3D Suspended Sediment Acoustic Observation Technology With Satellite Remote Sensing Data Fusion

In recent years,with the full development of various observation technologies,ocean observation capabilities have been greatly enhanced.How to combine multiplatform,multi-method,and multi-dimensional observation methods to carry out stereoscopic observation of the ocean environment is a hot issue and a difficult point in marine observation.In view of this,this paper combines the acoustic observation technology with the ability to observe underwater vertical dimensions and the ocean optical satellite remote sensing technology that can obtain large-scale sea surface parameters.Aiming at the characteristics of the hydrodynamic environment near the estuary in China,considering the availability of ocean satellite remote sensing data and the characteristics of temporal and spatial resolution,we take suspended sediment concentration as a specific observation parameter and propose a 3D water body acoustic observation which incorporates satellite remote sensing data.The main idea of integrated technology is to observe dynamic sea areas with large spatiotemporal range based on data-driven modal decomposition algorithm.By using the modal decomposition algorithm for the timeseries remote sensing data in the target sea area,the spatial distribution pattern of the physical parameters of the sea surface can be obtained,and the best sampling point can be found by QR decomposition and cost constraints.At the same time,sparse sampling is used to cooperate with the spatial distribution mode of sea surface physical parameters to achieve sparse reduction,so as to obtain the suspended sediment concentration distribution of the entire three-dimensional ocean.For special sea areas with high spatial resolution requirements and poor availability of satellite remote sensing data,a Kriging interpolation method based on spatial statistics is specially designed as a complementary algorithm,which is mainly applicable to the observation of static sea areas in the small space-time range.Specifically,a single-view satellite remote sensing image is used as a data source,and the algorithm is used to calculate the importance of each position in the target area.The optimal sampling position is determined using a search strategy,and the ship route is designed using an optimization algorithm to ensure a smaller cost to get enough acoustic data.Finally,the entire three-dimensional ocean suspended sediment concentration distribution was restored by Kriging interpolation combined with surface remote sensing data.We conducted two experiments in the Zhoushan sea area,and collected the measured data for algorithm verification,,and the results show that the Kriging interpolation algorithm can complete the observation of special sea areas in small areas,and the modal decomposition algorithm realizes the observation of large-scale dynamic sea areas.These methods are complementary to each other,so that it is expected to realize three-dimensional,time-series observations in a dynamic ocean environment.