Abstract
Because the safety of the navigation depends on accurate knowledge of the submerged features, any improvements in the ability to resolve those features are of major interest. Ultimately this reflects the bottom detection performance of the bathymetric measuring system (most commonly multibeam sonar) utilized. The two most common techniques are designed around time-series or angle-series analysis, although by far the most focus has been on time-series. The newly available option of recording both amplitude and phase data of the water column permit the development and testing of new algorithms to be carried out in post-processing.
This research evaluates the use of water column data to perform bottom detection in a nonconventional way, that is, analyzing angle-series instead of time-series. The proposed algorithm is based on the BDI method with the new inclusion of phase information. Such a method, termed Phase Deviation Indicator (PDI), can be applied in an alternative and mainly complementary way to the currently existing methods.
The results obtained indicate that there are cases in which the analysis made only within a time-series, even using multi-detection features, can be incomplete and could be complemented by the analysis made within a beam-series (PDI). Particularly notable geometries included mast-like-objects, discontinuous surfaces or features whose lateral extent is confined mostly within a short range of incidence angles, thereby requiring multiple detections within the same beam. Such results emphasize the idea that the best detection method results from the integrated use of all available techniques.
Presenter Bio
Leonardo Gomes de Araujo graduated with a bachelor's degree in Nautical Science, with a major in Electronics, from the Brazilian Navy Academy in 2008. He performed an Extension Course in Hydrography (IHO Cat A), offered by the Brazilian Directorate of Hydrography and Navigation (DHN), in 2011. Since then, he has been working in Brazilian Navy Hydrographic Ships, using single beam and multibeam echosounders. Before coming to CCOM/UNH, he was the Captain of the Hydro-Oceanographic Fluvial Vessel Caravelas, heading hydrographic surveys in Paraguay River as well as its affluent rivers, in the "Pantanal" region of Brazil.
Leo is now pursuing a master's degree in earth sciences/ocean mapping to expand his knowledge and improve his technical qualification as a future member of the Bathymetry Section at the Brazilian Navy Hydrographic Center, which has to analyze, categorize and approve all Hydrographic Surveys conducted in Brazilian Jurisdictional Waters. In his free time, he enjoys taking care of his little son, traveling with his wife and friends, watching movies, and chatting about ocean mapping.
Publication Date
9-24-2020
Document Type
Presentation
Recommended Citation
de Araujo, Leonardo Gomes, "Potential for Non-Conventional Use of Split-Beam Phase Data in Bottom Detection" (2020). Seminars. 311.
https://scholars.unh.edu/ccom_seminars/311