Open Access. Powered by Scholars. Published by Universities.®

Mechanical Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Selected Works

Oceanography and Atmospheric Sciences and Meteorology

Underwater acoustics

Publication Year

Articles 1 - 4 of 4

Full-Text Articles in Mechanical Engineering

Improved Vehicle Based Multibeam Bathymetry Using Sub-Maps And Slam, Christopher Roman, Hanumant Singh Jul 2005

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 Oct 2004

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 …


Optical And Acoustic Habitat Characterization With The Seabed Auv, Hanumant Singh, Ryan Eustice, Oscar Pizarro, Christopher Roman Aug 2003

Optical And Acoustic Habitat Characterization With The Seabed Auv, Hanumant Singh, Ryan Eustice, Oscar Pizarro, Christopher Roman

Christopher N. Roman

The Seabed AUV is an Autonomous Underwater Vehicle (AUV) built to serve as a readily available and operationally simple tool for high resolution imaging. It is a hover-capable vehicle that performs optical sensing with a 12 bit 1280/spl times/1024 CCD camera and acoustic high resolution mapping using an MST 300 kHz sidescan and a 675 kHz pencil beam bathymetric sonar. The AUV has been designed for operations from small vessels with minimal support equipment. It has an operational depth of 2000 meters and at 1 m/s can run for up to 10 hours. In this paper we report on the …


Advances In Fusion Of High Resolution Underwater Optical And Acoustic Data, H. Singh, C. Roman, L. Whitcomb, D. Yoerger Apr 2000

Advances In Fusion Of High Resolution Underwater Optical And Acoustic Data, H. Singh, C. Roman, L. Whitcomb, D. Yoerger

Christopher N. Roman

We report efforts to merge data from the complementary modalities of optical and acoustic sensing for obtaining more accurate representations of the seafloor. We show that the principal obstacles to merging the acoustic and optical imaging modalities are the distortions inherent to each modality. The construction of geometrically accurate photomosaics is dominated by incremental errors arising as individual images are scaled and warped to form the photomosaic. For microbathymetric mapping, principal errors arise from sensor position and orientation calibration parameters that affect our ability to construct maps from sonar data that are commensurate with sensor and navigation resolution. We show …