| The internal wave is a common mesoscale phenomenon in the ocean,and it is common in all major oceans around the world.The internal wave not only plays an important role in the transportation of substances in seawater and the mixing of seawater,but also has a greater impact on human production activities in the ocean.Serious conditions may even cause significant loss of life and property.With the rapid development of remote sensing technology,the use of remote sensing images to observe ocean internal waves has become an important means of studying internal waves.Compared with the traditional on-site method of measuring internal waves,remote sensing methods are not restricted by regions,have a large coverage area,and have a richer amount of data,which provides an important data source guarantee for effective research on internal waves.Therefore,the thesis combines remote sensing technology to carry out research on the intensity of internal waves,so as to avoid the significant losses caused by ocean internal waves to human production and life.The length of the peak line of the internal wave of the ocean can reach hundreds of kilometers,the maximum amplitude is more than 200 m,and it carries huge energy.The thesis mainly studies the internal wave intensity,and uses the satellite SAR remote sensing image combined with the internal wave amplitude inversion model to construct the internal wave intensity classification model.Extract the internal wave information from the remote sensing image and combine the internal wave amplitude inversion model to calculate the internal wave intensity.Then use the measured data for comparative analysis to verify the accuracy of the model.Finally,this intensity analysis technique is applied to the areas where internal waves mainly occur in the South China Sea,Sulu Sea,Andaman Sea.The calculation results are analyzed to verify the reliability of the model.The thesis mainly completes the following parts:1.Design of internal wave amplitude inversion model: different internal wave amplitude inversion models are adopted according to the water depth range.In this paper,the classic KdV equation method and the parametric floating frequency method with higher accuracy for shallow water depth values are used.The KdV equation is divided into a two-layer model and a continuouslayered model.The paper analyzes the application of these three methods.Conditions,combined with experience and hydrological conditions in various regions,adopt corresponding internal wave amplitude inversion methods for different internal waves to calculate various parameters of internal waves.2.Collect the data set needed to establish the internal wave intensity model: The establishment of the internal wave intensity model needs to be based on sufficient data support.The data set in this paper is divided into water depth data set,temperature and salt data set,SAR remote sensing image data set and measured data set in the study area.The internal wave samples in the SAR remote sensing data set are internal wave images intercepted after the preprocessing of internal wave original data,such as screening and geometric correction.The measured data set contains the measured data and the internal wave SAR remote sensing image that can be matched with it.3.Calculate the internal wave intensity: Firstly obtain the internal wave wavelength and the latitude and longitude information of the internal wave from the internal wave remote sensing image,and calculate the vertical density curve and floating frequency curve of the location by combining the water depth data and the temperature and salt data.The internal wave wavelength analysis determines the method used for internal wave amplitude inversion,calculates the internal wave amplitude and propagation velocity;and finally establishes the internal wave spatial structure,calculates the internal wave energy and quantifies it as the internal wave intensity.4.Verification of the internal wave intensity model: After the model is completed,the accuracy is confirmed by verification.This article uses a method of comparison with the measured data to verify,mainly on the accuracy of the internal wave amplitude,internal wave energy and internal wave intensity of the inversion verification.In this paper,a total of 6 pairs of matched data from the field and remote sensing were selected for comparative analysis to prove the accuracy of the internal wave intensity model.5.Application of the model completed in this paper: The internal wave intensity model constructed in this paper is applied to the South China Sea,Sulu Sea and Andaman Sea,and the internal wave intensity in the study area is calculated,and the calculation results are processed and analyzed.The relationship between wave intensity and internal wave amplitude change,internal wave intensity and water depth change,and the seasonal variation of internal wave intensity. |
