海洋科学2023，Vol.47Issue(11)：79-96,18.DOI:10.11759/hykx20220819001
基于无人机光学图像的海流观测方法研究
Method to retrieve ocean current from optical images based on UAV
摘要
Abstract
Ocean current information is important for marine navigation and resource exploration,but traditional on-site and remote sensing observation methods fail to meet the requirements of large-area and real-time current observation.Optical ocean remote sensing technology based on a UAV platform demonstrates the characteristics of flexibility,low cost,and high resolution and has been applied in marine environment monitoring in recent years.However,since small UAVs are easily affected by flying attitude,solar flares,and other factors,they are not adept in ocean current observation.This study presents a method to retrieve sea surface current from optical images ob-tained by a small UAV,and the influences of different ingredients on the observation results are analyzed.First,the optical sea surface image acquired by the UAV is preprocessed to eliminate the influences of geometric imaging and noise,and the influence of sun glint on the image is reduced by analyzing the average gray value of the images.Then,the current is retrieved through an algorithm based on 3D fast Fourier transform and wave dispersion rela-tionship,and the inversion results are compared with the ocean current data measured using the buoy,thus verifying the method's reliability.Second,combined with the experimental data,the influence of different factors on ocean current inversion is analyzed in detail under the experimental conditions in this paper(effective wave height 0.2-1.5 m,main wave period 3.8-5.7 s).When the spatial resolution is 0.15 m,and the size of the study region is 2-3 times the dominant wavelength,the inversion error of the current becomes the smallest.Increasing the number of images and the temporal resolution of images are also beneficial to improving the inversion accuracy of ocean currents.The results show that the method proposed to estimate sea surface current from optical images obtained by UAV can be used to obtain the sea surface current field.关键词
光学遥感/无人机/海流/反演方法Key words
optical remote sensing/UAV/sea surface current/inversion method分类
天文与地球科学引用本文复制引用
杨静,陈忠彪,何宜军,孙闰霞..基于无人机光学图像的海流观测方法研究[J].海洋科学,2023,47(11):79-96,18.基金项目
国家自然科学基金项目(41506199,41977302) （41506199,41977302）
国家自然科学基金重大仪器设备研制项目(42027805)National Natural Science Foundation of China,Nos.41506199,41977302,42027805 （42027805）
