Optical flow-based method to estimate internal wave parameters from X-band marine radar images

作     者：Jinghan Wen Zhongbiao Chen Yijun He Jinghan Wen;Zhongbiao Chen;Yijun He

作者机构：School of Marine SciencesNanjing University of Information Science&TechnologyNanjing210044China Key Laboratory of Space Ocean Remote Sensing and ApplicationsNational Satellite Ocean Application ServiceBeijing100081China 

出 版 物：《Acta Oceanologica Sinica》 (海洋学报（英文版）)

年 卷 期：2022年第41卷第9期

页      面：149-157页

核心收录：

学科分类：0707[理学-海洋科学] 08[工学] 0816[工学-测绘科学与技术] 

基　　金：The National Natural Science Foundation of China under contract Nos 41620104003 and 42027805 the National Natural Science Youth Foundation of China under contract No.41506199 

主　　题：internal wave X-band marine radar optical flow phase velocity 

摘      要：The velocity and direction of internal waves(IWs) are important parameters of the ocean,however,traditional observation methods can only obtain the average parameters of IWs for a single location or large ***,a new method based on optical flow is proposed to derive the phase velocity vectors of IWs from X-band marine radar ***,the X-band marine radar image sequence is averaged,and ramp correction is used to reduce the attenuation of gray values with increasing radial ***,the average propagation direction of the IWs is determined using the two-dimensional Fourier transform of the radar images;two radial profiles along this direction are selected from two adjacent radar images;and then,the average phase velocity of the IWs is estimated from these radial ***,the averaged radar images are processed via histogram equalization and binarization to reduce the influence of noise on the radar ***,a weighting factor is determined using the average phase velocity of a reference point;the phase velocities on the wave crest of the IWs are subsequently estimated via the optical flow ***,the proposed method is validated using X-band marine radar image sequences observed on an oil platform in the South China Sea,and the error of the phase velocity is calculated to be 0.000 3–0.073 8 m/*** application conditions of the proposed method are also discussed using two different types of IW packets.