Modeling and Analysis of Sea-Surface Vehicle System for Underwater Mapping Using Single-Beam Echosounder

Abstract

Detailed knowledge on the shape of the seafloor is crucial for many researchers. Bathymetric data are critical for navigational safety and are used for underwater mapping. This study develops a sea-surface vehicle (SSV) system for underwater mapping by using both bathymetric data from a low-cost single-beam echosounder located on the SSV, and the navigation data of the SSV. The navigation of the SSV was obtained using a global positioning system (GPS). The effect of changing bathymetric and navigation data due to external disturbances such as wind and waves on the map was analyzed. The sea-bottom slope angles, which are effective in changing bathymetric data, were estimated and corrected in relation to the estimated angles in a particular mapped area for more accurate underwater mapping. Additionally, the effects of the grid range of the mapped area, beam angle of the echosounder, and position of the echosounder on the underwater mapping were analyzed. These analyses were based on simulation data, and were performed in a MATLAB, HYPACK, and Global Mapper environment. An underwater map was also obtained in the Kozlu/Zonguldak area, Black Sea by using a single-beam echosounder located on the SSV. This map was improved by estimating sea-bottom slope angles and the corrected bathymetric data to obtain a more accurate underwater map of the area. The experimental and simulation results were compared, focusing on the sea-bottom slope changes, sea-surface disturbances, bathymetry grid range changes, and draft effects.

Low-cost Underwater Localisation Using Single-Beam Echosounders and Inertial Measurement Units

“…Previous work is indicative of similar motivations and methodology when compared with this study. Device and computational inabilities experienced in past works may no longer be applicable now, e.g., Kartal et al [9] in their work explored the possibility of collecting bathymetric data from seabeds sloped in two axes using one single-beam SONAR. Simulations, powerful computing, and the ease of conducting real-life experiments makes it possible to conduct such studies.…”

A Comparison of Different Gis-Based Interpolation Methods for Bathymetric Data: Case Study of Bawean Island, East Java

“…= − − − + − (Kartal et al, 2022), where SL is the "source level", a measurement of a sound source's power emitted, more specifically it is a measurement of its far-field radiant intensity; TL is the "transmission loss", the difference between the signal level received at the sonar and the SL, which is the inverse of the transfer function from source to receiver; NL is "noise level", the degree of undesired noise or non-acoustic noise interfering with the sonar signal; DI is the "directivity index", as a rough estimate of the array gain; BS is the "bottom backscattering strength", used for assessing an accurate mapping and categorization of the seafloor; and DT is the "detection threshold" as the space-time processor (Ainslie & Leighton, 2016;Solikin et al, 2018;Yang et al, 2018). However, there will be several sites where the SBES has not assessed the depth.…”

Testing the Effect of Bathymetric Data Reduction on the Shape of the Digital Bottom Model

“…There are several survey systems for acquiring the water depth data, while their operating principle, operating environment, and delivered measurement accuracy significantly differ [ 18 ]. Currently, the most widely used measurement system is a multibeam system, which functions on the principles of aquatic acoustics [ 19 , 20 , 21 ] due to the significant limitations of electromagnetic wave propagation in the water medium [ 22 , 23 , 24 ]. The basic device of the multibeam system is a multibeam echosounder (MBES), which allows for the measurement of the depth distribution of a body of water.…”