light and dark stripes and the distance between the light and dark stripes are found based on the fitted results.The location of the internal waves is thus determined.
作者
郑应刚
张洪生
李晓恋
张周昊
ZHENG Yinggang;ZHANG Hongsheng;LI Xiaolian;ZHANG Zhouhao(College of Ocean Science and Engineering,Shanghai Maritime University,Shanghai 201306,China)
出处
《热带海洋学报》
CAS
CSCD
北大核心
2020年第6期41-56,共16页
Journal of Tropical Oceanography
基金
国家自然科学基金项目(51679132、51079082)
上海市地方高校基地能力建设项目(17040501600)。
关键词
海洋内波
SAR
CANNY算子
轮廓分类
面积比
方向特性
余弦拟合
ocean internal waves
SAR
Canny operator
contour classification
area ratio
directional characteristic
cosine fitting