Journal of Tropical Oceanography ›› 2020, Vol. 39 ›› Issue (6): 41-56.doi: 10.11978/2019120CSTR: 32234.14.2019120

• Marine Hydrology • Previous Articles     Next Articles

Detection algorithm of internal waves in the South China Sea based on boundary characteristics of remote sensing image

ZHENG Yinggang(), ZHANG Hongsheng(), LI Xiaolian, ZHANG Zhouhao   

  1. College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai 201306, China
  • Received:2019-11-23 Revised:2020-01-22 Online:2020-10-10 Published:2020-04-09
  • Contact: ZHANG Hongsheng E-mail:ingopro@qq.com;hszhang@shmtu.edu.cn
  • Supported by:
    National Natural Science Foundation of China(51679132);National Natural Science Foundation of China(51079082);Capacity Construction Project of Local University Base of Shanghai Science and Technology Commission(17040501600)

Abstract:

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.

Key words: ocean internal waves, SAR, Canny operator, contour classification, area ratio, directional characteristic, cosine fitting

CLC Number: 

  • P731.24