Underwater terrain-aided navigation is used to complement the traditional inertial navigation employed by autonomous underwater vehicles during lengthy missions. It can provide fixed estimations by matching real-time ...Underwater terrain-aided navigation is used to complement the traditional inertial navigation employed by autonomous underwater vehicles during lengthy missions. It can provide fixed estimations by matching real-time depth data with a digital terrain map, This study presents the concept of using image processing techniques in the underwater terrain matching process. A traditional gray-scale histogram of an image is enriched by incorporation with spatial information in pixels. Edge comer pixels are then defined and used to construct an edge comer histogram, which employs as a template to scan the digital terrain map and estimate the fixes of the vehicle by searching the correlation peak. Simulations are performed to investigate the robustness of the proposed method, particularly in relation to its sensitivity to background noise, the scale of real-time images, and the travel direction of the vehicle. At an image resolution of 1 m2/pixel, the accuracy of localization is more than 10 meters.展开更多
Shallow marine sand waves are formed on the seabed and are widely distributed within tidal environments.However,the use of multibeam echo sounding(MBES)is costly to obtain the bathymetric mapping of large complex sand...Shallow marine sand waves are formed on the seabed and are widely distributed within tidal environments.However,the use of multibeam echo sounding(MBES)is costly to obtain the bathymetric mapping of large complex sand waves.Therefore,we propose a new method that employs a combination of multiangle sun glint images and sparse MBES data to achieve comprehensive bathymetric mapping of large and complex sand waves.This method involves estimating sea surface roughness,automatically extracting sand-wave crests,conducting adaptive subregion partitioning,estimating the water depth at auxiliary points,and generating digital bathymetric models.The method was employed in a case study of sand waves on the Taiwan Bank.Bathymetric mapping was implemented for large complex sand waves over an area spanning approximately 350 km~2 using multiangle sun glint images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer and MBE S data.The results show that mapped and measured water depths were well-matched;the root-mean-square error of water depths was 1.77 m,and the relative error was 5.03%.These findings show that bathymetric mapping of large complex sand waves can be effectively conducted using the new method,and as such,the workload of MBES is reduced and efficiency is improved.展开更多
基金Supported by the National Natural Nature Science Foundation of China （Grant No. 41376102）, Fundamental Research Funds for the Central Universities （Gant No. HEUCF150514） and Chinese Scholarship Council （Grant No. 201406680029）.
文摘Underwater terrain-aided navigation is used to complement the traditional inertial navigation employed by autonomous underwater vehicles during lengthy missions. It can provide fixed estimations by matching real-time depth data with a digital terrain map, This study presents the concept of using image processing techniques in the underwater terrain matching process. A traditional gray-scale histogram of an image is enriched by incorporation with spatial information in pixels. Edge comer pixels are then defined and used to construct an edge comer histogram, which employs as a template to scan the digital terrain map and estimate the fixes of the vehicle by searching the correlation peak. Simulations are performed to investigate the robustness of the proposed method, particularly in relation to its sensitivity to background noise, the scale of real-time images, and the travel direction of the vehicle. At an image resolution of 1 m2/pixel, the accuracy of localization is more than 10 meters.
基金Supported by the National Natural Science Foundation of China(Nos.41876208,41830540,41576174)。
文摘Shallow marine sand waves are formed on the seabed and are widely distributed within tidal environments.However,the use of multibeam echo sounding(MBES)is costly to obtain the bathymetric mapping of large complex sand waves.Therefore,we propose a new method that employs a combination of multiangle sun glint images and sparse MBES data to achieve comprehensive bathymetric mapping of large and complex sand waves.This method involves estimating sea surface roughness,automatically extracting sand-wave crests,conducting adaptive subregion partitioning,estimating the water depth at auxiliary points,and generating digital bathymetric models.The method was employed in a case study of sand waves on the Taiwan Bank.Bathymetric mapping was implemented for large complex sand waves over an area spanning approximately 350 km~2 using multiangle sun glint images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer and MBE S data.The results show that mapped and measured water depths were well-matched;the root-mean-square error of water depths was 1.77 m,and the relative error was 5.03%.These findings show that bathymetric mapping of large complex sand waves can be effectively conducted using the new method,and as such,the workload of MBES is reduced and efficiency is improved.
