Research On Measurement Of Seabed Sediment Roughness And Classification Of Sediments

The detection of seabed sediments is of great significance for both military and civilian use.Marine resources are in urgent need of human development and detection,and detection means is a guarantee for obtaining marine information.This paper first introduces the commonly used means of seabed sediment detection,and discusses the development history and current situation of the geoacoustic scattering model and experimental research.The work of this thesis is mainly based on the geoacoustic scattering model,which is carried out around the two major points of roughness parameter measurement and sediment classification in the field of seabed sediment detection.The geoacoustic scattering model is an important model for explaining the intrinsic mechanism of the relationship between acoustic waves and sediment properties.Firstly,this paper studies and simulates the classical scattering acoustic model of the seabed,the Jackson scattering model.According to the Jackson scattering model,the model parameters can be input to obtain the angular response of the received sound intensity in the case of backscattering.However,there are many parameters affecting the geoacoustic relationship.Based on the Sobol method,the model parameter sensitivity analysis is carried out.The roughness parameter has an important influence on the whole,so the measurement work for this parameter is carried out in this paper.Sediments tend to have the structural characteristics of loose particles,and their original structure is easily destroyed after salvage.Existing in-situ measurement methods have shortcomings in terms of convenience and speed of implementation.Therefore,sediment roughness parameters urgently require a rapid in-situ measurement method.In this paper,a seafloor microtopography roughness measurement method based on the underwater shape from shading algorithm is proposed.This algorithm can be used to obtain submarine micro-topography data from the light and dark information in a single photo.In this paper,the shape from shading algorithm is extended to underwater,and the three-dimensional seabed micro-topography is obtained by this method to extract roughness parameters.Experimental proves the effectiveness of the algorithm.The geoacoustic scattering model is also an important basis for sediment classification.Based on the Jackson scattering model,the echo envelope model obtained by single-beam sonar detection of seafloor sediments is deduced and simulated in detail.The echo envelope is denoised by wavelet transform and principal component analysis,and then the classification and recognition are carried out.The classification results correspond to the simulated true values,which proves the effectiveness of sediment classification based on the submarine echo envelope.