3D Suspended Sediment Concentration Mapping through GF-1 Satellite Image and Kriging-based Optimal Shipping Path Planning for Acoustic Subsurface Measurements

Understanding suspended sediment concentration (SSC) distribution is of great significance to the comprehensive management of offshore engineering, structure safety and landsea interaction material flux. Combing satellite remote sensing, which has the advantage on quickly and dynamically obtaining the spatial distribution of sea surface SSC with high spatial resolution and large scale spatial coverage, with the acoustic-based method, which is able to obtain high temporal and spatial resolution data along the vertical water column profile, has been proved as promising in obtaining three-dimensional SSC distribution in the target area. In this paper, based on the sea surface SSC map inversed from GF-1 satellite data, we intend to design optimal sampling route for acoustic-based in-situ measurement to maximize the environmental information with the least experiment cost. An optimal shipping path planning algorithm is proposed, in which the Kriging variance is utilized as a reward function to find the most informative sampling points, and the optimal sampling path is then planned to bring the ship as close as possible to those sampling points concerning the cost constraint. Meanwhile, we also use Voronoi polygon to accelerate the operation. The effectiveness of the algorithm is verified by the in-situ measurement near Zhoushan island. A 3D SSC map is then produced with satellite inversed surface SSC and subsurface SSC along the depth profile measured by acoustic based in-situ measurements in the planned optimal sampling routine. We also test the algorithm in a wider sea area with more complicated hydrodynamic environment based on the satellite SSC and proved to be suitable for supplementation of large-scale measurement network.