Journal articles: 'Bathymetric surveys'

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Ochałek, Agnieszka, Tomasz Lipecki, Wojciech Jaśkowski, and Mateusz Jabłoński. "Modeling and Analysis of Integrated Bathymetric and Geodetic Data for Inventory Surveys of Mining Water Reservoirs." E3S Web of Conferences 35 (2018): 04005. http://dx.doi.org/10.1051/e3sconf/20183504005.

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The significant part of the hydrography is bathymetry, which is the empirical part of it. Bathymetry is the study of underwater depth of waterways and reservoirs, and graphic presentation of measured data in form of bathymetric maps, cross-sections and three-dimensional bottom models. The bathymetric measurements are based on using Global Positioning System and devices for hydrographic measurements – an echo sounder and a side sonar scanner. In this research authors focused on introducing the case of obtaining and processing the bathymetrical data, building numerical bottom models of two post-mining reclaimed water reservoirs: Dwudniaki Lake in Wierzchosławice and flooded quarry in Zabierzów. The report includes also analysing data from still operating mining water reservoirs located in Poland to depict how bathymetry can be used in mining industry. The significant issue is an integration of bathymetrical data and geodetic data from tachymetry, terrestrial laser scanning measurements.

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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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Kusuma, Hollanda A., and Nadya Oktaviani. "PENGGUNAAN LIDAR (LIGHT DETECTION AND RANGING) UNTUK MENGUKUR KEDALAMAN PERAIRAN DANGKAL." OSEANA 44, no. 1 (April 30, 2019): 54–69. http://dx.doi.org/10.14203/oseana.2019.vol.44no.1.31.

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UTILIZATION OF LIDAR (LIGHT DETECTION AND RANGING) TO MEASURE SHALLOW WATER DEPTH. Understanding on seabed characteristics such as the topography, composition and habitat conditions was very important to provide information not only for shipping activities, conservation, management and planning activities, but also for research activities with accurate bathymetry data. Accurate bathymetric data can be obtained from hydrographic surveys and remote sensing technology analysis. The hydrographic survey is used to obtain bathymetry data by applying singlebeam echosounder (SBES) and multibeam echosounder (MBES). At a depth of <15m (shallow water) was difficult to carry out an acoustic survey. At present there is one remote sensing technology that can be used to support hydrographic surveys namely Bathymetric LIDAR (Light Detection and Ranging). LIDAR was able to detect objects on land and waters due to being flown by a vehicle. Wide LIDAR sweep makes data acquisition faster and more effective than acoustic noise. Therefore, LIDAR was an alternative to obtain depth data, especially in coastal areas with a depth of less than 50 m.

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Ivanoski, Dragan, Slavisa Trajkovic, and Milan Gocic. "Bathymetric surveys of Shpilje reservoir." Facta universitatis - series: Architecture and Civil Engineering 16, no. 1 (2018): 149–57. http://dx.doi.org/10.2298/fuace170915012i.

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Periodic bathymetric surveys are carried out to define quantity of sedimented material in reservoirs, as well as to determine the areas most endangered by the silting process. Such surveys in the Republic of Macedonia were started as an obligatory and regular practice in the seventies of the last century, immediately after the formation of the larger artificial lakes. These were carried out for almost all reservoirs in the country and it can be said that there is already a sufficient amount of data on some of them that can serve as a basis for high quality analyses of the silting trend of the reservoirs and of the extent to which erosion is affecting the basin area. This paper provides a review of the results from the latest field surveys and analyses of changes in the configuration of the Shpilje reservoir bottom, carried out in the period 2014 to 2016.

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Mateo-Pérez, Vanesa, Marina Corral-Bobadilla, Francisco Ortega-Fernández, and Vicente Rodríguez-Montequín. "Analysis of the Spatio-Temporal Evolution of Dredging from Satellite Images: A Case Study in the Principality of Asturias (Spain)." Journal of Marine Science and Engineering 9, no. 3 (March 2, 2021): 267. http://dx.doi.org/10.3390/jmse9030267.

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One of the fundamental tasks in the maintenance of port operations is periodic dredging. These dredging operations facilitate the elimination of sediments that the coastal dynamics introduce. Dredging operations are increasingly restrictive and costly due to environmental requirements. Understanding the condition of the seabed before and after dredging is essential. In addition, determining how the seabed has behaved in recent years is important to consider when planning future dredging operations. In order to analyze the behavior of sediment transport and the changes to the seabed due to sedimentation, studies of littoral dynamics are conducted to model the deposition of sediments. Another methodology that could be used to analyze the real behavior of sediments would be to study and compare port bathymetries collected periodically. The problem with this methodology is that it requires numerous bathymetric surveys to produce a sufficiently significant analysis. This study provides an effective solution for obtaining a dense time series of bathymetry mapping using satellite data, and enables the past behavior of the seabed to be examined. The methodology proposed in this work uses Sentinel-2A (10 m resolution) satellite images to obtain historical bathymetric series by the development of a random forest algorithm. From these historical bathymetric series, it is possible to determine how the seabed has behaved and how the entry of sediments into the study area occurs. This methodology is applied in the Port of Luarca (Principality of Asturias), obtaining satellite images and extracting successive bathymetry mapping utilizing the random forest algorithm. This work reveals how once the dock was dredged, the sediments were redeposited and the seabed recovered its level prior to dredging in less than 2 months.

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Schifter, Deborah E., Edward R. Franchi, James M. Griffin, and Budd B. Adams. "Reverberation mapping for basin‐wide bathymetric surveys." Marine Geodesy 10, no. 1 (January 1986): 1–33. http://dx.doi.org/10.1080/01490418609388008.

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Bandini, Filippo, Daniel Olesen, Jakob Jakobsen, Cecile Marie Margaretha Kittel, Sheng Wang, Monica Garcia, and Peter Bauer-Gottwein. "Technical note: Bathymetry observations of inland water bodies using a tethered single-beam sonar controlled by an unmanned aerial vehicle." Hydrology and Earth System Sciences 22, no. 8 (August 7, 2018): 4165–81. http://dx.doi.org/10.5194/hess-22-4165-2018.

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Abstract. High-quality bathymetric maps of inland water bodies are a common requirement for hydraulic engineering and hydrological science applications. Remote sensing methods, such as space-borne and airborne multispectral imaging or lidar, have been developed to estimate water depth, but are ineffective for most inland water bodies, because of the attenuation of electromagnetic radiation in water, especially under turbid conditions. Surveys conducted with boats equipped with sonars can retrieve accurate water depths, but are expensive, time-consuming, and unsuitable for unnavigable water bodies. We develop and assess a novel approach to retrieve accurate and high-resolution bathymetry maps. We measured accurate water depths using a tethered floating sonar controlled by an unmanned aerial vehicle (UAV) in a lake and in two different rivers located in Denmark. The developed technique combines the advantages of remote sensing with the potential of bathymetric sonars. UAV surveys can be conducted also in unnavigable, inaccessible, or remote water bodies. The tethered sonar can measure bathymetry with an accuracy of ∼2.1 % of the actual depth for observations up to 35 m, without being significantly affected by water turbidity, bed form, or bed material.

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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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El-Diasty, Mohammed. "Satellite-Based Bathymetric Modeling Using a Wavelet Network Model." ISPRS International Journal of Geo-Information 8, no. 9 (September 12, 2019): 405. http://dx.doi.org/10.3390/ijgi8090405.

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Accurate bathymetric modeling is required for safe maritime navigation in shallow waters as well as for other marine operations. Traditionally, bathymetric modeling is commonly carried out using linear models, such as the Stumpf method. Linear methods are developed to derive bathymetry using the strong linear correlation between the grey values of satellite imagery visible bands and the water depth where the energy of these visible bands, received at the satellite sensor, is inversely proportional to the depth of water. However, without satisfying homogeneity of the seafloor topography, this linear method fails. The current state-of-the-art is represented by artificial neural network (ANN) models, which were developed using a non-linear, static modeling function. However, more accurate modeling can be achieved using a highly non-linear, dynamic modeling function. This paper investigates a highly non-linear wavelet network model for accurate satellite-based bathymetric modeling with dynamic non-linear wavelet activation function that has been proven to be a valuable modeling method for many applications. Freely available Level-1C satellite imagery from the Sentinel-2A satellite was employed to develop and justify the proposed wavelet network model. The top-of-atmosphere spectral reflectance values for the multispectral bands were employed to establish the wavelet network model. It is shown that the root-mean-squared (RMS) error of the developed wavelet network model was about 1.82 m, and the correlation between the wavelet network model depth estimate and “truth” nautical chart depths was about 95%, on average. To further justify the proposed model, a comparison was made among the developed, highly non-linear wavelet network method, the Stumpf log-ratio method, and the ANN method. It is concluded that the developed, highly non-linear wavelet network model is superior to the Stumpf log-ratio method by about 37% and outperforms the ANN model by about 21%, on average, on the basis of the RMS errors. Also, the accuracy of the bathymetry-derived wavelet network model was evaluated on the basis of the International Hydrographic Organization (IHO)’s standards for all survey orders. It is shown that the accuracy of the bathymetry derived from the wavelet network model does not meet the IHO’s standards for all survey orders; however, the wavelet network model can still be employed as an accurate and powerful tool for survey planning when conducting hydrographic surveys for new, shallow water areas.

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Chénier, René, Marc-André Faucher, Ryan Ahola, Yask Shelat, and Mesha Sagram. "Bathymetric Photogrammetry to Update CHS Charts: Comparing Conventional 3D Manual and Automatic Approaches." ISPRS International Journal of Geo-Information 7, no. 10 (October 2, 2018): 395. http://dx.doi.org/10.3390/ijgi7100395.

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The Canadian Hydrographic Service (CHS) supports safe navigation within Canadian waters through approximately 1000 navigational charts as well as hundreds of publications. One of the greatest challenges faced by the CHS is removing gaps in bathymetric survey data, particularly in the Canadian Arctic where only 6% of navigational water is surveyed to modern standards. Therefore, the CHS has initiated a research project to explore remote sensing methods to improve Canadian navigational charts. The major components of this project explore satellite derived bathymetry (SDB), coastline change detection and coastline extraction. This paper focuses on the potential of two stereo satellite techniques for deriving SDB: (i) automatic digital elevation model (DEM) extraction using a semi-global matching method, and (ii) 3D manual delineation of depth contours using visual stereoscopic interpretation. Analysis focused on quantitative assessment which compared estimated depths from both automatic and 3D manual photogrammetric approaches against available in situ survey depths. The results indicate that the 3D manual approach provides an accuracy of < 2 m up to a depth of 15 m. Comparable results were obtained from the automatic approach to a depth of 12 m. For almost all investigated depth ranges for both techniques, uncertainties were found to be within the required vertical accuracies for the International Hydrographic Organization category zone of confidence (CATZOC) level C classification for hydrographic surveys. This indicates that both techniques can be used to derive navigational quality bathymetric information within the investigated study site. While encouraging, neither technique was found to offer a single solution for the complete estimation of depth within the study area. As a result of these findings, the CHS envisions a hybrid approach where stereo- and reflectance-based bathymetry estimation techniques are implemented to provide the greatest understanding of depth possible from satellite imagery. Overall, stereo photogrammetry techniques will likely allow for new potential for supporting the improvement of CHS charts in areas where modern surveys have not yet been obtained.

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Ferreira, Italo Oliveira, Dalto Domingos Rodrigues, Gérson Rodrigues dos Santos, and Lidiane Maria Ferraz Rosa. "IN BATHYMETRIC SURFACES: IDW OR KRIGING?" Boletim de Ciências Geodésicas 23, no. 3 (September 2017): 493–508. http://dx.doi.org/10.1590/s1982-21702017000300033.

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Abstract: The representation of the submerged relief is very importance in diverse areas of knowledge such as Projects to build or reassess port dimensions, installation of moles, ducts, marinas, bridges, tunnels, mineral prospecting, waterways, dredging, silting control of river and lakes, and others. The depths of the aquatic bodies, indispensable for the representation of those, are obtained through the bathymetric surveys. However, the result of a bathymetric sampling is a grid of points that, for itself, it is not capable of generating directly the Digital Model of Depth (DMD), being necessary the use of interpolators. Currently, there are more than 40 available scientific methods of interpolation, each one with its particularities and characteristics. This study has the objective to analise, comparing, the efficiency of Universal Kriging (UK) and of the Inverse Distance Weighted (IDW) in the computational representation of bathymetric surfaces, varying in a decreasing way the quantity of sample points. Through the results, we can be stated the superiority of the interpolator Universal Kriging in efficiency in creating DMD with basis in the bathymetric surveys data.

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Iwen, Dominik, and Mariusz Wąż. "Detection of Small Bottom Objects From Multibeam Echosounder Data." Annual of Navigation 25, no. 1 (December 1, 2018): 219–32. http://dx.doi.org/10.1515/aon-2018-0015.

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AbstractMultibeam Echo Sounder Systems (MBES) shallow water surveys provide capability not only acquiring bathymetric data useful for determining isobaths and mapping features on the seafloor which may be a hazard to navigation. They also allow detection of objects smaller or deeper than those required for the safety of seafaring and International Hydrography Organization (IHO) standards. In this article some of issues related to of efficient MBES shallow water surveys are stressed. Additionally a draft of post-processing techniques and result data format together with tools allowing extraction of bottom object from bathymetric data are presented.

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Hashimoto, Kana, Takenori Shimozono, Yoshinao Matsuba, and Takumi Okabe. "Unmanned Aerial Vehicle Depth Inversion to Monitor River-Mouth Bar Dynamics." Remote Sensing 13, no. 3 (January 25, 2021): 412. http://dx.doi.org/10.3390/rs13030412.

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Monitoring the morphological evolution of a river-mouth bar is of both practical and scientific importance. A large amount of sediment is transported from a river to surrounding littoral cells via a deltaic bar after an extreme weather event. However, it is often not feasible to capture drastic morphological changes in the short term with conventional bathymetric surveys. This paper presents a depth-inversion method based on unmanned aerial vehicle technology to estimate two-dimensional bathymetry from video-sensed swell propagation. The estimation algorithm is tested over four cases with varying wave and bathymetric conditions and is validated with transect survey data. The test results suggest that the method can estimate deltaic-bar topography in front of a river mouth with a root-mean-square error of <0.5 m. The applicable range is limited by wave breaking in the inner bar and up to a depth of ~8 m, where swell intensity signals become ambiguous. A comparison of the different cases shows that the method works better under calm weather conditions with dominant swells propagating from non-local sources. Significant morphological changes of a river-mouth bar due to a powerful typhoon are successfully detected by observations right before and after the event.

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Remini, Boualem, Djllali Bensafia, and Tahar Nasroun. "Impact of sediment transport of the Chellif River on silting of the Boughezoul reservoir (Algeria)." Journal of Water and Land Development 24, no. 1 (March 1, 2015): 35–40. http://dx.doi.org/10.1515/jwld-2015-0005.

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Abstract In this article, we discussed the effect of sediment transport in the Chellif catchment on the silting of Boughezoul reservoir. Since 1934, when the impoundment of the dam, nine bathymetric surveys were carried out by hydraulic services. Based on the last two bathymetric surveys (1986 and 2005), we assessed the average annual rate of silting 0.67 million m3·year−1. Is a filling rate of 70% of the total capacity of the reservoir in 2011. Storage capacity has decreased from 55 million m3 in 1934 to 15 million m3 in 2011. Concentrations exceeding 300 g·l−1, recorded in the river upstream of Boughezoul reservoir, caused formation of density currents.

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ROMEO, T., L. CASTRIOTA, P. CONSOLI, M. FALAUTANO, G. FLORIO, F. PERDICHIZZI, M. G. FINOIA, F. ANDALORO, and P. RINELLI. "Bathymetric and longitudinal distribution analyysis of the rockfish Helicolenus Dactylopterus (Delaroche, 1809) in the southern Tyrrhenian Sea (central Mediterranean)." Mediterranean Marine Science 10, no. 1 (June 1, 2009): 73. http://dx.doi.org/10.12681/mms.123.

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This study provides information on bathymetric and longitudinal distribution heterogeneity of the rockfish Helicolenus dactylopterus in the southern Tyrrhenian Sea. Data were drawn from experimental bottom trawl (1996-2002) plus bottom trap (2001-02) surveys. The frequency of occurrence and mean relative density (N/km2) and biomass (kg/km2) indexes were calculated for two survey seasons (spring and autumn), four geographic sectors and three depth strata. MANOVA was used to test fish abundance among years, sectors and strata. Analysis of the length-frequency distributions was carried out by two-way (gears and depths) ANOVA, post hoc multiple comparisons for testing differences among depths and Student’s t test for testing differences between gears. Length-weight relationship was also estimated and the allometric coefficient was tested with the Student’s t test. The results showed a significant positive bathymetric gradient of sizes both for trawl and trap surveys; at same depths, fish caught by traps were significantly longer than those caught by trawl. In spring surveys, significant differences were found among strata for both abundance indexes; in autumn surveys, significant differences between depth strata were found only for density indices. The distribution and abundance patterns of H. dactylopterus along the southern Tyrrhenian Sea was homogeneous among sectors. Length-weight relationship showed a significant positive allometric growth.

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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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Muhari, Abdul, Mohammad Heidarzadeh, Harjo Susmoro, Haris D. Nugroho, Estu Kriswati, Supartoyo, Antonius B. Wijanarto, Fumihiko Imamura, and Taro Arikawa. "The December 2018 Anak Krakatau Volcano Tsunami as Inferred from Post-Tsunami Field Surveys and Spectral Analysis." Pure and Applied Geophysics 176, no. 12 (November 21, 2019): 5219–33. http://dx.doi.org/10.1007/s00024-019-02358-2.

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AbstractWe present analysis of the December 2018 Anak Krakatau tsunami in Sunda Strait, Indonesia, from a combination of post-tsunami field surveys, bathymetric changes and spectral analysis of the tsunami tide gauge records. Post-tsunami surveys revealed moderate tsunami height along the coast of Sumatra and Java with maximum surveyed runup of 13.5 m and maximum inundation distance of 330 m. At small islands located close to the volcano, extreme tsunami impacts were observed indicating not only a huge tsunami was generated by large amounts of collapse material which caused notable changes of seafloor bathymetry, but also indicates the role of those small islands in reducing tsunami height that propagated to the mainland of Indonesia. Our spectral analysis of tide gauge records showed that the tsunami’s dominant period was 6.6–7.4 min, indicating the short-period nature of the 2018 Sunda Strait tsunami.

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Benassai, Guido, Pietro Aucelli, Giorgio Budillon, Massimo De Stefano, Diana Di Luccio, Gianluigi Di Paola, Raffaele Montella, Luigi Mucerino, Mario Sica, and Micla Pennetta. "Rip current evidence by hydrodynamic simulations, bathymetric surveys and UAV observation." Natural Hazards and Earth System Sciences 17, no. 9 (September 12, 2017): 1493–503. http://dx.doi.org/10.5194/nhess-17-1493-2017.

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Abstract. The prediction of the formation, spacing and location of rip currents is a scientific challenge that can be achieved by means of different complementary methods. In this paper the analysis of numerical and experimental data, including RPAS (remotely piloted aircraft systems) observations, allowed us to detect the presence of rip currents and rip channels at the mouth of Sele River, in the Gulf of Salerno, southern Italy. The dataset used to analyze these phenomena consisted of two different bathymetric surveys, a detailed sediment analysis and a set of high-resolution wave numerical simulations, completed with Google EarthTM images and RPAS observations. The grain size trend analysis and the numerical simulations allowed us to identify the rip current occurrence, forced by topographically constrained channels incised on the seabed, which were compared with observations.

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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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Swain, Douglas P. "Age- and Density-Dependent Bathymetric Pattern of Atlantic Cod (Gadus morhua) in the Southern Gulf of St. Lawrence." Canadian Journal of Fisheries and Aquatic Sciences 50, no. 6 (June 1, 1993): 1255–64. http://dx.doi.org/10.1139/f93-142.

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I examined the bathymetric pattern of Alantic cod (Gadus morhua) in September in the southern Gulf of St. Lawrence for age groups 3–8+ over the period 1971–91 using data from annual bottom trawl surveys. Mean age of cod tended to increase with depth in all years. The age-specific bathymetric patterns underlying this relationship differed markedly between periods of low and high abundance. When abundance was high, cod densities tended to be highest at intermediate depths, and the positive correlation between age and depth reflected a tendency for density to be highest in progressively deeper water for older fish. When abundance was low, density was either unrelated to depth or highest in shallow water, and the positive correlation between age and depth reflected a tendency for older cod to be more widely distributed than younger cod (i.e., density decreased less sharply with depth for older cod). I suggest explanations for this density dependence of cod bathymetric pattern and discuss these results in relation to the factors underlying habitat selection and bathymetric segregation by age in this population.

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Di Matteo, A., and M. Milli. "Morphological, bathymetric and sedimentological surveys used to assess the coastline defensive measures." International Journal of Environmental Science & Technology 5, no. 3 (June 2008): 415–24. http://dx.doi.org/10.1007/bf03326037.

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Carrasquilla-Henao, Mauricio, K. Lynne Yamanaka, Dana Haggarty, and Francis Juanes. "Predicting important rockfish (Sebastes spp.) habitat from large-scale longline surveys for southern British Columbia, Canada." Canadian Journal of Fisheries and Aquatic Sciences 76, no. 5 (May 2019): 682–94. http://dx.doi.org/10.1139/cjfas-2017-0458.

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Rockfish, particularly yelloweye (Sebastes ruberrimus) and quillback (Sebastes maliger), are vulnerable to overfishing because they mature late and have affinity for shallow water (50–200 m) habitats. Because studies relating habitat characteristics with the distribution and presence of rockfishes at large scales (100s of kilometres) remain scarce, we sought to investigate the relationships between benthic characteristics with the presence–absence and abundance of rockfishes caught in longline surveys in nearshore waters of southern British Columbia. Habitat parameters were calculated from a 20 m resolution bathymetry layer. Yelloweye and quillback were examined separately and combined with 19 other rockfish species in a species aggregate (total rockfish); occurrence data were fitted with generalized linear mixed effects models, and abundance data were fitted with zero-inflated mixed effects models. The relationship between rockfish abundance with presence–absence and slope, distance to rocky habitat, and fine bathymetric position index suggests that these species prefer rocky, steep habitat. While underwater visual observation data offer measures of visual fish habitat and abundance, longline surveys may be a more cost-effective method for large-scale studies.

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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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Fassoni-Andrade, Alice César, Fabien Durand, Daniel Moreira, Alberto Azevedo, Valdenira Ferreira dos Santos, Claudia Funi, and Alain Laraque. "Comprehensive bathymetry and intertidal topography of the Amazon estuary." Earth System Science Data 13, no. 5 (May 26, 2021): 2275–91. http://dx.doi.org/10.5194/essd-13-2275-2021.

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Abstract. The characterization of estuarine hydrodynamics primarily depends on knowledge of the bathymetry and topography. Here, we present the first comprehensive, high-resolution dataset of the topography and bathymetry of the Amazon River estuary, the world's largest estuary. Our product is based on an innovative approach combining spaceborne remote sensing data, an extensive and processed river depth dataset, and auxiliary data. Our goal with this mapping is to promote the database usage in studies that require this information, such as hydrodynamic modeling or geomorphological assessments. Our twofold approach considered 500 000 sounding points digitized from 19 nautical charts for bathymetry estimation, in conjunction with a state-of-the-art topographic dataset based on remote sensing, encompassing intertidal flats, riverbanks, and adjacent floodplains. Finally, our estimate can be accessed in a unified 30 m resolution regular grid referenced to the Earth Gravitational Model 2008 (EGM08), complemented both landward and seaward by land (Multi-Error-Removed Improved-Terrain digital elevation model, MERIT DEM) and ocean (General Bathymetric Chart of the Oceans version 2020, GEBCO_2020) topographic data. Extensive validation against independent and spatially distributed data, from an airborne lidar survey, from ICESat-2 altimetric satellite data, and from various in situ surveys, shows a typical vertical accuracy of 7.2 m (riverbed) and 1.2 m (non-vegetated intertidal floodplains). The dataset is available at https://doi.org/10.17632/3g6b5ynrdb.2 (Fassoni-Andrade et al., 2021).

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Ghorbanidehno, Hojat, Jonghyun Lee, Matthew Farthing, Tyler Hesser, Peter K. Kitanidis, and Eric F. Darve. "Novel Data Assimilation Algorithm for Nearshore Bathymetry." Journal of Atmospheric and Oceanic Technology 36, no. 4 (April 2019): 699–715. http://dx.doi.org/10.1175/jtech-d-18-0067.1.

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AbstractIt can be expensive and difficult to collect direct bathymetry data for nearshore regions, especially in high-energy locations where there are temporally and spatially varying bathymetric features like sandbars. As a result, there has been increasing interest in remote assessment techniques for estimating bathymetry. Recent efforts have combined Kalman filter–based techniques with indirect video-based observations for bathymetry inversion. Here, we estimate nearshore bathymetry by utilizing observed wave celerity and wave height, which are related to bathymetry through phase-averaged wave dynamics. We present a modified compressed-state Kalman filter (CSKF) method, a fast and scalable Kalman filter method for linear and nonlinear problems with large numbers of unknowns and measurements, and apply it to two nearshore bathymetry estimation problems. To illustrate the robustness and accuracy of our method, we compare its performance with that of two ensemble-based approaches on twin bathymetry estimation problems with profiles based on surveys taken by the U.S. Army Corps of Engineer Field Research Facility (FRF) in Duck, North Carolina. We first consider an estimation problem for a temporally constant bathymetry profile. Then we estimate bathymetry as it evolves in time. Our results indicate that the CSKF method is more accurate and robust than the ensemble-based methods with the same computational cost. The superior performance is due to the optimal low-rank representation of the covariance matrices.

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Weinberg, James R. "Bathymetric shift in the distribution of Atlantic surfclams: response to warmer ocean temperature." ICES Journal of Marine Science 62, no. 7 (January 1, 2005): 1444–53. http://dx.doi.org/10.1016/j.icesjms.2005.04.020.

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Abstract Standard research vessel surveys during the 1980s and early 1990s demonstrated that Atlantic surfclams (Spisula solidissima solidissima) were common in the southern portion of their range (37–38°N) along the east coast of North America in the Delmarva region. Based on data from these surveys, the probability of capturing surfclams in shallow water (i.e. 20 m) tows of the Delmarva region was 75–85% in 1994 and 1997. In 1999 and 2002, this probability declined to 40–55%. The probability of capturing surfclams in survey tows from deeper waters (40–50 m) also declined, but this change was relatively small compared with that in shallower water. These changes were not the result of commercial clam fishing. Unusually warm water, which induces thermal stress in S. s. solidissima, was prevalent within the period from 1999 to 2002 over the Delmarva continental shelf during fall when annual bottom temperature was peaking. The combined effects of poor physiological condition and thermal stress likely resulted in mortality of Atlantic surfclams in shallow water habitats in the Delmarva region. This resulted in a shift in the bathymetric distribution of the population to deeper water. Between 1982 and 1997, most of the surfclams in the Delmarva region occurred at depths between 25 and 35 m, whereas in 1999 and 2002, most of the Delmarva population occurred at 35–40 m.

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Webster, Tim, Candace MacDonald, Kevin McGuigan, Nathan Crowell, Jean-Sebastien Lauzon-Guay, and Kate Collins. "Calculating macroalgal height and biomass using bathymetric LiDAR and a comparison with surface area derived from satellite data in Nova Scotia, Canada." Botanica Marina 63, no. 1 (February 25, 2020): 43–59. http://dx.doi.org/10.1515/bot-2018-0080.

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AbstractThe ability to map and monitor the macroalgal coastal resource is important to both the industry and the regulator. This study evaluates topo-bathymetric lidar (light detection and ranging) as a tool for estimating the surface area, height and biomass of Ascophyllum nodosum, an anchored and vertically suspended (floating) macroalga, and compares the surface area derived from lidar and WorldView-2 satellite imagery. Pixel-based Maximum Likelihood classification of low tide satellite data produced 2-dimensional maps of intertidal macroalgae with overall accuracy greater than 80%. Low tide and high tide topo-bathymetric lidar surveys were completed in southwestern Nova Scotia, Canada. Comparison of lidar-derived seabed elevations with ground-truth data collected using a survey grade global navigation satellite system (GNSS) indicated the low tide survey data have a positive bias of 15 cm, likely resulting from the seaweed being draped over the surface. The high tide survey data did not exhibit this bias, although the suspended canopy floating on the water surface reduced the seabed lidar point density. Validation of lidar-derived seaweed heights indicated a mean difference of 30 cm with a root mean square error of 62 cm. The modelled surface area of seaweed was 28% greater in the lidar model than the satellite model. The average lidar-derived biomass estimate was within one standard deviation of the mean biomass measured in the field. The lidar method tends to overestimate the biomass compared to field measurements that were spatially biased to the mid-intertidal level. This study demonstrates an innovative and cost-effective approach that uses a single high tide bathymetric lidar survey to map the height and biomass of dense macroalgae.

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Preti, Mentino, and Barbara Zanuttigh. "INTEGRATED BEACH MANAGEMENT AT IGEA MARINA, ITALY: RESULTS OF TEN-YEARS MONITORING." Coastal Engineering Proceedings 1, no. 32 (February 2, 2011): 33. http://dx.doi.org/10.9753/icce.v32.management.33.

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This contribution analyses the hydro-morphological effects induced by low crested structures confined by lateral groynes at Igea Marina beach, Northern Adriatic Sea, Italy. The site has been monitored since the works started for these last ten years. Results from bathymetric surveys, sediment samplings, video monitoring and numerical modelling are presented and discussed.

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Giordano, Francesco, Gaia Mattei, Claudio Parente, Francesco Peluso, and Raffaele Santamaria. "Integrating Sensors into a Marine Drone for Bathymetric 3D Surveys in Shallow Waters." Sensors 16, no. 1 (December 29, 2015): 41. http://dx.doi.org/10.3390/s16010041.

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Laguta, Andrey A., and Anatoly V. Pogorelov. "PECULIARITIES OF KRASNODAR WATER RESERVOIR SILTING.EVALUATION BASED ON THE DATA OF BATHYMETRIC SURVEYS." Географический вестник = Geographical bulletin, no. 4 (2018): 54–66. http://dx.doi.org/10.17072/2079-7877-2018-4-54-66.

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Anzidei, M. "Rapid bathymetric surveys in marine volcanic areas: A case study in panarea area." Physics and Chemistry of the Earth, Part A: Solid Earth and Geodesy 25, no. 1 (January 2000): 77–80. http://dx.doi.org/10.1016/s1464-1895(00)00013-2.

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Atallah, Louis, and Penny Probert Smith. "How useful is bathymetric information in the classification of high frequency sonar surveys?" Journal of the Acoustical Society of America 116, no. 4 (October 2004): 2487. http://dx.doi.org/10.1121/1.4784932.

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Veselov, O. V., and D. N. Kozlov. "Geothermal and bathymetric surveys of Brouton Bay (Uratman Volcano, Simushir I., Kuril Islands)." Journal of Volcanology and Seismology 8, no. 4 (July 2014): 250–59. http://dx.doi.org/10.1134/s074204631404006x.

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Horta, J., A. Pacheco, D. Moura, and Ó. Ferreira. "Can recreational echosounder-chartplotter systems be used to perform accurate nearshore bathymetric surveys?" Ocean Dynamics 64, no. 11 (October 9, 2014): 1555–67. http://dx.doi.org/10.1007/s10236-014-0773-y.

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Molen, Wim van der, Holly Watson, and David Taylor. "ALLOWANCE FOR FORMATION OF MEGA SAND WAVES ON THE SEABED IN THE DESIGN OF FAIRWAYS IN ESTUARIES WITH STRONG CURRENTS." Coastal Engineering Proceedings, no. 36v (December 28, 2020): 35. http://dx.doi.org/10.9753/icce.v36v.sediment.35.

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The declared depth in port access channels is often maintained by dredging and monitored by regular bathymetric surveys. However, at remote sites these activities are not cost-effective and the channel depth would need to be defined based on the surveyed depth plus an allowance for sedimentation and variability in bed levels. This allowance can especially be significant in estuaries with strong tidal currents, where mega bedforms, including sand waves, develop on the seabed due to the prevailing strong current flows. The mega sand waves are highly mobile and fluctuate in height as they migrate over the seabed. Mega sand waves and mega ripples with a height up to approx. 3.2 m were observed in multi-beam bathymetric survey undertaken in the offshore entrance to the Geba River estuary in Guinea Bissau. Supramax bulk carriers with a draft of 11-12 m are planned to transit this area on departure from a proposed phosphate export terminal located further upstream in the estuary.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/5Gmy9yQkfno

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Specht, Mariusz, Cezary Specht, Maciej Szafran, Artur Makar, Paweł Dąbrowski, Henryk Lasota, and Piotr Cywiński. "The Use of USV to Develop Navigational and Bathymetric Charts of Yacht Ports on the Example of National Sailing Centre in Gdańsk." Remote Sensing 12, no. 16 (August 11, 2020): 2585. http://dx.doi.org/10.3390/rs12162585.

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Apart from extensive infrastructure protection, modern yacht ports should primarily provide vessels with navigational safety associated with their maneuvering on the approach fairway, as well as mooring in the port aquatory. For this reason, yachts entering the harbor should have up-to-date, accurate, and reliable charts of the port and its surroundings. This article presents hydrographic surveys conducted in the National Sailing Centre (NSC) yacht port at the Gdańsk University of Physical Education and Sport (GUPES), whose aim was to define and develop unique bathymetric and navigational charts of the harbor and the approach fairway. These can be used for example to manage berths in the marina or inform about the depths in the yacht port and on the approach fairway. The chart of the NSC-GUPES and its approach fairway is Poland’s first cartographic image of a harbor, performed entirely on the basis of surveys conducted by an Unmanned Surface Vehicle (USV). The study results demonstrated that the use of a small-sized USV in bathymetric measurements of yacht ports and marinas was significantly more effective than the traditional (manned) hydrographic surveys. Such vessels allow measurements to be carried out in hard-to-reach locations, even between mooring vessels, and in the immediate vicinity of quays. Thanks to the implemented automatic mode of steering on sounding profiles, USVs are equally efficient and capable of carrying out hydrographic surveys on a larger waterbody, i.e., the approach fairway.

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Cooper, A. P. R., J. L. Smellie, and J. Maylin. "Evidence for shallowing and uplift from bathymetric records of Deception Island, Antarctica." Antarctic Science 10, no. 4 (December 1998): 455–61. http://dx.doi.org/10.1017/s0954102098000558.

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Deception Island is a large volcanic centre in Bransfield Strait, a very young marginal basin between the South Shetland Islands and Antarctic Peninsula. It has a historical record of volcanic activity, with the most recent eruption occurring in 1970. The island is a stratovolcano with a large flooded caldera forming a natural harbour known as Port Foster. It has been a focus of human activity since early last century, as a base for whaling and sealing expeditions and the locus of several scientific stations. During that period, many bathymetric surveys were carried out, the earliest in 1829 and the most recent in 1993. This study concentrates on surveys from 1948 onwards. Because Port Foster can be classified as a restless caldera, the bathymetric records were analysed for evidence of volcano-tectonic deformation, particularly caldera resurgence (uplift) which could have significant consequences for hazard and risk assessments of the volcano. The results show that a distinctive pattern of shallowing and uplift is present, correlating well with known and inferred volcanic and volcanotectonic processes on the island. In particular, bathymetric records between 1949 and 1993 show uplift rates as high as 0.3–0.5 m a−1, far exceeding normal sedimentation rates in a caldera this size. Rapid uplift in an arcuate offshore area not affected by the sedimentation of recent eruptions suggests that volcano tectonic resurgence or tectono-magmatic effects of an upward migrating magma chamber present a significant risk to the considerable human activity taking place in the region.

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Norro, Alain, Georges Pichot, Virginie Pison, and José Ozer. "A bi-dimensional approach to assessing the volumetric evolution of an exploited sandbank." ICES Journal of Marine Science 63, no. 1 (January 1, 2006): 176–86. http://dx.doi.org/10.1016/j.icesjms.2005.08.006.

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Abstract We analyse the multi-annual evolution of bathymetry along several cross-sections of the Kwintebank (one of the Flemish Banks). An important issue in the area is the intensive exploitation under regulations imposed by the Belgian authorities that aim to guarantee sustainability of extractions. All bathymetric data collected during the period 1987–2000 at a frequency of approximately four surveys per year are analysed, to identify volumetric temporal trends. The errors inherent in the measurements taken with a single-beam instrument are examined. The lack of indisputable quality criteria led to the choice of robust statistical methods. A statistically significant annual decline of approximately 1.5% in bank volume is shown. Another practical conclusion is that a big increase in sampling frequency is necessary if the authorities set a criterion regarding the long-term sustainability of the bank and wish to have a swift guarantee that this criterion is being observed.

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Výleta, Roman, Peter Valent, and Zuzana Danáčová. "Monitoring Changes in the Morphology and Storage of a Small Water Reservoir: A Case Study from Vrbovce, Slovakia." Slovak Journal of Civil Engineering 28, no. 2 (June 1, 2020): 30–35. http://dx.doi.org/10.2478/sjce-2020-0012.

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AbstractOne of the most profound problems in the operation of water reservoirs is their siltation by sediments coming from agricultural land. The siltation of water reservoirs can significantly shorten their life spans and prevent them from effectively fulfilling their functions. Therefore, accurate monitoring of the current state and dynamics of siltation processes is critical to maintaining their economic, environmental, and societal functions. This study presents a simple method to evaluate the sedimentation rate of a small water reservoir in Slovakia. The method is based on comparing the results from two bathymetric surveys that were carried out in 2017 and 2019 using an ultrasonic acoustic doppler current profiler (ADCP), which was originally developed to measure river discharges. A raster map of the thickness of the sediment in the reservoir was assembled by subtracting the two bathymetric surveys from each other. The analysis of the results showed that the mean annual sedimentation rate of the reservoir is only 101 m3/year, representing a mean increment in sediment thickness of 1.4 cm. The method described showed promising results and could be applied to numerous small water reservoirs of a similar size across Slovakia.

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Ma, Teng, Ye Li, Yusen Gong, Rupeng Wang, Mingwei Sheng, and Qiang Zhang. "AUV Bathymetric Simultaneous Localisation and Mapping Using Graph Method." Journal of Navigation 72, no. 06 (July 5, 2019): 1602–22. http://dx.doi.org/10.1017/s0373463319000286.

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Although topographic mapping missions and geological surveys carried out by Autonomous Underwater Vehicles (AUVs) are becoming increasingly prevalent, the lack of precise navigation in these scenarios still limits their application. This paper deals with the problems of long-term underwater navigation for AUVs and provides new mapping techniques by developing a Bathymetric Simultaneous Localisation And Mapping (BSLAM) method based on graph SLAM technology. To considerably reduce the calculation cost, the trajectory of the AUV is divided into various submaps based on Differences of Normals (DoN). Loop closures between submaps are obtained by terrain matching; meanwhile, maximum likelihood terrain estimation is also introduced to build weak data association within the submap. Assisted by one weight voting method for loop closures, the global and local trajectory corrections work together to provide an accurate navigation solution for AUVs with weak data association and inaccurate loop closures. The viability, accuracy and real-time performance of the proposed algorithm are verified with data collected onboard, including an 8 km planned track recorded at a speed of 4 knots in Qingdao, China.

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Firsov, Yury G. "SPECIAL NAVIGATIONAL SUPPORT AND ACCURACY OF BATHYMETRIC SURVEYS FOR DEEP-SEA MARINE GEOLOGICAL INVESTIGATIONS." Vestnik Gosudarstvennogo universiteta morskogo i rechnogo flota imeni admirala S. O. Makarova 11, no. 6 (December 28, 2019): 1070–87. http://dx.doi.org/10.21821/2309-5180-2019-11-6-1070-1087.

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Rowan, J. S., P. Goodwill, and M. Greco. "Temporal variability in catchment sediment yield determined from repeated bathymetric surveys: Abbeystead Reservoir, U.K." Physics and Chemistry of the Earth 20, no. 2 (April 1995): 199–206. http://dx.doi.org/10.1016/0079-1946(95)00024-0.

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Quinn, Rory, and Donal Boland. "The role of time-lapse bathymetric surveys in assessing morphological change at shipwreck sites." Journal of Archaeological Science 37, no. 11 (November 2010): 2938–46. http://dx.doi.org/10.1016/j.jas.2010.07.005.

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Herzfeld, Ute Christina. "Geostatistical methods for evaluation of Seabeam bathymetric surveys: Case studies of Wegener Canyon, Antarctica." Marine Geology 88, no. 1-2 (July 1989): 83–95. http://dx.doi.org/10.1016/0025-3227(89)90006-6.

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Byrne, Shannon, Brian Clifford, Walter Simmons, Jan Depner, Barbara Reed, Jenny Moestikiwati, and Gail Smith. "Processing Data for Seafloor Mapping: Integration and Metrics." Marine Technology Society Journal 35, no. 4 (December 1, 2001): 20–32. http://dx.doi.org/10.4031/002533201788058017.

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Today's state-of-the-art hydrographic survey instrumentation produces higher resolution and more densely sampled measurements than were available in the past. This supports improvements in the definition of seafloor features and characteristics, however, it also places more stringent requirements on the systems used to process seafloor survey data. In shallow water environments bathymetric sampling rates can exceed 4000 soundings per second and data from Digital Side-Scan Sonar Systems can exceed 1 Gb/hr. In support of the Second International Conference on High-Resolution Surveys in Shallow Water, and working in cooperation with Reson Inc., Goleta, Ca., and the University of New Hampshire's Center for Coastal and Ocean Mapping (CCOM), Science Applications International Corporation (SAIC), Newport, RI conducted a survey of the conference common data set test area in Portsmouth Harbor using a Reson 8125 dual-head sonar system. The acquired data were made available as part of the conference common dataset. An area-based approach to data cleaning, including the use of an automated filter for spike detection, is presented. Resource and effort metrics associated with the processing of samples from the common data set are provided. This includes corrector application, data cleaning, validation, and quality control. Results from the area-based approach are compared with results from a traditional line-oriented approach. Three bathymetric datasets from Portsmouth Harbor are compared and the results reported.

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Mikuška, Ján, Roman Pašteka, and Ivan Marušiak. "Estimation of distant relief effect in gravimetry." GEOPHYSICS 71, no. 6 (November 2006): J59—J69. http://dx.doi.org/10.1190/1.2338333.

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We analyze gravitational effects of distant topographic and bathymetric relief beyond the (earth-centered) angular distance of [Formula: see text] (i.e., beyond the outer limit of the Hayford-Bowie zone O, or approximately [Formula: see text]) using a spherical earth model. Our results support current procedures that neglect distant relief effects for most local gravity surveys but show their potential importance for continental- and global-scale surveys. The distant relief can produce horizontal gradients as large as [Formula: see text] [Formula: see text]. In mountainous areas, the gravitational effect of the distant relief is significant, even for local surveys, although the vertical gradient of the distant relief effect never exceeds [Formula: see text] [Formula: see text] on the earth’s surface.

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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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Kapetanović, Nadir, Branko Kordić, Antonio Vasilijević, Đula Nađ, and Nikola Mišković. "Autonomous Vehicles Mapping Plitvice Lakes National Park, Croatia." Remote Sensing 12, no. 22 (November 10, 2020): 3683. http://dx.doi.org/10.3390/rs12223683.

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Plitvice Lakes National Park is the largest national park in Croatia and also the oldest from 1949. It was added to the UNESCO World Natural Heritage List in 1979, due to the unique physicochemical and biological conditions that have led to the creation of 16 named and several smaller unnamed lakes, which are cascading one into the next. Previous scientific research proved that the increased amount of dissolved organic matter (pollution) stops the travertine processes on Plitvice Lakes. Therefore, this complex, dynamic but also fragile geological, biological and hydrological system required a comprehensive limnological survey. Thirteen of the sixteen lakes mentioned above were initially surveyed from the air by an unmanned aircraft equipped with a survey grade GNSS and a full frame high-resolution full-screen camera. From these recordings, a georeferenced, high-resolution orthophoto was generated, on which the following surveys by a multibeam sonar depended. It is important to mention that this was the first time that these lakes had ever been surveyed both with the multibeam sonar technique and with such a high-resolution camera. Due to the fact that these thirteen lakes are difficult to reach and often too shallow for a boat-mounted sonar, a special autonomous surface vehicle was developed. The lakes were surveyed by the autonomous surface vehicle mounted with a multibeam sonar to create detailed bathymetric models of the lakes. The missions were planned for the surface vehicle based on the orthophoto from the preliminary studies. A detailed description of the methodology used to survey the different lakes is given here. In addition, the resulting high-resolution bathymetric maps are presented and analysed together with an overview of average, maximum depths and number of data points. Numerous interesting depressions, which are phenomena consistent with previous studies of Plitvice Lakes, are noted at the lake beds and their causes are discussed. This study shows the huge potential of remote sensing technologies integrated into autonomous vehicles in terms of much faster surveys, several orders of magnitude more data points (compared to manual surveys of a few decades ago), as well as data accuracy, precision and georeferencing.

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Tlusty, Michael F., John E. Hughes Clark, John Shaw, Vem A. Pepper, and M. Robin Anderson. "Groundtmthing Multibeam Bathymetric Surveys of Finfish Aquaculture Sites in the Bay d’Espoir Estuarine Fjord, Newfoundland." Marine Technology Society Journal 34, no. 1 (January 1, 2000): 59–67. http://dx.doi.org/10.4031/mtsj.34.1.7.

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Current and potential salmonid aquaculture sites in the Bay d’Espoir estuarine fjord on the south coast of Newfoundland were surveyed using multibeam SWATH sonar. In 1997, shallow sites were surveyed using the CSS Puffin EM3000POS/MV system, and deeper sites were surveyed in 1998 using the CCGS Creed hull mounted EM 1000. Sediment cores from representative areas were collected during this period and analyzed for organic matter content, and pore water ammonium and sulfate. We discuss the correlation between the sediment core profiles and the results of the side scan and sun-illuminated bathymetric imagery. Bay d’Espoir is a natural depositional area, and that, coupled with the unique backscatter properties of fish farm wastes, increases the difficulty of interpreting these multibeam sonar images. A fairly accurate broad scale characterization of sediment quality can be made from high-resolution images. However’, much of the fine scale detail and inherent variation of sediment characteristics associated with impacts from aquaculture cannot be determined from multibeam imagery.

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Salem, Mohamed. "Study of Conrad and Shaban deep brines, Red Sea, using bathymetric, parasound and seismic surveys." NRIAG Journal of Astronomy and Geophysics 6, no. 1 (June 2017): 90–96. http://dx.doi.org/10.1016/j.nrjag.2017.04.003.

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Journal articles on the topic 'Bathymetric surveys'

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