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Articles 1 - 6 of 6
Full-Text Articles in Physical Sciences and Mathematics
Terrain Constrained Stereo Correspondence, Gabrielle Inglis, Chris Roman
Terrain Constrained Stereo Correspondence, Gabrielle Inglis, Chris Roman
Christopher N. Roman
There is a persistent need in the oceanographic community for accurate three dimensional reconstructions of seafloor structures. To meet this need underwater mapping techniques have expanded to include the use of stereo vision and high frequency multibeam sonar for mapping scenes 10's to 100's of square meters in size. Both techniques have relative advantages and disadvantages that depend on the task at hand and the desired accuracy. In this paper, we develop a method to constrain the often problematic stereo correspondence search to small sections of the image that correspond to estimated ranges along the epipolar lines calculated from coregistered …
Application Of Structured Light Imaging For High Resolution Mapping Of Underwater Archaeological Sites, Chris Roman, Gabrielle Inglis, James Rutter
Application Of Structured Light Imaging For High Resolution Mapping Of Underwater Archaeological Sites, Chris Roman, Gabrielle Inglis, James Rutter
Christopher N. Roman
This paper presents results from recent work using structured light laser profile imaging to create high resolution bathymetric maps of underwater archaeological sites. Documenting the texture and structure of submerged sites is a difficult task and many applicable acoustic and photographic mapping techniques have recently emerged. This effort was completed to evaluate laser profile imaging in comparison to stereo imaging and high frequency multibeam mapping. A ROV mounted camera and inclined 532 nm sheet laser were used to create profiles of the bottom that were then merged into maps using platform navigation data. These initial results show very promising resolution …
Variable Morphologic Expression Of Volcanic, Tectonic, And Hydrothermal Processes At Six Hydrothermal Vent Fields In The Lau Back-Arc Basin, Vicki Lynn Ferrini, Margaret K. Tivey, Suzanne M. Carbotte, Fernando Martinez, Chris Roman
Variable Morphologic Expression Of Volcanic, Tectonic, And Hydrothermal Processes At Six Hydrothermal Vent Fields In The Lau Back-Arc Basin, Vicki Lynn Ferrini, Margaret K. Tivey, Suzanne M. Carbotte, Fernando Martinez, Chris Roman
Christopher N. Roman
Ultrahigh-resolution bathymetric maps (25 cm grid) are used to quantify the physical dimensions of and spatial relationships between tectonic, volcanic, and hydrothermal features at six hydrothermal vent fields in the Lau back-arc basin. Supplemented with near-bottom photos, and nested within regional DSL-120A side-scan sonar data, these maps provide insight into the nature of hydrothermal systems along the Eastern Lau Spreading Center (ELSC) and Valu Fa Ridge (VFR). Along-axis transitions evident in localized volcanic morphology and tectonic characteristics include a change from broad low-relief volcanic domes (hundreds of meters wide,tall) that are dominated by pillow and lobate lava morphologies and are …
Consistency Based Error Evaluation For Deep Sea Bathymetric Mapping With Robotic Vehicles, Christopher Roman, Hanumant Singh
Consistency Based Error Evaluation For Deep Sea Bathymetric Mapping With Robotic Vehicles, Christopher Roman, Hanumant Singh
Christopher N. Roman
This paper presents a method to evaluate the mapping error present in point cloud terrain maps created using robotic vehicles and range sensors. This work focuses on mapping environments where no a priori ground truth is available and self consistency is the only available check against false artifacts and errors. The proposed error measure is based on a disparity measurement between common sections of the environment that have been imaged multiple times. This disparity measure highlights inconsistency in the terrain map by showing regions where multiple overlapping point clouds do not fit together well. This error measure provides the map …
Improved Vehicle Based Multibeam Bathymetry Using Sub-Maps And Slam, Christopher Roman, Hanumant Singh
Improved Vehicle Based Multibeam Bathymetry Using Sub-Maps And Slam, Christopher Roman, Hanumant Singh
Christopher N. Roman
This paper presents an algorithm to improve sub-sea acoustic multibeam bottom mapping based on the simultaneous mapping and localization (SLAM) methodology. Multibeam bathymetry from underwater water vehicles can yield valuable large scale terrain maps of the sea door, but the overall accuracy of these maps is typically limited by the accuracy of the vehicle position estimates. The solution presented here uses small bathymetric patches created over short time scales in a sub-mapping context. These patches are registered with respect to one another and assembled in a single coordinate frame to produce a more accurate terrain estimate and provide improved renavigation …
Micro-Bathymetric Mapping Using Acoustic Range Images, Christopher Roman, Hanumant Singh
Micro-Bathymetric Mapping Using Acoustic Range Images, Christopher Roman, Hanumant Singh
Christopher N. Roman
This work focuses on the creation of high resolution micro-bathymetric maps using a high frequency pencil beam sonar. These maps typically cover areas of 10's to 100's of square meters. Data is collected using a sonar mounted to an underwater vehicle that can be positioned at discrete locations on the sea floor or flown in a survey pattern above the bottom. Specifically, we are focused on improving the accuracy of these terrain maps by merging sonar pings taken from multiple vantage points over the same location. This requires the adaption of data registration techniques to handle errors related to the …