Cross-Comparison of the “BathySent” Coastal Bathymetry to Sonar Measurements and Ratio Model Technique: Pilot Sites in the Aegean Sea (Greece)
Paraskevi DrakopoulouIoannis P. PanagiotopoulosMarcello de MicheleVasilios KapsimalisDaniel RaucoulesMichael FoumelisIoannis MorfisIsidoros LivanosDimitris SakellariouDimitris Vandarakis
0
Citation
31
Reference
10
Related Paper
Abstract:
The proposed novel “BathySent” approach for coastal bathymetric mapping, using the Copernicus Sentinel-2 mission, as well as the assessment and specification of the uncertainties of the derived depth results, are the objectives of this research effort. For this reason, Sentinel-2 bathymetry retrieval results for three different pilot sites in Greece (islands of Kos, Kasos, and Crete) were compared with ground-truth data. These data comprised high-resolution swath bathymetry measurements, single-beam echosounder measurements at very shallow waters (1–10 m), and the EMODnet DTM 2018 release. The synthetic tests showed that the “BathySent” approach could restitute bathymetry in the range of 5–14 m depth, showing a standard deviation of 2 m with respect to the sonar-based bathymetry. In addition, a comparison with the “ratio model” multispectral technique was performed. The absolute differences between conventional Earth Observation-based bathymetry retrieval approaches (i.e., linear ratio model) and the suggested innovative solution, using the Sentinel-2 data, were mainly lower than 2 m. According to the outcome evaluation, both models were considered to provide results that are more reliable within the depth zone of 5–25 m. The “ratio model” technique exhibits a saturation at ~25 m depth and demands ground calibration. Though, the “BathySent” method provides bathymetric data at a lower spatial resolution compared to the “ratio model” technique; however, it does not require in situ calibration and can also perform reliably deeper than 25 m.Keywords:
Ground truth
Echo sounding
In several sonar studies, bathymetric information; is used for the correction of amplitude data and the calculation of backscattering strength, which is plotted versus grazing angle and used for seabed classification. Bathymetric data is also used as an easily viewed backdrop to visualize backscattered sonar data in surveys. This work proposes an automatic method that combines amplitude features (describing backscattering strength and sonar texture) with bathymetric features (indicating seafloor variability) for sonar classification. Features are selected per window (of user defined size) and areas around grab samples in a survey are used for training. The importance of bathymetric features is investigated in this study, and highlighted by feature selection algorithms as well as by scatter plots exploring the training areas. Classification rates are significantly improved when both amplitude and bathymetry features are used. The final results show the classified windows plotted versus their exact position in the survey. The method described in this work is applied to a sidescan bathymetric sonar dataset taken in Hopvagen Bay Norway. The methods are also applicable to other sonars which provide bathymetric information; a multibeam sonar is such an example.
Seabed
Backscatter (email)
Target strength
Cite
Citations (1)
Kum, B.-C.; Shin, D.-H.; Jang, S.; Lee, S.Y.; Lee, J.H.; Moh, T.J.; Lim, D.G.; Do, J.-D., and Cho, J.H., 2020. Application of unmanned surface vehicles in coastal environments: Bathymetric survey using a multibeam echosounder. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 1152-1156. Coconut Creek (Florida), ISSN 0749-0208.This paper presents the practical application and results of a bathymetric survey carried out in a shallow marine coastal zone (Hujeong beach, located in the East Sea, South Korea) using a multi-functional unmanned surface vehicle (USV) equipped with a multibeam echosounder. Operation of the USV was conducted along the coast in very shallow water [depth ≤ 1.5 m (0.3 m below the transducer)], which is inaccessible to manned research vessels. High-resolution bathymetric data is expected to help with assessment and prediction of rapid changes in the shallow coastal zone. This work supports the applicability of USVs to scientific research and environmental monitoring in very shallow coastal areas. The USV will be the most extensively used technique for observing marine coastal environment.
Echo sounding
Unmanned surface vehicle
Cite
Citations (12)
Abstract Cutter, G. R. Jr, Berger, L., and Demer, D. A. 2010. A comparison of bathymetry mapped with the Simrad ME70 multibeam echosounder operated in bathymetric and fisheries modes. – ICES Journal of Marine Science, 67: 1301–1309. The Simrad ME70 multibeam echosounder was designed for quantitative fisheries research and is currently installed on Ifremer's fishery survey vessel (FSV) “Thalassa” and each of the new, quiet, NOAA FSVs. The ME70 has configurable beams and transmits in the range 70–120 kHz to provide calibrated, acoustic-backscattering data throughout the detection range (fisheries mode, FM). With optional hardware and software, the ME70 can also collect soundings that potentially meet International Hydrographic Organization's S–44 Order 1 standards (bathymetric mode, BM). Furthermore, with custom algorithms and software, bathymetric data can be obtained from the ME70 operating in FM, and volume backscatter can be sampled from the ME70 operating in BM. This flexibility allows data to be concurrently collected on fish and their seabed habitat. A method is described for processing the echo amplitude and phase data from multiple split-beams formed in FM to estimate seabed range, slope, and roughness. The resulting bathymetry is compared with that collected with the ME70 operating in BM in the same area of the Bay of Biscay. A proposal is made for software development to facilitate dual-use data processing.
Echo sounding
Seabed
Shoal
Bathymetric chart
Cite
Citations (15)
The bathymetry mapping using underwater acoustic technology very important in Indonesia waters. Bathymetry is the result of measuring the height of the seabed so that the bathymetric map provides information about the seabed, where this information can provide benefits to several fields related to the seabed. In bathymetry mapping uses underwater acoustic technology where among them is using Single beam echosounder and MBES (Multibeam Echosounder System), and multibeam echosounder (MBES) is acoustic equipment that is intensively used frequently in basic waters mapping. The advantage of using underwater acoustic technology is the acquisition and processing of data in real time, high accuracy and precision (correction of the bathymetry data was carried out with reference to the 2008 International Hydrographic Organization (IHO), and cannot be a threat or damage to objects. Retrieval of bathymetry data must use parallel patterns, namely: patterns with perpendicular sounding directions and tend to be parallel to longitudinal lines or in accordance with parallel sounding patterns.
Echo sounding
Seabed
Hydrographic survey
Cite
Citations (4)
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.
Echo sounding
Seabed
Cite
Citations (7)
As part of an effort to evaluate the use of a forward looking sonar in autonomous underwater vehicles (AUVs) for navigation purposes, a study was performed using a commercially available off the shelf (COTS) multibeam echo sounder (MBES) operating in a forward looking mode to survey several sites in Narragansett Bay, Rhode Island. The forward looking bathymetric information acquired will aid in the improvement of navigation technologies for AUVs. This gaper describes the results of a survey performed using a MBES mounted at two negative elevation angles in the forward looking direction. The results from the bathymetric data acquired from these angles was found to be directly be correlated to the ground truth data. The sonar configuration, data collection, and data analysis schemes are discussed. Results from several survey sites are presented.
Echo sounding
Echo (communications protocol)
Elevation (ballistics)
Cite
Citations (0)
Echo sounding
Bathymetric chart
Echo (communications protocol)
Cite
Citations (45)
본 논문은 효율적인 저수지 수심측량 및 지층탐사를 위하여 음파탐지 기법을 이용한 수심측량과 지층탐사의 활용에 관한 것으로서 음향 측심기 (Echo Sounder) 및 고주파 지층탐사 장비 (Subbottom Profiler)를 이용하여 수원시 원천저수지에 대한 수심측량과 지층탐사를 수행하였다. 연구에 사용된 음향 측심기 및 고주파 지층탐사 장비는 GPS와 연결하여 선박에 설치하고 DGPS 측량 방법을 이용하여 평면위치, 수심 및 지층탐사 데이터를 동시에 취득하였다. 음향 측심기 및 고주파 지층탐사 장비를 통해 취득된 데이터는 GIS 프로그램을 이용하여 다양하게 분석함으로써 저수지의 수심 지형 저수량에 대한 결과와 저수지 침전물의 종류, 양, 두께, 분포 등에 대한 결과를 얻을 수 있었다. 이러한 데이터들과 분석 결과는 향후 저수지, 호수 및 댐 유역에 대한 장기적인 개발 관리계획을 위하여 음파탐지 기법을 이용한 다양한 관측장비를 활용하는데 다양한 정보들을 제공할 수 있을 것이다. This study incorporate hydroacoustic sampling for bathymetry and sediment survey in Won Cheon reservoir, Suwon city, Korea. Bathymetric and sedimentation surveys were conducted using a echo sounder system and subbottom profiler in the reservoirs. Data were collected using echo sounder systems and subbottom profiler linked to a GPS, to maximize data accuracy and vessel use, and geo-referenced using a DGPS enabling the acoustic data to be used in a GIS. Echo sounder and subbottom survey data were merged within geographic information system(GIS) software to provide detailed visualization and analyses of current depths, pre-impoundment topography, distribution, thickness, and volume estimates of lacustrine sediment, and water storage capacity. These data and analyses are, necessary for development of long term management plans for these reservoirs and their watersheds.
Echo sounding
Cite
Citations (8)
Echo sounding
Underwater Acoustics
Sonar signal processing
Beam pattern
Cite
Citations (0)