To achieve accurate positioning of autonomous underwater vehicles, an appropriate underwater terrain database storage format for underwater terrain-matching positioning is established using multi-beam data as underwat...To achieve accurate positioning of autonomous underwater vehicles, an appropriate underwater terrain database storage format for underwater terrain-matching positioning is established using multi-beam data as underwater terrainmatching data. An underwater terrain interpolation error compensation method based on fractional Brownian motion is proposed for defects of normal terrain interpolation, and an underwater terrain-matching positioning method based on least squares estimation（LSE） is proposed for correlation analysis of topographic features. The Fisher method is introduced as a secondary criterion for pseudo localization appearing in a topographic features flat area, effectively reducing the impact of pseudo positioning points on matching accuracy and improving the positioning accuracy of terrain flat areas. Simulation experiments based on electronic chart and multi-beam sea trial data show that drift errors of an inertial navigation system can be corrected effectively using the proposed method. The positioning accuracy and practicality are high, satisfying the requirement of underwater accurate positioning.展开更多
Based on the integrated results of multiple data types including MBES (Multi-Beam Echo Sounding) and historical topography maps,the LSR (Linear Sand Ridges) on the ECS (East China Sea) shelf are identified,divided int...Based on the integrated results of multiple data types including MBES (Multi-Beam Echo Sounding) and historical topography maps,the LSR (Linear Sand Ridges) on the ECS (East China Sea) shelf are identified,divided into subareas,and classified.The distribution of sand ridge crests is also established.The strikes of the LSR on the ECS shelf fall in a normal distribution with the center point being 155° azimuth with additional peak points at 125°,130°,140°,and 180° azimuth.The distribution of the ECS shelf sand ridges is congested in the central area,sparse in the south and north ends,divergent and bifurcated in the eastern area,and densely convergent in the western area.The LSR are divided into seven subzones according to the strikes and distribution of the sand ridges;estuary mouth ridges and open shelf sand ridges are identified and marked out.The high amplitude change of sea level resulting from the glacial-interglacial cycle is the main cause of the vast development of sand ridges on the ECS shelf.Abundant sediments on the shelf carried by the PYR (Paleo-Yangtze River) are the material source for the LSR formation,and the negative seafloor topography influences the strikes of LSR.Based on the effects of LSR distribution,change of sea level,and the simulation of ancient tidal currents,the evolution of the LSR on the ECS shelf is divided into four main stages:Stage Ⅰ before 14.5 ka BP,Stage Ⅱ between 12 and 14 ka BP,Stage Ⅲ from 1.5 to 9.5 ka BP,and Stage Ⅳ after 9 ka BP.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51179035 and 51279221)the Natural Science Foundation of Heilongjiang Province(Grant No.E201121)
文摘To achieve accurate positioning of autonomous underwater vehicles, an appropriate underwater terrain database storage format for underwater terrain-matching positioning is established using multi-beam data as underwater terrainmatching data. An underwater terrain interpolation error compensation method based on fractional Brownian motion is proposed for defects of normal terrain interpolation, and an underwater terrain-matching positioning method based on least squares estimation（LSE） is proposed for correlation analysis of topographic features. The Fisher method is introduced as a secondary criterion for pseudo localization appearing in a topographic features flat area, effectively reducing the impact of pseudo positioning points on matching accuracy and improving the positioning accuracy of terrain flat areas. Simulation experiments based on electronic chart and multi-beam sea trial data show that drift errors of an inertial navigation system can be corrected effectively using the proposed method. The positioning accuracy and practicality are high, satisfying the requirement of underwater accurate positioning.
基金supported by National Natural Science Foundation of China (Grant Nos.40506017,40876051)Oceanic Research Project (Nos.908-ZC-Ⅰ-07,908-ZC-Ⅱ-05)
文摘Based on the integrated results of multiple data types including MBES (Multi-Beam Echo Sounding) and historical topography maps,the LSR (Linear Sand Ridges) on the ECS (East China Sea) shelf are identified,divided into subareas,and classified.The distribution of sand ridge crests is also established.The strikes of the LSR on the ECS shelf fall in a normal distribution with the center point being 155° azimuth with additional peak points at 125°,130°,140°,and 180° azimuth.The distribution of the ECS shelf sand ridges is congested in the central area,sparse in the south and north ends,divergent and bifurcated in the eastern area,and densely convergent in the western area.The LSR are divided into seven subzones according to the strikes and distribution of the sand ridges;estuary mouth ridges and open shelf sand ridges are identified and marked out.The high amplitude change of sea level resulting from the glacial-interglacial cycle is the main cause of the vast development of sand ridges on the ECS shelf.Abundant sediments on the shelf carried by the PYR (Paleo-Yangtze River) are the material source for the LSR formation,and the negative seafloor topography influences the strikes of LSR.Based on the effects of LSR distribution,change of sea level,and the simulation of ancient tidal currents,the evolution of the LSR on the ECS shelf is divided into four main stages:Stage Ⅰ before 14.5 ka BP,Stage Ⅱ between 12 and 14 ka BP,Stage Ⅲ from 1.5 to 9.5 ka BP,and Stage Ⅳ after 9 ka BP.
