Journal articles: 'Bathymetric surveying'

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Tang, Kelvin Kang Wee, and Mohd Razali Mahmud. "The Accuracy of Satellite Derived Bathymetry in Coastal and Shallow Water Zone." International Journal of Built Environment and Sustainability 8, no. 3 (August 30, 2021): 1–8. http://dx.doi.org/10.11113/ijbes.v8.n3.681.

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Precise and accurate bathymetric measurements are conventionally acquired by means of ship-based acoustic equipment. Nevertheless, recent multispectral satellite imagery has been utilised as a substitute source to map the seabed topography which indicates new revolution in hydrographic surveying. This study assesses the satellite bathymetric depth’s accuracy based on the vertical uncertainty as stated in the Standards for Hydrographic Surveys issued by the International Hydrographic Organization. Two empirical algorithms, namely, Dierssen’s and Stumpf’s approaches have been adopted to model the seafloor topography over the coastal and shallow water at Tanjung Kupang, Malaysia. The outcomes demonstrate a decent correlation between the derived water depths and the sounding values acquired from a ship-based acoustic survey. For instance, a total of 1,215 out of the 1,367 generated water depths by Stumpf’s model have hit the minimum standard of survey in S-44. Similarly, out of the 1,367 samples from Diessen’s model, 1,211 samples have met the minimum requirement listed in the survey standard. The results demonstrate both imageries derived bathymetry models convey promising results which can be ultilised for bathymetric mapping application. Therefore, this imagery derived bathymetry can be considered as an alternative bathymetric surveying technique to supply cost-effective solution and survey data to support the Blue Economy and Sustainable Development Goals 14.

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Tang, K. K. W., M. R. Mahmud, A. Hussaini, and A. G. Abubakar. "EVALUATING IMAGERY-DERIVED BATHYMETRY OF SEABED TOPOGRAPHY TO SUPPORT MARINE CADASTRE." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-4/W16 (October 1, 2019): 633–39. http://dx.doi.org/10.5194/isprs-archives-xlii-4-w16-633-2019.

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Abstract. The Department of Survey and Mapping Malaysia has introduced marine cadastre system to register the rights, other valid interests therein and ownership of spatially determined parcels in the context of the marine environment yet the implementation of the system is still at the rudimentary stage. One of the big issues here is gathering land-to-seabed data to create a seamless topographic base map to support its marine cadastre project. Seabed bathymetric mapping in coastal zone is one of the major components to support marine cadastre. In the past, accurate bathymetric measurements can be a very laborious task in hydrographic surveying. Traditional vessel-based acoustic soundings require a lot of time, operation cost and others. Today, human’s ingenuity to yield bathymetric depths from multispectral images as an alternative source to chart the seabed topography has brought in new revolution to hydrography. The paper is initiated for evaluating water depth determination by using imagery-derived bathymetry technique and check its correlation with in-situ bathymetry depths. In the course of experiment, it demonstrates a good correlation between the imagery-derived bathymetric depths and the in-situ bathymetric depths, and majority of the derived depths have passed the minimum requirement of the IHO S-44 survey standard. The result also shows that these empirical models deliver promising outcome which can be use over the turbid environment setting. Hence, imagery-derived bathymetry approach can be an efficient and repeatable way to derive the seabed topography over a huge segment of coastal region. This study also suggests that imagery-derived bathymetry approach can be recognised as an aid in seabed topographic mapping to support marine cadastre initiative.

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Said, N. M., M. R. Mahmud, and R. C. Hasan. "SATELLITE-DERIVED BATHYMETRY: ACCURACY ASSESSMENT ON DEPTHS DERIVATION ALGORITHM FOR SHALLOW WATER AREA." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-4/W5 (October 5, 2017): 159–64. http://dx.doi.org/10.5194/isprs-archives-xlii-4-w5-159-2017.

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Over the years, the acquisition technique of bathymetric data has evolved from a shipborne platform to airborne and presently, utilising space-borne acquisition. The extensive development of remote sensing technology has brought in the new revolution to the hydrographic surveying. Satellite-Derived Bathymetry (SDB), a space-borne acquisition technique which derives bathymetric data from high-resolution multispectral satellite imagery for various purposes recently considered as a new promising technology in the hydrographic surveying industry. Inspiring by this latest developments, a comprehensive study was initiated by National Hydrographic Centre (NHC) and Universiti Teknologi Malaysia (UTM) to analyse SDB as a means for shallow water area acquisition. By adopting additional adjustment in calibration stage, a marginal improvement discovered on the outcomes from both Stumpf and Lyzenga algorithms where the RMSE values for the derived (predicted) depths were 1.432 meters and 1.728 meters respectively. This paper would deliberate in detail the findings from the study especially on the accuracy level and practicality of SDB over the tropical environmental setting in Malaysia.

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Duplančić Leder, Tea, Nenad Leder, and Josip Peroš. "Satellite Derived Bathymetry Survey Method - Example of Hramina Bay." Transactions on Maritime Science 8, no. 1 (April 20, 2019): 99–108. http://dx.doi.org/10.7225/toms.v08.n01.010.

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Satellite Derived Bathymetry (SDB) method uses satellite or other remote multispectral imagery for depth determination in very shallow coastal areas with clear waters. Commonly, SDB survey method can be used when planning hydrographic surveying of marine areas not surveyed or areas with old bathymetric data. This method has become widely used in the past few years. SDB is a survey method founded on analytical modelling of light penetration through the water column in visible and infrared bands. In this article, SDB method was applied by using free-of-charge Landsat 8 and Sentinel 2 satellite images to get the bathymetric data in the area of Hramina Bay in the Central Adriatic. SDB processing procedures and algorithms were described. Processed satellite data was uploaded on geodetic software and ENC S-57 format. The bathymetric map of Hramina Bay obtained by the SDB method was compared with the approach usage band Electronic Nautical Chart (ENC) HR400512 with satisfying positional and vertical accuracy.

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Halmai, Ákos, Alexandra Gradwohl–Valkay, Szabolcs Czigány, Johanna Ficsor, Zoltán Árpád Liptay, Kinga Kiss, Dénes Lóczy, and Ervin Pirkhoffer. "Applicability of a Recreational-Grade Interferometric Sonar for the Bathymetric Survey and Monitoring of the Drava River." ISPRS International Journal of Geo-Information 9, no. 3 (March 5, 2020): 149. http://dx.doi.org/10.3390/ijgi9030149.

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Sonar survey of shallow water bodies has challenged scientists for a long time. Although these water courses are small, still they have an increasing ecological, touristic and economical role. As maritime sonars are non-ideal tools for shallow waters, the bathymetric survey of these rivers has been taken with cross-sectional methods. Due to recent developments, interferometric surveying technology have also burst into the market of recreational-grade fish-finders. The objective of the current study was the development of a novel, complex and integrated surveying technique which is affordable, robust and applicable even at low water levels. A recreational-grade sonar system was assembled and mounted on a double-hull vessel and connected with a geodetic Global Navigation Satellite System (GNSS) device. We have developed a novel software which enables the bridging between a closed sonar file format and the commonly used Geographic Information System (GIS) datasets. As a result, the several month-long conventional bathymetric survey of the 146 km-long reach of the Drava River was reduced to 20 days and provided channel bathymetry of many orders of magnitude higher than the classical methods. Additionally, a large number of spatial derivatives were generated which enables the analysis of channel morphology, textural variation of channel sediments and the accurate delineation of navigational routes.

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Arndt, Jan Erik, Robert D. Larter, Peter Friedl, Karsten Gohl, and Kathrin Höppner. "Bathymetric controls on calving processes at Pine Island Glacier." Cryosphere 12, no. 6 (June 15, 2018): 2039–50. http://dx.doi.org/10.5194/tc-12-2039-2018.

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Abstract. Pine Island Glacier is the largest current Antarctic contributor to sea-level rise. Its ice loss has substantially increased over the last 25 years through thinning, acceleration and grounding line retreat. However, the calving line positions of the stabilising ice shelf did not show any trend within the observational record (last 70 years) until calving in 2015 led to unprecedented retreat and changed the alignment of the calving front. Bathymetric surveying revealed a ridge below the former ice shelf and two shallower highs to the north. Satellite imagery shows that ice contact on the ridge was likely lost in 2006 but was followed by intermittent contact resulting in back stress fluctuations on the ice shelf. Continuing ice-shelf flow also led to occasional ice-shelf contact with the northern bathymetric highs, which initiated rift formation that led to calving. The observations show that bathymetry is an important factor in initiating calving events.

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Work, Paul A., Mark Hansen, and W. Erick Rogers. "Bathymetric Surveying with GPS and Heave, Pitch, and Roll Compensation." Journal of Surveying Engineering 124, no. 2 (May 1998): 73–90. http://dx.doi.org/10.1061/(asce)0733-9453(1998)124:2(73).

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Agrafiotis, Panagiotis, Dimitrios Skarlatos, Andreas Georgopoulos, and Konstantinos Karantzalos. "DepthLearn: Learning to Correct the Refraction on Point Clouds Derived from Aerial Imagery for Accurate Dense Shallow Water Bathymetry Based on SVMs-Fusion with LiDAR Point Clouds." Remote Sensing 11, no. 19 (September 24, 2019): 2225. http://dx.doi.org/10.3390/rs11192225.

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The determination of accurate bathymetric information is a key element for near offshore activities; hydrological studies, such as coastal engineering applications, sedimentary processes, hydrographic surveying, archaeological mapping and biological research. Through structure from motion (SfM) and multi-view-stereo (MVS) techniques, aerial imagery can provide a low-cost alternative compared to bathymetric LiDAR (Light Detection and Ranging) surveys, as it offers additional important visual information and higher spatial resolution. Nevertheless, water refraction poses significant challenges on depth determination. Till now, this problem has been addressed through customized image-based refraction correction algorithms or by modifying the collinearity equation. In this article, in order to overcome the water refraction errors in a massive and accurate way, we employ machine learning tools, which are able to learn the systematic underestimation of the estimated depths. In particular, an SVR (support vector regression) model was developed, based on known depth observations from bathymetric LiDAR surveys, which is able to accurately recover bathymetry from point clouds derived from SfM-MVS procedures. Experimental results and validation were based on datasets derived from different test-sites, and demonstrated the high potential of our approach. Moreover, we exploited the fusion of LiDAR and image-based point clouds towards addressing challenges of both modalities in problematic areas.

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Levin, E., G. Meadows, R. Shults, U. Karacelebi, and H. S. Kulunk. "BATHYMETRIC SURVEYING IN LAKE SUPERIOR: 3D MODELING AND SONAR EQUIPMENTS COMPARING." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W10 (April 17, 2019): 101–6. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w10-101-2019.

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Abstract. This paper represents the overview of hydrographic surveying and different types of modern and traditional surveying equipment, and data acquisition using the traditional single beam sonar system and a modern fully autonomous underwater vehicle (AUV) IVER3. During the study, the data sets were collected using the vehicles of the Great Lake Research Center at Michigan Technological University. This paper presents how to process and edit the bathymetric data on SonarWiz5. Lastly, it compares the accuracy of the two different sonar systems in the different missions and creates 3D models to display and understand the elevations changes. Moreover, the 3D models were created after importing the data sets in the same coordinate system. In this study, the data sets were recorded by two different sensors in the two study locations in the Keweenaw Waterway in Michigan, U.S. between the cities of Houghton and Hancock. The first one equipment is the Lowrance HDS-7 sonar on the surveying boat, and other one is the EdgeTech 2205 sonar on the fully AUV of IVER3. One of the purposes of this study is to explore the sonar post processing programs, which are very important to interpret sonar and bathymetric data, and obtained the same coordinate system of the study areas. During the project, three main processing programs were used. The first one is UnderSee Explorer 2.6, which has been used to process the data sets of Polar SV boat. Secondly, EdgeTech Discover 4600 bathymetric software used EdgeTech 2205 sonar data sets to create bathymetric files that were used in SonarWiz5. Lastly, SonarWiz5 sonar processing software can be used to process the data sets. After the data acquisition and the data process, six profiles from the first study area and the five profiles from the second study are created to compare the data sets and elevations difference. It is shown that single beam sonar might miss some details, such as pipeline and quick elevation changes on seabed when we compare to the side scan sonar of IVER3 because the single side scan sonar can acquire better resolutions to understand the 3D features, such as pipelines, reliefs etc.

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Blakey, Andrew, Eugenia Acosta, and Ryan Gariepy. "A Field Comparison of Methods and Data Results Between a Manual And Robotic Remote Sensed Survey of a Storm Water Management Pond in Kitchener, Ontario." GEOMATICA 68, no. 4 (December 2014): 345–54. http://dx.doi.org/10.5623/cig2014-408.

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Conventional shallow water bathymetric survey methods are time consuming, expensive, susceptible to human error, and often hazardous. An innovative end-to-end solution that improves water surveying by reduc ing these risks through the use of an unmanned bathymetric data collection system has been designed and built. This system combines a collection of pre- and post-processing routines with the capabilities of a purposebuilt unmanned surface vessel to measure and build accurate bathymetric datasets that are easy to integrate into any CAD or GIS database. Data collection involves the fusion of high-accuracy data from a single beam echosounder, GPS, and iner tial measurement unit (IMU) to generate sediment surface points at centimetre-level accuracy. Through use of an unmanned vessel, these surveys are repeatable without requiring any persons to be on or in the waterbody. This paper presents the results of a focused validation study conducted to illustrate that this platform gen er ates comparable data to a manual survey while greatly reducing survey time and improving safety. Results show a volumetric difference of 2.8% between the Kingfisher USV and manual survey data. Surveying duration was shorter at 42 minutes compared to 140 minutes. This survey was also reliably completed despite challenging environmental conditions.

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Arseni, Voiculescu, Georgescu, Iticescu, and Rosu. "Testing Different Interpolation Methods Based on Single Beam Echosounder River Surveying. Case Study: Siret River." ISPRS International Journal of Geo-Information 8, no. 11 (November 10, 2019): 507. http://dx.doi.org/10.3390/ijgi8110507.

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Bathymetric measurements play an important role in assessing the sedimentation rate, deposition of pollutants, erosion rate, or monitoring of morphological changes in a river, lake, or accumulation basin. In order to create a coherent and continuous digital elevation model (DEM) of a river bed, various data interpolation methods are used, especially when single-beam bathymetric measurements do not cover the entire area and when there are areas which are not measured. Interpolation methods are based on numerical models applied to natural landscapes (e.g., meandering river) by taking into account various morphometric and morphologies and a wide range of scales. Obviously, each interpolation method, used in standard or customised form, yields different results. This study aims at testing four interpolation methods in order to determine the most appropriate method which will give an accurate description of the riverbed, based on single-beam bathymetric measurements. The four interpolation methods selected in the present research are: inverse distance weighting (IDW), radial basis function (RBF) with completely regularized spline (CRS) which uses deterministic interpolation, simple kriging (KRG) which is a geo-statistical method, and Topo to Raster (TopoR), a particular method specifically designed for creating continuous surfaces from various elevation points, contour, or polygon data, suitable for creating surfaces for hydrologic analysis. Digital elevation models (DEM’s) were statistically analyzed and precision and errors were evaluated. The single-beam bathymetric measurements were made on the Siret River, between 0 and 35 km. To check and validate the methods, the experiment was repeated for five randomly selected cross-sections in a 1500 m section of the river. The results were then compared with the data extracted from each elevation model generated with each of the four interpolation methods. Our results show that: 1) TopoR is the most accurate technique, and 2) the two deterministic methods give large errors in bank areas, for the entire river channel and for the particular cross-sections.

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Xanthakis, Michail, Kosmas Pavlopoulos, Vasilios Kapsimalis, Georgios Apostolopoulos, Gavriil Xanthopoulos, Panagiotis Stefanidis, and Niki Evelpidou. "Prediction of Soil Loss in a Reservoir Watershed Using an Erosion Model and Modern Technological Tools: A Case Study of Marathon Lake, Attica in Greece." Environmental Sciences Proceedings 2, no. 1 (September 7, 2020): 63. http://dx.doi.org/10.3390/environsciproc2020002063.

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Marathon Lake is an artificial reservoir with great environmental, ecological, social, and economic significance because it was the main source of water for Athens, the capital of Greece, for many years. The present study details the first attempt to map sedimentation in Marathon Lake in detail, using bathymetric mapping and soil erosion field surveying of the torrent watershed areas. First, the results of a bathymetric survey carried out in 2011 were compared with topographic maps that pre-date the construction of the dam. Based on this comparison, an estimated 8.34 hm3 of sediment have been deposited in the 80 years since the dam’s construction. In the current survey, the Revised Universal Soil Loss Equation (RUSLE) was used to estimate soil loss in the watershed area of the streams that end in Marathon Lake. The estimated value from the RUSLE was substantially lower (3.02 hm3) than that calculated in the bathymetric survey.

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Rossi, Lorenzo, Irene Mammi, and Filippo Pelliccia. "UAV-Derived Multispectral Bathymetry." Remote Sensing 12, no. 23 (November 27, 2020): 3897. http://dx.doi.org/10.3390/rs12233897.

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Bathymetry is considered an important component in marine applications as several coastal erosion monitoring and engineering projects are carried out in this field. It is traditionally acquired via shipboard echo sounding, but nowadays, multispectral satellite imagery is also commonly applied using different remote sensing-based algorithms. Satellite-Derived Bathymetry (SDB) relates the surface reflectance of shallow coastal waters to the depth of the water column. The present study shows the results of the application of Stumpf and Lyzenga algorithms to derive the bathymetry for a small area using an Unmanned Aerial Vehicle (UAV), also known as a drone, equipped with a multispectral camera acquiring images in the same WorldView-2 satellite sensor spectral bands. A hydrographic Multibeam Echosounder survey was performed in the same period in order to validate the method’s results and accuracy. The study area was approximately 0.5 km2 and located in Tuscany (Italy). Because of the high percentage of water in the images, a new methodology was also implemented for producing a georeferenced orthophoto mosaic. UAV multispectral images were processed to retrieve bathymetric data for testing different band combinations and evaluating the accuracy as a function of the density and quantity of sea bottom control points. Our results indicate that UAV-Derived Bathymetry (UDB) permits an accuracy of about 20 cm to be obtained in bathymetric mapping in shallow waters, minimizing operative expenses and giving the possibility to program a coastal monitoring surveying activity. The full sea bottom coverage obtained using this methodology permits detailed Digital Elevation Models (DEMs) comparable to a Multibeam Echosounder survey, and can also be applied in very shallow waters, where the traditional hydrographic approach requires hard fieldwork and presents operational limits.

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Alvarez, Laura, Hernan Moreno, Antonio Segales, Tri Pham, Elizabeth Pillar-Little, and Phillip Chilson. "Merging Unmanned Aerial Systems (UAS) Imagery and Echo Soundings with an Adaptive Sampling Technique for Bathymetric Surveys." Remote Sensing 10, no. 9 (August 28, 2018): 1362. http://dx.doi.org/10.3390/rs10091362.

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Bathymetric surveying to gather information about depths and underwater terrain is increasingly important to the sciences of hydrology and geomorphology. Submerged terrain change detection, water level, and reservoir storage monitoring demand extensive bathymetric data. Despite often being scarce or unavailable, this information is fundamental to hydrodynamic modeling for imposing boundary conditions and building computational domains. In this manuscript, a novel, low-cost, rapid, and accurate method is developed to measure submerged topography, as an alternative to conventional approaches that require significant economic investments and human power. The method integrates two types of Unmanned Aerial Systems (UAS) sampling techniques. The first couples a small UAS (sUAS) to an echosounder attached to a miniaturized boat for surveying submerged topography in deeper water within the range of accuracy. The second uses Structure from Motion (SfM) photogrammetry to cover shallower water areas no detected by the echosounder where the bed is visible from the sUAS. The refraction of light passing through air–water interface is considered for improving the bathymetric results. A zonal adaptive sampling algorithm is developed and applied to the echosounder data to densify measurements where the standard deviation of clustered points is high. This method is tested at a small reservoir in the U.S. southern plains. Ground Control Points (GCPs) and checkpoints surveyed with a total station are used for properly georeferencing of the SfM photogrammetry and assessment of the UAS imagery accuracy. An independent validation procedure providing a number of skill and error metrics is conducted using ground-truth data collected with a leveling rod at co-located reservoir points. Assessment of the results shows a strong correlation between the echosounder, SfM measurements and the field observations. The final product is a hybrid bathymetric survey resulting from the merging of SfM photogrammetry and echosoundings within an adaptive sampling framework.

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Clayton, Lena, and Glen Dennison. "Inexpensive Video Drop-camera for Surveying Sensitive Benthic Habitats: Applications from Glass Sponge (Hexactinellida) Reefs in Howe Sound, British Columbia." Canadian Field-Naturalist 131, no. 1 (July 14, 2017): 46–54. http://dx.doi.org/10.22621/cfn.v131i1.1783.

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Where marine waters are shallow and bathymetric features are steep, the typically employed multi-beam side scan sonar is not always reliable for identifying complex biological structures. Here, we present a cost-efficient method used in Howe Sound, British Columbia, for bathymetric mapping, exploration, and ground-truthing of glass sponge bioherms. A simple depth sounder and software package was used to produce bathymetric maps. From these maps, prospective sites were selected and surveyed to investigate bioherm presence with a simple drop-camera towed off the bow of a small drifting vessel during calm seas. This method was used during a 4-year citizen science initiative that led to the discovery of 12 glass sponge bioherms in Howe Sound, the first step in protecting these globally unique reefs from the impact of bottom-contact fishing, anchoring, and potential industrial contamination. Before our work using this method, only two glass sponge bioherms had been identified in Howe Sound. The method also proved effective as a means to quantify damage to bioherms from fishing gear.

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Gutberlet, Manfred, and Hans Werner Schenke. "Hydrosweep: New era in high precision bathymetric surveying in deep and shallow water." Marine Geodesy 13, no. 1 (January 1989): 1–23. http://dx.doi.org/10.1080/15210608909379602.

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Karczmarz, Dariusz, Przemysław Mądrzycki, Henryk Szkudlarz, Wojciech Puchalski, Joanna Gorczyca, Marcin Ciepliński, Tomasz Falkowski, and Piotr Ostrowski. "Evaluation of the possibilities to use imagery reconnaissance sensors to identify the geological-engineering conditions in lowland river channels." Journal of KONBiN 48, no. 1 (December 1, 2018): 169–89. http://dx.doi.org/10.2478/jok-2018-0052.

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Abstract The article concerns the issue of using imagery reconnaissance sensors for the identification of geological-engineering conditions in river channels, in the aspect of evaluating the forcing of a water obstacle. It discusses the issues associated with using air platforms (manned and unmanned) in remote sensing surveying of selected fragments of the Vistula and Bug river channels and the correct interpretation of the obtained results, through their verification using bathymetric tests conducted directly in the river channels.

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Borowiak, Dariusz, Kamil Nowiński, and Katarzyna Grabowska. "A new bathymetric survey of the Suwałki Landscape Park lakes." Limnological Review 16, no. 4 (December 1, 2016): 185–97. http://dx.doi.org/10.1515/limre-2016-0020.

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Abstract The results of the latest bathymetric survey of 21 lakes in the Suwałki Landscape Park (SLP) are presented here. Measurements of the underwater lake topography were carried out in the years 2012–2013 using the hydroacoustic method (sonar Lawrence 480M). In the case of four lakes (Błędne, Pogorzałek, Purwin, Wodziłki) this was the first time a bathymetric survey had been performed. Field material was used to prepare bathymetric maps, which were then used for calculating the basic size and shape parameters of the lake basins. The results of the studies are shown against the nearly 90 year history of bathymetric surveying of the SLP lakes. In the light of the current measurements, the total area of the SLP lakes is over 634 hm2 and its limnic ratio is 10%. Lake water resources in the park were estimated at 143 037.1 dam3. This value corresponds to a retention index of 2257 mm. In addition, studies have shown that the previous morphometric data are not very accurate. The relative differences in the lake surface areas ranged from –14.1 to 9.1%, and in the case of volume – from –32.2 to 35.3%. The greatest differences in the volume, expressed in absolute values, were found in the largest SLP lakes: Hańcza (1716.1 dam3), Szurpiły (1282.0 dam3), Jaczno (816.4 dam3), Perty (427.1 dam3), Jegłówek (391.2 dam3) and Kojle (286.2 dam3). The smallest disparities were observed with respect to the data obtained by the IRS (Inland Fisheries Institute in Olsztyn). The IMGW (Institute of Meteorology and Water Management) bathymetric measurements were affected by some significant errors, and morphometric parameters determined on their basis are only approximate.

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Alevizos, Evangelos. "A Combined Machine Learning and Residual Analysis Approach for Improved Retrieval of Shallow Bathymetry from Hyperspectral Imagery and Sparse Ground Truth Data." Remote Sensing 12, no. 21 (October 23, 2020): 3489. http://dx.doi.org/10.3390/rs12213489.

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Mapping shallow bathymetry by means of optical remote sensing has been a challenging task of growing interest in recent years. Particularly, many studies exploit earlier empirical models together with the latest multispectral satellite imagery (e.g., Sentinel 2, Landsat 8). However, in these studies, the accuracy of resulting bathymetry is (a) limited for deeper waters (>15 m) and/or (b) is being influenced by seafloor type albedo. This study explores further the capabilities of hyperspectral satellite imagery (Hyperion), which provides several spectral bands in the visible spectrum, along with existing reference bathymetry. Bathymetry predictors are created by applying the semi-empirical approach of band ratios on hyperspectral imagery. Then, these predictors are fed to machine learning regression algorithms for predicting bathymetry. Algorithm performance is being further compared to bathymetry predictions from multiple linear regression analysis. Following the initial predictions, the residual bathymetry values are interpolated by applying the Ordinary Kriging method. Then, the predicted bathymetry from all three algorithms along with their associated residual grids is used as predictors at a second processing stage. Validation results show that by using a second stage of processing, the root-mean-square error values of predicted bathymetry is being improved by ≈1 m even for deeper water (up to 25 m). It is suggested that this approach is suitable for (a) contributing wide-scale, high-resolution shallow bathymetry toward the goals of the Seabed 2030 program and (b) as a coarse resolution alternative to effort-consuming single-beam sonar or costly airborne bathymetric laser surveying.

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Dove, Isabel A., Amy Leventer, Meredith J. Metcalf, Stefanie A. Brachfeld, Robert B. Dunbar, Patricia Manley, Amelia E. Shevenell, et al. "Marine geological investigation of Edward VIII Gulf, Kemp Coast, East Antarctica." Antarctic Science 32, no. 3 (March 4, 2020): 210–22. http://dx.doi.org/10.1017/s0954102020000097.

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AbstractA physical oceanographic, geophysical and marine geological survey of Edward VIII Gulf, Kemp Coast, collected data from conductivity–temperature–depth casts, multi-beam bathymetric swath mapping and 3.5 kHz sub-bottom surveying. Modified circumpolar deep water (mCDW) is observed in Edward VIII Gulf, as well as notable bathymetric features including mega-scale glacial lineations and a 1750 m-deep trough. Sedimentological, geochemical, rock-magnetic and micropalaeontological analysis of two kasten cores document regional palaeoclimate and palaeo-oceanographic conditions over the past 8000 years, with a warm period occurring from c. 8 to 4 ka and a shift to cooler conditions beginning at c. 4 ka and persisting until at least 0.9 ka. Sediment packages > 40 m thick within deep troughs in Edward VIII Gulf present potential targets for higher-resolution Holocene and deglacial climate studies. Despite the presence of mCDW on the shelf, inland bed topography consisting of highland terrain suggests the likelihood of relative stability of this sector of the East Antarctic Ice Sheet.

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Lopes, José Wellington Batista, and José Carlos de Araújo. "Simplified Method for the Assessment of Siltation in Semiarid Reservoirs Using Satellite Imagery." Water 11, no. 5 (May 13, 2019): 998. http://dx.doi.org/10.3390/w11050998.

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The Brazilian semiarid region strongly depends on superficial reservoirs (one every 5 km 2 ) and hence is subject to the deleterious effects of siltation, which reduces water availability. This research proposed a method, simplified bathymetric surveying using remote sensing, for updating the morphological parameters of reservoirs. The study area was the Pentecoste reservoir (360 hm 3 ) in northeastern Brazil. The results were compared to the conventional bathymetric survey method, which demands more sampling points (235 compared to 1) and was assumed as reference. Siltation assessed through the proposed method was nearly twice as high as that observed through conventional surveys. The morphological parameters derived by both methods were used to assess the long-term water balance of the reservoir. The results show that the outflow diverged 30%, while the evaporated discharge and water availability diverged 10% between the methods. Therefore, in the conditions of the Brazilian semiarid region, the simplified method suffices to assess the water availability of reservoirs affected by silting.

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Silva, Sérgio Rui, Sérgio Cunha, Aníbal Matos, and Nuno Cruz. "Shallow Water Surveying Using Experimental Interferometric Synthetic Aperture Sonar." Marine Technology Society Journal 43, no. 1 (March 1, 2009): 50–63. http://dx.doi.org/10.4031/mtsj.43.1.4.

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AbstractThis paper describes an interferometric synthetic aperture sonar system based on an unmanned surface vehicle customized for shallow water environments. Synthetic aperture sonar enables imagery of high resolution that is independent of range by using the displacement of the sonar platform to create a large virtual array. If two geometrically displaced images are obtained, the construction of three-dimensional topographic maps is possible through the use of interferometric techniques. The use of an unmanned surface vehicle presents several advantages that alleviate some problems related to the formation of synthetic aperture images, which are mainly related to the fact that a precise navigation system can be used for the boat control and sonar imagery motion compensation. Also, a small unmanned surface vehicle is advantageous in terms of cost of operation, maintenance and ease of deployment. Mapping of shallow water areas is an important task for many commercial and scientific applications like river navigability, infrastructure maintenance and natural resource monitoring. These tasks can be done efficiently with this system. Sample data obtained during test trials illustrate how synthetic aperture can be used to generate underwater imagery and bathymetric data.

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Purdie, Heather, Paul Bealing, Emily Tidey, Christopher Gomez, and Justin Harrison. "Bathymetric evolution of Tasman Glacier terminal lake, New Zealand, as determined by remote surveying techniques." Global and Planetary Change 147 (December 2016): 1–11. http://dx.doi.org/10.1016/j.gloplacha.2016.10.010.

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Eisemann, Eve, Lauren Dunkin, Michael Hartman, and Jennifer Wozencraft. "POST-HURRICANE COASTAL MAPPING AND CHANGE ANALYSIS: NATIONAL COASTAL MAPPING PROGRAM." Coastal Engineering Proceedings, no. 36 (December 30, 2018): 84. http://dx.doi.org/10.9753/icce.v36.risk.84.

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Hurricane and other extreme storm impacts pose one of the greatest threats to coastal environments, populations, and infrastructure. The U.S. Army Corps of Engineers (USACE) National Coastal Mapping Program (NCMP), executed by the Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX), collects and processes high resolution aerial imagery and lidar data that provide regional datasets to support assessments of coastal change. The NCMP surveying methods and data products are invaluable tools for coastal management and have the potential to produce rapid-response data following extreme storm impacts. Emergency post-storm deployment of this system was used following Hurricane Matthewâ€™s impact in October 2016 where the NCMP surveyed from Key Biscayne, FL to the VA/MD border between October 27th and December 2nd, collecting topographic and bathymetric lidar along the coast in a 1.5 km swath. Approximately one year later, Hurricane Irma impacted the Florida east and west coast in September 2017. The NCMP surveyed the entire Florida east coast, including the Keys, in addition to Collier County on the West Coast of Florida from September 22 to October 25.

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Moisan, E., C. Heinkele, P. Charbonnier, P. Foucher, P. Grussenmeyer, S. Guillemin, and M. Koehl. "DYNAMIC 3D MODELING OF A CANAL-TUNNEL USING PHOTOGRAMMETRIC AND BATHYMETRIC DATA." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W3 (February 23, 2017): 495–501. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w3-495-2017.

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This contribution introduces an original method for dynamically surveying the vault and underwater parts of a canal-tunnel for 3D modeling. The recording system, embedded on a barge, is composed of cameras that provide images of the above-water part of the tunnel, and a sonar that acquires underwater 3D profiles. In this contribution we propose to fully exploit the capacities of photogrammetry to deal with the issue of geo-referencing data in the absence of global positioning system (GPS) data. More specifically, we use it both for reconstructing the vault and side walls of the tunnel in 3D and for estimating the trajectory of the boat, which is necessary to rearrange sonar profiles to form the 3D model of the canal. We report on a first experimentation carried out inside a canal-tunnel and show promising preliminary results that illustrate the potentialities of the proposed approach.

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Raygosa-Barahona, Rubén, Miguel Ángel Garcia-Terán, Cecilia Enriquez, and Ernesto Olguín-Díaz. "Experimental Evaluation of an Autonomous Surface Craft for Shallow-Water Bathymetry." Marine Technology Society Journal 51, no. 4 (July 1, 2017): 59–67. http://dx.doi.org/10.4031/mtsj.51.4.7.

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AbstractVast coastal water bodies such as mangroves and wetlands, despite their enormous importance, are inaccessible to even the smallest aquatic vehicles, which are not capable of navigating the extremely shallow environments. To understand their behavior and the transport and exchange processes with both sea and land, it is crucial to study local hydrodynamics, which are highly dependent on bathymetric configuration. In order to obtain accurate and high spatial resolution bathymetric samples, an existing small surface vehicle instrumented with GPS and echosounder was implemented with an autopilot system to achieve autonomy. A description of the autonomous system together with the evaluation of the whole vehicle's performance in a natural coastal environment (e.g., affected by the wind, waves, and currents that exist in coastal regions) is presented. The navigation system is based on an autopilot system, which follows a set of user-selected waypoints to drive the vehicle through a previously designed path. The trajectory is self-corrected to achieve sufficient accuracy (the limits are also defined by the user) using real-time kinematics. The tracking is performed by two independent proportional-integral-derivative (PID) control systems: the boat's displacement speed and the bearing control. A simple experimental procedure to tune the low-level PID control parameters is presented. Comparisons between the bathymetric maps obtained with the system and with other standard bathymetric surveys from a selected coastal site (ship-towed echosounder) are presented to test both the precision of the boat's navigation and the fine structure of the bottom topography. The results confirm the system's capability as a valuable tool for surveying large and very shallow environments.

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Agrafiotis, P., D. Skarlatos, A. Georgopoulos, and K. Karantzalos. "SHALLOW WATER BATHYMETRY MAPPING FROM UAV IMAGERY BASED ON MACHINE LEARNING." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W10 (April 17, 2019): 9–16. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w10-9-2019.

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Abstract. The determination of accurate bathymetric information is a key element for near offshore activities, hydrological studies such as coastal engineering applications, sedimentary processes, hydrographic surveying as well as archaeological mapping and biological research. UAV imagery processed with Structure from Motion (SfM) and Multi View Stereo (MVS) techniques can provide a low-cost alternative to established shallow seabed mapping techniques offering as well the important visual information. Nevertheless, water refraction poses significant challenges on depth determination. Till now, this problem has been addressed through customized image-based refraction correction algorithms or by modifying the collinearity equation. In this paper, in order to overcome the water refraction errors, we employ machine learning tools that are able to learn the systematic underestimation of the estimated depths. In the proposed approach, based on known depth observations from bathymetric LiDAR surveys, an SVR model was developed able to estimate more accurately the real depths of point clouds derived from SfM-MVS procedures. Experimental results over two test sites along with the performed quantitative validation indicated the high potential of the developed approach.

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Naus, Marchel, Szymak, and Nowak. "Assessment of the Accuracy of Determining the Angular Position of the Unmanned Bathymetric Surveying Vehicle Based on the Sea Horizon Image." Sensors 19, no. 21 (October 25, 2019): 4644. http://dx.doi.org/10.3390/s19214644.

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The paper presents the results of research on assessing the accuracy of angular position measurement relative to the sea horizon using a camera mounted on an unmanned bathymetric surveying vehicle of the Unmanned Surface Vehicle (USV) or Unmanned Aerial Vehicle (UAV) type. The first part of the article presents the essence of the problem. The rules of taking the angular position of the vehicle into account in bathymetric surveys and the general concept of the two-camera tilt compensator were described. The second part presents a mathematical description of the meters characterizing a resolution and a mean error of measurements, made on the base of the horizon line image, recorded with an optical system with a Complementary Metal-Oxide Semiconductor (CMOS) matrix. The phenomenon of the horizon line curvature in the image projected onto the matrix that appears with the increase of the camera height has been characterized. The third part contains an example of a detailed analysis of selected cameras mounted on UAVs manufactured by DJI, carried out using the proposed meters. The obtained results including measurement resolutions of a single-pixel and mean errors of the horizon line slope measurement were presented in the form of many tables and charts with extensive comments. The final part presents the general conclusions from the performed research and a proposal of directions for their further development.

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Pacina, Jan, Zuzana Lenďáková, Jiří Štojdl, Tomáš Matys Grygar, and Martin Dolejš. "Dynamics of Sediments in Reservoir Inflows: A Case Study of the Skalka and Nechranice Reservoirs, Czech Republic." ISPRS International Journal of Geo-Information 9, no. 4 (April 18, 2020): 258. http://dx.doi.org/10.3390/ijgi9040258.

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A wide variety of geographic information system tools and methods was used for pre-dam topography reconstruction and reservoir bottom surveying in two dam reservoirs in the Ohře River, Czech Republic. The pre-dam topography was reconstructed based on archival aerial imagery and old maps. The benefits and drawbacks of these methods were tested and explained with emphasis on the fact that not all processed archival data are suitable for pre-dam topography modeling. Bathymetric surveying of a reservoir bottom is presently routine, but in this study, we used a wide combination of bathymetric mapping methods (sonar, ground penetration radar, and sub-bottom profiler) and topographic survey tools (LiDAR and photogrammetry), bringing great benefits for bottom dynamic analysis and data cross-validation. The data that we gathered made it possible to evaluate the formation of the inflow deltas in the reservoirs studied and assess the sediment reworking during recent seasonal drawdowns. A typical inflow delta was formed in the deeper of the two studied reservoirs, while the summer 2019 drawdown caused the formation and incision of a temporary drawdown channel and erosive downstream transport of approximately 1/10 of the delta body thickness in approximately 1/10 of the delta transverse size. No inflow delta was formed in the shallower of the studied reservoirs, but unexpectedly extensive sediment reworking was observed in the inflow part of the reservoir. Both the studied reservoirs and the pre-dam river floodplain have accumulated historical contamination by risk elements such as As, Hg, Pb; thus, the enhanced erosion of existing sediment bodies expected in the future, owing to more frequent droughts and global climate change, will endanger the ecological quality of the water and solids outflowing from the reservoirs.

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Strupler, M., F. S. Anselmetti, M. Hilbe, and M. Strasser. "Quantitative characterization of subaqueous landslides in Lake Zurich (Switzerland) based on a high-resolution bathymetric dataset." Geological Society, London, Special Publications 477, no. 1 (March 6, 2018): 399–412. http://dx.doi.org/10.1144/sp477.7.

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AbstractNew high-resolution surveying techniques allow subaqueous geomorphology to be investigated in great detail. Such analyses are important as the morphologies are often indicative of past processes, including mass movements. For peri-alpine Lake Zurich, many mass-wasting events have occurred in the past millennia. While the ages of these events are known from past studies on the respective deposits in the lake basin, the surface expressions and distribution of the respective features on the slopes have not been extensively described. Here we quantitatively characterize the morphologic features on the entire lake floor. A total of 50 subaqueous landslides are morphologically identified in a high-resolution digital bathymetric model (DBM), mapped and characterized using a geographic information system (GIS). Many slides show relatively small erosion areas (<0.05 km2) and are located in shallow water (<10 m water depth). The roughness of the individual landslide-translation areas is quantified using the standard deviation of a measure called bathymetric position index (BPI) and related to the slides ages. The DBM allows the detection of traces of mass-movements dating back to c. 5000 cal years BP. Our results demonstrate that morphometric analyses on a high-resolution DBM can contribute to a better understanding of sublacustrine mass movements.

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Dmitrevskiy, N. N., and R. A. Ananyev. "Engineering geophysical studies in the Black Sea from onboard the R/V Ashamba during 2017." Океанология 59, no. 2 (June 9, 2019): 319–20. http://dx.doi.org/10.31857/s0030-1574592319-320.

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In May and October 2017, expeditionary research was carried out in the area of Gelendzhik in the Black Sea at the R/V «Ashamba». The main tasks were the mapping of the seabed and the search for small-sized objects at the bottom of the water area using a WASSP WMB-3250 multibeam echo sounder. Surveys included areal surveying and drawing up bathymetric maps of test sites in Gelendzhik Bay and in the transition zone from the shelf to the continental slope. In addition, the echo sounder was used to search and determine the exact coordinates of the bottom seismograph installed at the seabed near the Divnomorskoye village in May 2016. The article presents the results of the work carried out.

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Esteban, Miguel, Hiroshi Takagi, Takahito Mikami, Lama Bahbouh, Austin Becker, Leonard Nurse, Tomoya Shibayama, and Mohammad Nagdee. "How to Carry Out Bathymetric and Elevation Surveys on a Tight Budget: Basic Surveying Techniques for Sustainability Scientists." International Journal of Sustainable Future for Human Security 5, no. 2 (December 7, 2017): 86–91. http://dx.doi.org/10.24910/jsustain/5.2/8691.

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Shi, Jianguang, and Mingxi Zhou. "A Data-Driven Intermittent Online Coverage Path Planning Method for AUV-Based Bathymetric Mapping." Applied Sciences 10, no. 19 (September 24, 2020): 6688. http://dx.doi.org/10.3390/app10196688.

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Bathymetric mapping with Autonomous Underwater Vehicles (AUVs) receives increased attentions in recent years. AUVs offer a lower operational cost and smaller carbon footprint with reduced ship usage, and they can provide higher resolution data when surveying the seabed at a closer distance if compared to ships. However, advancements are still needed to improve the data quality of AUV-based surveys. Unlike mobile robots with deterministic mapping performance, multibeam sonars used in AUV-based bathymetric mapping often yields inconsistent swath width due to the varied seabed elevation and surficial properties. As a result, mapping voids may exist between planned lawnmower transects. Although this could be solved by planning closer lawnmower paths, mission time increases proportionally. Therefore, an onboard path planner is demanded to assure the defined survey objective, i.e., coverage rate. Here in this paper, we present a new data-driven coverage path planning (CPP) method, in which the vehicle automatically updates the waypoints intermittently based on an objective function constructed using the information about the exploration preference, sonar performance, and coverage efficiency. The goal of the proposed method is to plan a cost-effective path on-the-fly to obtain high quality mapping result meeting the requirements in coverage rate and uncertainty. The proposed CPP method has been evaluated in a simulated environment with a 6DOF REMUS AUV model and a realistic seafloor topography. A series of trials has been conducted to investigate the performance affected by the parameters in the objective function. We also compared the proposed method with traditional lawnmower and spiral paths. The results show that the weight assignment in the objective function is critical as they affect the overall survey performance. With proper weight settings, the AUV yields better survey performance, coverage rate and coverage efficiency, compared to traditional approaches. Moreover, the proposed method can be easily adjusted or modified to achieve different coverage goals, such as rapid data gathering of the entire region, survey of irregular workspace, or maintaining real time path planning.

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Wang, Y., T. Kato, R. Abe, N. Maebashi, T. Tachi, and N. Kishimoto. "ACCURACY OF MEASURING THE BOTTOM OF A POND BY AIRBORNE LIDAR BATHYMETRY (ALB)." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLIII-B1-2020 (August 6, 2020): 73–78. http://dx.doi.org/10.5194/isprs-archives-xliii-b1-2020-73-2020.

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Abstract. Airborne Lidar Bathymetry (ALB) is a technology for characterizing the depths of shallow-water bodies in relatively transparent waters from an airborne platform using a scanning and pulsed light beam. A bathymetric LiDAR usually uses wo laser pulses: one is a near-infrared (NIR) laser pulse for land topography and the other is a green laser pulse for submarine topography. In recent years, ALB has become more popular in river and coastal surveying in Japan. The accuracy of ALB has been verified by comparison with the results of acoustic sounding or levelling. However, since the comparison with either acoustic sounding or levelling is limited to a partial comparison at a point or on a line such as a cross section, it is not suitable for overall verification for detailed terrain features. In addition, accuracy verification by comparison between the results of ALB's green laser scanning and those of NIR laser scanning has been performed in the past only on land, but not in water. As scattering of the green laser occurs when measuring in water, it is possible to affirm that the verification under actual operating conditions has not been sufficiently investigated. In this study, we conducted NIR laser scanning in a natural pond and an artificial pool when they had no water, and conducted green laser scanning when they were filled with water. Thus, the NIR laser scanning and the green laser scanning could be compared in terms of surface measurement for the same bottom of the water body. It was confirmed that the green laser in water has sufficient accuracy compared to the NIR laser in actual operation conditions.

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Kordella, Stavroula, Dimitris Christodoulou, Elias Fakiris, Maria Geraga, Sotiris Kokkalas, Giuditta Marinaro, Margarita Iatrou, George Ferentinos, and George Papatheodorou. "Gas Seepage-Induced Features in the Hypoxic/Anoxic, Shallow, Marine Environment of Amfilochia Bay, Amvrakikos Gulf (Western Greece)." Geosciences 11, no. 1 (January 5, 2021): 27. http://dx.doi.org/10.3390/geosciences11010027.

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Amfilochia Bay (Eastern Amvrakikos Gulf, Western Greece), a complex marine area affected by tectonism, was investigated for seabed seepage manifestations and for possible inter-relationships between shallow gas accumulations and hypoxia. For this purpose, an integrated research methodology that combined geophysical, geochemical, and hydrographic surveys was applied. Marine geophysical and bathymetric surveys led to the discovery of a gas-induced pockmark group in the study area. Oceanographic surveying confirmed that the bay is hypoxic/anoxic below a depth of 15 m (dissolved oxygen from ~4 to 60 μM). Very weak CH4 seepage was detected in correspondence to the pockmark group that seemed to slightly enhance the hypoxic environment locally and close to the seabed, with no effect in shallower waters and the oxycline. Methane isotopic analysis showed variable carbon isotopic composition (from −41‰ to −86‰) which could be either related to differential CH4 oxidation or mixing between microbial and thermogenic gas. However, the pathway of degassing is clearly related to the fault-controlled pockmark group. A protrusion mound, which has erroneously been reported as a submarine “volcano” since 1876, could be the result of mud volcanism based on the geophysical data of this study.

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Karetnikov, Vladimir, Sergey Rudykh, and Aleksandra Ivanova. "Efficiency of modern geoinformation technologies application at survey works designing on inland waterways of Russia." MATEC Web of Conferences 265 (2019): 02016. http://dx.doi.org/10.1051/matecconf/201926502016.

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Survey works on inland waterways can be contingently divided into two directions. The first ones are directed at maintaining the given dimensions of the waterway and are carried out with the use of technical fleet vessels, which includes the dredging fleet. At the same time the basis creation, the results verification and the control of the survey works implementation are carried out by the survey party. The main types of work here are surveying and trawling works, the implementation of which is carried out at the present time on the inland waterways of Russia using geo information technologies, which makes it possible to improve the quality and efficiency of their realization. Such an approach, firstly, has a positive effect on the implementation of the navigational hydrographic support system of navigators, including in the part of electronic cartography, and secondly, it allows to provide the survey works realization at the modern level. The most effective approaches and methods of modern geo information technologies application, implemented for the collection and processing of high-precision bathymetric information and positioning data to ensure the navigation safety on the inland waterways of the Russian Federation, are considered in the paper.

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El-Rabbany, Ahmed. "Assessment of Hydrographic Data Uncertainty for Seamless Reference Surface." Journal of Navigation 59, no. 2 (April 6, 2006): 213–20. http://dx.doi.org/10.1017/s0373463306003729.

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The development of a seamless vertical reference surface is accompanied by a number of challenges pertinent to the availability, volume and uncertainty of bathymetric and topographic data. Data uncertainty, which is by far the most difficult to deal with, is attributed to various sources of errors including those of geodetic and hydrographic origin. The uncertainties in the geodetic measurements originate mainly from the limitations in the geodetic technique employed, i.e. terrestrial or space. Old nautical charts and topographic maps were based on terrestrial techniques, which are far less accurate than modern space techniques. In addition, the distribution of the positioning uncertainty is not expected to follow a consistent pattern across the chart (map). This is mainly due to the inconsistent datum distortion as well as the discrepancies in the measuring techniques in the subsequent chart (map) versions. The existing paper (and digitized) charts in many areas of the world were also based on old hydrographic surveying methods, for example the lead-line, which are far less accurate than modern techniques such as multibeam echo-sounding surveys. This creates inconsistent depth uncertainty across the chart. As uncertainties are propagated into the estimated transformation parameters, estimated positions and their covariance matrix, it is of utmost importance that they are properly modelled. This paper addresses the issue of uncertainty in hydrographic data and suggests ways to account for it.

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Matheen, Nashwan, Mitchell D. Harley, Ian L.Turner, Joshua A. Simmons, and Mandi Thran. "DO WE NEED PRE-STORM SURVEYED BATHYMETRY FOR OPERATIONAL EROSION FORECASTING? EVALUATION OF REPRESENTATIVE AND SYNTHETIC BATHYMETRY ALTERNATIVES." Coastal Engineering Proceedings, no. 36v (December 28, 2020): 13. http://dx.doi.org/10.9753/icce.v36v.sediment.13.

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Immediate pre-storm bathymetry is a key input required for numerical models used in coastal hazard Early Warning Systems. However, the expense and challenging nature of hydrographic surveying means that the availability of high-quality data is extremely rare. This study evaluates the extent to which synthetic and representative bathymetry alternatives can be used to obtain reliable predictions of storm induced sub-aerial erosion using the XBeach coastal erosion numerical model. Multiple storm events at 2 contrasting sites are modelled using 6 bathymetry scenarios including pre-storm surveyed bathymetries, an average bathymetry, and Dean profiles. The output is analysed to evaluate the skill of XBeach erosion predictions as a function of the bathymetry used.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/bE3aXVXxZqQ

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Suhari, K. T., H. Karim, P. H. Gunawan, and H. Purwanto. "SMALL ROV MARINE BOAT FOR BATHYMETRY SURVEYS OF SHALLOW WATERS – POTENTIAL IMPLEMENTATION IN MALAYSIA." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-4/W5 (October 10, 2017): 201–8. http://dx.doi.org/10.5194/isprs-archives-xlii-4-w5-201-2017.

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Current practices in bathymetry survey (available method) are indeed having some limitations. New technologies for bathymetry survey such as using unmanned boat has becoming popular in developed countries - filled in and served those limitations of existing survey methods. Malaysia as one of tropical country has it own river/water body characteristics and suitable approaches in conducting bathymetry survey. Thus, a study on this emerging technology should be conducted using enhanced version of small ROV boat with Malaysian rivers and best approaches so that the surveyors get benefits from the innovative surveying product. Among the available ROV boat for bathymetry surveying in the market, an Indonesian product called SHUMOO is among the promising products – economically and practically proven using a few sample areas in Indonesia. The boat was equipped and integrated with systems of remote sensing technology, GNSS, echo sounder and navigational engine. It was designed for riverbed surveys on shallow area such as small /medium river, lakes, reservoirs, oxidation/detention pond and other water bodies. This paper tries to highlight the needs and enhancement offered to Malaysian’ bathymetry surveyors/practitioners on the new ROV boat which make their task easier, faster, safer, economically effective and better riverbed modelling results. The discussion continues with a sample of Indonesia river (data collection and modelling) since it is mostly similar to Malaysia’s river characteristics and suggests some improvement for Malaysia best practice.

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Pastol, Yves. "Use of Airborne LIDAR Bathymetry for Coastal Hydrographic Surveying: The French Experience." Journal of Coastal Research 62 (March 2011): 6–18. http://dx.doi.org/10.2112/si_62_2.

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Kim, Gyeongyeop, Gunhwan Choi, and Kyungmo Ahn. "Correction Algorithm of Errors by Seagrasses in Coastal Bathymetry Surveying Using Drone and HD Camera." Journal of Korean Society of Coastal and Ocean Engineers 32, no. 6 (December 31, 2020): 553–60. http://dx.doi.org/10.9765/kscoe.2020.32.6.553.

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Choi, Hyun. "Design and Running of a Surveying Ship for Bathymetry of The Manned and Unmanned Control System." Journal of the Korean Institute of Information and Communication Engineering 15, no. 1 (January 31, 2011): 16–21. http://dx.doi.org/10.6109/jkiice.2011.15.1.016.

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Howe, Marian, Marc O. Lammars, and Robin W. Bair. "Participatory science and directed survey methods: A case study with odontocetes in the Maui Nui region of the Hawaiian Islands." IWC Journal of Cetacean Research and Management 20, no. 1 (January 1, 2019): 101–9. http://dx.doi.org/10.47536/jcrm.v20i1.235.

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Given the difficulties and costs often associated with surveying cetaceans, enlisting members of the public to collect data offers a promisingalternative approach. Comparison of cetacean ‘participatory science’ (also known as ‘citizen science’) data with data collected during traditionalscientific studies helps reveal the strengths and weaknesses of a participatory science approach. With a large number of vessel operators on thewater throughout the year, including dolphin-oriented tour boats, the Hawaiian Islands offer an ideal study site to employ such a dual-methodcomparison. The study aimed to enhance understanding of nearshore dolphin distributions relative to bathymetry. Operators of tour and fishingvessels within the shallow Maui Nui basin of the Hawaiian Islands were recruited to report delphinid sightings. Researchers conducted standarddolphin surveys within the same region. The participatory science approach was successful in generating a large sample size of sightings from fivedifferent species. Findings here demonstrate the potential value of participatory science and of using a multimethod approach to infer odontocetedistribution trends relative to bathymetry in areas where both methods are feasible. Important refinements for future projects are highlighted.

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PAVANATO, H. J., C. Gomez Salazar, D. Lima, M. Paschoalini, N. Ristau, and M. Marmontel. "Density, abundance and group size of river dolphins (Inia geoffrensis and Sotalia fluviatilis) in Central Amazonia, Brazil." IWC Journal of Cetacean Research and Management 20, no. 1 (January 1, 2019): 93–100. http://dx.doi.org/10.47536/jcrm.v20i1.238.

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Given the difficulties and costs often associated with surveying cetaceans, enlisting members of the public to collect data offers a promisingalternative approach. Comparison of cetacean ‘participatory science’ (also known as ‘citizen science’) data with data collected during traditionalscientific studies helps reveal the strengths and weaknesses of a participatory science approach. With a large number of vessel operators on thewater throughout the year, including dolphin-oriented tour boats, the Hawaiian Islands offer an ideal study site to employ such a dual-methodcomparison. The study aimed to enhance understanding of nearshore dolphin distributions relative to bathymetry. Operators of tour and fishingvessels within the shallow Maui Nui basin of the Hawaiian Islands were recruited to report delphinid sightings. Researchers conducted standarddolphin surveys within the same region. The participatory science approach was successful in generating a large sample size of sightings from fivedifferent species. Findings here demonstrate the potential value of participatory science and of using a multimethod approach to infer odontocetedistribution trends relative to bathymetry in areas where both methods are feasible. Important refinements for future projects are highlighted.

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Richter, K., D. Mader, P. Westfeld, and H. G. Maas. "WATER TURBIDITY ESTIMATION FROM LIDAR BATHYMETRY DATA BY FULL-WAVEFORM ANALYSIS – COMPARISON OF TWO APPROACHES." International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLIII-B2-2021 (June 28, 2021): 681–88. http://dx.doi.org/10.5194/isprs-archives-xliii-b2-2021-681-2021.

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Abstract. Airborne LiDAR bathymetry is an efficient technique for surveying the bottom of shallow waters. In addition, the measurement data contain valuable information about the local turbidity conditions in the water body. The extraction of this information requires appropriate evaluation methods examining the decay of the recorded waveform signal. Existing approaches are based on several assumptions concerning the influence of the ALB system on the waveform signal, the extraction of the volume backscatter, and the directional independence of turbidity. The paper presents a novel approach that overcomes the existing limitations using two alternative turbidity estimation methods as well as different variants of further processed full-waveform data. For validation purposes, the approach was applied to a data set of a shallow inland water. The results of the quantitative evaluation show, which method and which data basis is best suited for the derivation of area wide water turbidity information.

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Kogut, Tomasz, Joachim Niemeyer, and Aleksandra Bujakiewicz. "Neural networks for the generation of sea bed models using airborne lidar bathymetry data." Geodesy and Cartography 65, no. 1 (June 1, 2016): 41–54. http://dx.doi.org/10.1515/geocart-2016-0007.

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Abstract Various sectors of the economy such as transport and renewable energy have shown great interest in sea bed models. The required measurements are usually carried out by ship-based echo sounding, but this method is quite expensive. A relatively new alternative is data obtained by airborne lidar bathymetry. This study investigates the accuracy of these data, which was obtained in the context of the project ‘Investigation on the use of airborne laser bathymetry in hydrographic surveying’. A comparison to multi-beam echo sounding data shows only small differences in the depths values of the data sets. The IHO requirements of the total horizontal and vertical uncertainty for laser data are met. The second goal of this paper is to compare three spatial interpolation methods, namely Inverse Distance Weighting (IDW), Delaunay Triangulation (TIN), and supervised Artificial Neural Networks (ANN), for the generation of sea bed models. The focus of our investigation is on the amount of required sampling points. This is analyzed by manually reducing the data sets. We found that the three techniques have a similar performance almost independently of the amount of sampling data in our test area. However, ANN are more stable when using a very small subset of points.

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Elsobeiey, Mohamed Elsayed. "Accuracy Assessment of Satellite-Based Correction Service and Virtual GNSS Reference Station for Hydrographic Surveying." Journal of Marine Science and Engineering 8, no. 7 (July 20, 2020): 542. http://dx.doi.org/10.3390/jmse8070542.

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The aim of this paper is to assess the performance of satellite-based correction service, Trimble PP-RTX, and Virtual Reference Stations (VRS) for bathymetry determination, and check how far these techniques meet the minimum standards of the International Hydrography Organization (IHO) for hydrographic surveys. To this end, a three-hour duration session was conducted at Sharm Obhur using KAU-Hydrography 1 vessel. This session includes Global Navigation Satellite System (GNSS) data at the base station using Trimble SPS855 GNSS receiver, multibeam records using Kongsberg EM 712 multibeam echo sounder, sound velocity profile using Valeport’s sound velocity profiler, Applanix POS MV measurements, and real-time PP-RTX corrections. Moreover, the VRS GNSS data was generated using Kingdom of Saudi Arabia Continuous Operation Reference Station network (KSA-CORS). It is shown that the Total Horizontal Uncertainty (THU) and Total Vertical Uncertainty (TVU) of the PP-RTX technique are 5.50 cm and 5.90 cm, respectively, which meets the IHO minimum standards for all survey orders at 95% confidence level. The THU and TVU of the VRS technique, on the other hand, are 5.75 cm and 7.05 cm at 95% confidence level, respectively. These values meet the IHO standards for all survey orders as well. Statistical analysis of the seabed surface differences showed a −0.07 cm average difference between the PP-RTX seabed surface and the reference seabed surface with a standard deviation of 3.60 cm. However, the average difference between the VRS-based seabed surface and the reference seabed surface is −0.03 cm and a standard deviation of 3.61 cm.

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Ahola, Ryan, René Chénier, Mesha Sagram, and Bradley Horner. "The impact of sensors for satellite derived bathymetry within the Canadian Arctic." Geomatica 74, no. 2 (June 1, 2020): 46–64. http://dx.doi.org/10.1139/geomat-2019-0022.

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Canada’s coastline presents challenges for charting. Within Arctic regions, in situ surveying presents risks to surveyors, is time consuming and costly. To better meet its mandate, the Canadian Hydrographic Service (CHS) has been investigating the potential of remote sensing to complement traditional charting techniques. Much of this work has focused on evaluating the effectiveness of empirical satellite derived bathymetry (SDB) techniques within the Canadian context. With greater knowledge of applying SDB techniques within Canadian waters, CHS is now interested in understanding how characteristics of optical sensors can impact SDB results. For example, how does the availability of different optical bands improve or hinder SDB estimates? What is the impact of spatial resolution on SDB accuracy? Do commercial satellites offer advantages over freely available data? Through application of a multiple band modelling technique to WorldView-2, Pléiades, PlanetScope, SPOT, Sentinel-2, and Landsat-8 imagery obtained over Cambridge Bay, Nunavut, this paper provides insight into these questions via comparisons with in situ survey data. Result highlights in the context of these questions include the following: Similarities between sensors: Overall linear error at 90% (LE90) results for each sensor ranged from 0.88 to 1.91 m relative to in situ depths, indicating consistency in the accuracy of SDB estimates from the examined satellites. Most estimates achieved Category of Zone of Confidence level C accuracy, the suggested minimum survey accuracy level for incorporating SDB information into navigational charts. SDB coverage: Between sensors, differences in the area of the sea floor that could be measured by SDB were apparent, as were differences in the ability of each sensor to properly represent spatial bathymetry characteristics. Sensor importance: Though relationships between SDB accuracy and sensor resolution were found, significant advantages or disadvantages for particular sensors were not identified, suggesting that other factors may play a more important role for SDB image selection (e.g., sea floor visibility, sediments, waves). Findings from this work will help inform SBD planning activities for hydrographic offices and SDB researchers alike.

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Westhead, Keith, Kay Smith, Evelyn Campbell, Andrew Colenutt, and Stuart McVey. "Pushing the boundaries: Integration of multi-source digital elevation model data for seamless geological mapping of the UK's coastal zone." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 105, no. 4 (December 2014): 263–71. http://dx.doi.org/10.1017/s1755691015000134.

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ABSTRACTRecent advances in marine acoustic survey and land-based topographic monitoring technologies have resulted in increasingly cost-effective data acquisition in coastal areas. The DEFRA-funded National Network of Regional Coastal Monitoring Programmes of England are, for example, utilising swath bathymetry and airborne light detection and ranging (LiDAR) technology more routinely to survey the coastal zone around the coastline of England. The demand for data processing, visualisation and interpretation techniques to keep pace with such advances in data acquisition is clear. This study discusses collection and processing techniques for such data on the south coast of Dorset, England, which have enabled the production of a seamless, high spatial resolution digital elevation model across the coastal zone. Case studies demonstrate how this elevation model can be viewed and analysed using state-of-the-art digital techniques to allow geological mapping to be extended from onshore to offshore in unprecedented detail, effectively eliminating what is known as the ‘White Ribbon’ for coastal geological mapping. The potential for rolling out such techniques for wider surveying programmes across many environmental disciplines is significant, which could contribute towards improving the multi-disciplinary scientific evidence base in the complex coastal zone.

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Barrile, V., A. Fotia, R. Ponterio, and F. Aliotta. "PHOTOGRAMMETRIC TECHNIQUES FOR THE RECONSTRUCTION OF UNDERWATER 3D MODELS OF SEABED AND ARTIFACTS." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W10 (April 17, 2019): 25–30. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w10-25-2019.

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Abstract. The digital representation of hydraulic engineering works such as dykes or barriers is a sector that is becoming increasingly important. In general, however, the 3D relief of semi-submerged structures is still a problem. The Geomatics Laboratory in collaboration with CNR-IPCF of Messina as part of a broader project to analyze the variations of the coast lines and the seabed of the province of Reggio Calabria (southern Italy), has developed an experimental system of acquisition and processing of digital images acquired via UAV and (Remotely operated vehicle) ROV. The present note describes the design and construction characteristics of the ROV realized and used, the advantages and limitations of the use of a small and low-cost ROV, as well as the results obtained during the experimentation phase. The process of surveying of the sub-emerged structure inquired and the relative construction of a unique 3D model are also described. The two surveys were first elaborated separately and then united in a single reference system by means of the visible markers in the area straddling the sea surface. Finally, the bathymetry values obtained from the classic echo sounder system and those obtained from the model obtained were compared.

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Journal articles on the topic 'Bathymetric surveying'

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