| 摘要: |
| 中国南海是内波频发海域,卫星遥感在内波参数特征的统计分析中得到了广泛应用,但是卫星轨道的重复访问时间长,不能连续观测内波参数的变化特征。X波段海洋雷达具有高时间和空间分辨率,可以长期连续观测内波的变化,本文提出了利用X波段海洋雷达图像提取内波参数的方法,并利用连续观测的数据研究了各参数的分布特征。首先,对雷达图像进行预处理,包括平均处理及斜坡校正两步;利用二维快速傅里叶变换确定内波的传播方向,进而根据该方向上的径向廓线确定内波的相速度大小、波长及周期。最后,利用在南海石油平台上观测的X波段雷达图像对内波各参数进行提取和统计分析,结果表明,研究区域内波的传播方向多为西北向及西向传播,相速度多为0.6~0.8 m/s,波长一般为400~600 m,周期大部分不超过1000 s。 |
| 关键词: 海洋内波 南海西北部 X波段海洋雷达 参数统计 |
| DOI：10.11759/hykx2021109002 |
| 分类号:P733 |
| 基金项目:国家自然科学基金国际合作项目(41620104003);国家自然科学基金重大仪器设备研制项目(42027805);江苏省海洋科技创新专项项目(HY2018-12);国家自然科学基金青年基金(41506199);江苏省自然科学基金青年基金(BK20150905) |
|
| Study of the characteristics of internal wave parameters in the northwestern South China Sea based on X-band marine radar |
|
WEN Jing-han1, HE Yi-jun1,2, CHEN Zhong-biao1
|
|
1.College of Marine Sciences, Nanjing University of Information Science & Technology, Nanjing 210044, China;2.Key Laboratory of Space Ocean Remote Sensing and Applications, National Satellite Ocean Application Service, Beijing 100081, China
|
| Abstract: |
| Internal waves (IWs) frequently occur in the South China Sea (SCS), and satellite remote sensing images have been widely used to analyze the characteristics of IW parameters. However, the repeated access time of the satellite orbit is long; thus, the characteristics of IW parameters cannot be continuously observed. X-band marine radar has high temporal and spatial resolutions, which can be used to observe the change of IWs continuously. In this study, a method for determining IW parameters from X-band marine radar images is proposed, and the characteristics of each parameter are investigated using continuous observation data. Firstly, X-band marine radar images are preprocessed by averaging and ramp correction. Secondly, the propagation directions of IWs are determined by the two-dimensional fast Fourier transform, and the parameters of IWs are determined by the radial profile in this direction, such as the phase velocity, wavelength, and period. Finally, the X-band radar images observed on the SCS oil platform are used to extract and statistically analyze the parameters of IWs. The results show that the propagation directions of IWs in the study area are mostly northwest and west, the phase velocities are mostly 0.6–0.8 m/s, the wavelengths are generally 400–600 m, and the periods are mostly less than 1, 000 s. |
| Key words: internal wave the northwestern South China Sea X-band marine radar parametric statistics |
