Sources and Impacts of Bottom Slope Uncertainty on Estimation of Seafloor Backscatter from Swath Sonars

Seafloor backscatter data from multibeam echosounders are now widely used in seafloor characterization studies. Accurate and repeatable measurements are essential for advancing the success of these techniques. This paper explores the impact of uncertainty in our knowledge of the local seafloor slope...

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Main Author: Mashkoor Malik
Format: Article
Language:English
Published: MDPI AG 2019-04-01
Series:Geosciences
Subjects:
Online Access:https://www.mdpi.com/2076-3263/9/4/183
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spelling doaj-52a7d027ca3a465592d432f6c111b7022020-11-24T21:20:56ZengMDPI AGGeosciences2076-32632019-04-019418310.3390/geosciences9040183geosciences9040183Sources and Impacts of Bottom Slope Uncertainty on Estimation of Seafloor Backscatter from Swath SonarsMashkoor Malik0NOAA Office of Ocean Exploration and Research, 1315 East West Highway, Silver Spring, MD 20910, USASeafloor backscatter data from multibeam echosounders are now widely used in seafloor characterization studies. Accurate and repeatable measurements are essential for advancing the success of these techniques. This paper explores the impact of uncertainty in our knowledge of the local seafloor slope on the overall accuracy of the backscatter measurement. Amongst the various sources of slope uncertainty studied, the impact of bathymetric uncertainty and scale were identified as the major sources of slope uncertainty. The bottom slope affects two important corrections needed for estimating seafloor backscatter: (1) The insonified area and; (2) the seafloor incidence angle. The impacts of these slope-related uncertainty sources were quantified for a shallow water multibeam survey. The results show that the most significant uncertainty in backscatter data arises when seafloor slope is not accounted for or when low-resolution bathymetry is used to estimate seafloor slope. This effect is enhanced in rough seafloors. A standard method of seafloor slope correction is proposed to achieve repeatable and accurate backscatter results. Additionally, a standard data package, including metadata describing the slope corrections applied, needs to accompany backscatter results and should include details of the slope estimation method and resolution of the bathymetry used.https://www.mdpi.com/2076-3263/9/4/183Swath mappingseafloor incidence angleseafloor slopeuncertainty
collection DOAJ
language English
format Article
sources DOAJ
author Mashkoor Malik
spellingShingle Mashkoor Malik
Sources and Impacts of Bottom Slope Uncertainty on Estimation of Seafloor Backscatter from Swath Sonars
Geosciences
Swath mapping
seafloor incidence angle
seafloor slope
uncertainty
author_facet Mashkoor Malik
author_sort Mashkoor Malik
title Sources and Impacts of Bottom Slope Uncertainty on Estimation of Seafloor Backscatter from Swath Sonars
title_short Sources and Impacts of Bottom Slope Uncertainty on Estimation of Seafloor Backscatter from Swath Sonars
title_full Sources and Impacts of Bottom Slope Uncertainty on Estimation of Seafloor Backscatter from Swath Sonars
title_fullStr Sources and Impacts of Bottom Slope Uncertainty on Estimation of Seafloor Backscatter from Swath Sonars
title_full_unstemmed Sources and Impacts of Bottom Slope Uncertainty on Estimation of Seafloor Backscatter from Swath Sonars
title_sort sources and impacts of bottom slope uncertainty on estimation of seafloor backscatter from swath sonars
publisher MDPI AG
series Geosciences
issn 2076-3263
publishDate 2019-04-01
description Seafloor backscatter data from multibeam echosounders are now widely used in seafloor characterization studies. Accurate and repeatable measurements are essential for advancing the success of these techniques. This paper explores the impact of uncertainty in our knowledge of the local seafloor slope on the overall accuracy of the backscatter measurement. Amongst the various sources of slope uncertainty studied, the impact of bathymetric uncertainty and scale were identified as the major sources of slope uncertainty. The bottom slope affects two important corrections needed for estimating seafloor backscatter: (1) The insonified area and; (2) the seafloor incidence angle. The impacts of these slope-related uncertainty sources were quantified for a shallow water multibeam survey. The results show that the most significant uncertainty in backscatter data arises when seafloor slope is not accounted for or when low-resolution bathymetry is used to estimate seafloor slope. This effect is enhanced in rough seafloors. A standard method of seafloor slope correction is proposed to achieve repeatable and accurate backscatter results. Additionally, a standard data package, including metadata describing the slope corrections applied, needs to accompany backscatter results and should include details of the slope estimation method and resolution of the bathymetry used.
topic Swath mapping
seafloor incidence angle
seafloor slope
uncertainty
url https://www.mdpi.com/2076-3263/9/4/183
work_keys_str_mv AT mashkoormalik sourcesandimpactsofbottomslopeuncertaintyonestimationofseafloorbackscatterfromswathsonars
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