Download or read book Mapping Underwater Environments with Imaging Sonar written by Joshua Morgan and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Imaging sonar can be used for vision-based navigation and mapping of underwater environments. For example, an autonomous underwater vehicle may use sonar to detect waste on a lakebed or inspect the hull of a ship for defects. For these applications, acoustic images are less sensitive to water conditions than optical images, which makes sonar the ideal vision sensor. This thesis presents a new framework for using sonar video to produce a mosaic image of an underwater environment. The proposed mosaicking technique contains three stages. These stages include ground plane projection, motion estimation, and mosaic rendering. The mosaicking algorithm in this thesis adds several unique contributions to prior research. First, the ground plane projection model allows the algorithm to handle video recorded by sonar with a large tilt angle. Additionally, the motion estimation stage introduces an image registration algorithm which combines Fourier-based and least squares methods. This approach leads to a superior method for calculating registration covariances, which is important for combining measurements into a full vehicle trajectory estimate. Another contribution is the application of a graph-based localization technique to fuse sonar image registration with periodic GPS measurements.