scholarly journals High-resolution multibeam sonar for subsea leakage detection

2013 ◽  
Author(s):  
Gorm Wendelboe ◽  
Simon Barchard ◽  
Eric Maillard ◽  
Leif Bjorno
Keyword(s):  
High Resolution ◽  
Leakage Detection ◽  
Multibeam Sonar

scholarly journals Negative Pressure Waves Based High Resolution Leakage Localization Method Using Piezoceramic Transducers and Multiple Temporal Convolutions

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 1990 ◽  
Author(s):  
Guangmin Zhang ◽  
Siu Chun Michael Ho ◽  
Linsheng Huo ◽  
Junxiao Zhu
Keyword(s):  
High Resolution ◽  
Lead Zirconate Titanate ◽  
Negative Pressure ◽  
Lead Zirconate ◽  
Signal Duration ◽  
Leakage Detection ◽  
Localization Algorithm ◽  
Large Area ◽  
Leakage Area ◽  
Better Than

The negative pressure wave (NPW) signals generated by a pipeline leakage often have a long signal duration. When these signals are utilized to compute the leakage position, the long signal duration will result in a large area being considered as leakage area. The localization resolution is low. A novel high-resolution localization algorithm is developed for pipeline leakage detection using piezoceramic transducers in this paper. The proposed algorithm utilizes multiple temporal convolutions to decrease the localization functional values at the points close to the leakage, in order to reduce the range of the leakage area revealed by the proposed algorithm. As a result, the localization resolution is improved. A measured experiment was conducted to study the proposed algorithm. In the experiment, the proposed algorithm was used to monitor a 55.8 m pressurized pipeline with two controllable valves and two Lead Zirconate Titanate (PZT) sensors. With the aid of the piezoceramic sensor, the experimental results show that the proposed algorithm results in a resolution which is better than that of the traditional method.

Management and analysis of high resolution multibeam sonar surveys for geometry characterization of riverbed material

2020 ◽  
Author(s):  
Simone Rover ◽  
Gabriele Avancini ◽  
Alfonso Vitti
Keyword(s):  
High Resolution ◽  
Survey Methods ◽  
High Water ◽  
Quantitative Information ◽  
Water Levels ◽  
Geometric Characterization ◽  
Innovative Technology ◽  
Multibeam Sonar ◽  
Surface Models

<p>The geometric characterization of riverbed material is fundamental piece of information for the management of river basins because it allows, for example, the determination of bed-load and hydrodynamics roughness and the study of geo-morphological phenomenona.<br>However information such the grading curve are not easily achievable by means of traditional field sampling methods, mostly intrusive, and to the hydraulic conditions of rivers that may have high water levels and strong flows.</p><p>Multibeam sonars represent an important alternative to traditional survey methods. Nowadays, thanks to advanced scientific knowledge, it is possible to make full use of an equipment increasingly accurate and precise. State of the art solutions have dimensions compact enough to be installed on remotly piloted vehicles and allow to obtained high resolution digital surface models of river beds. The feasibility of having models of such quality and the possibility to conduct surveys more frequently, allowing the monitoring of sedimentation and erosion phenomena as well as the dynamics of the armouring layer, have motivated the development of advanced and innovative technology to analyse these models.</p><p>The aim of this work is the development of a workflow that provides an effective method to characterize riverbed material. In order to achieve this target we start from an advanced and original survey technique, that allows to obtain high resolution digital surface models, and use an appropriate post-processing procedure.<br>We introduce first some results obtained from the analysis of digital surface models produced in laboratory or relative to well known site. In particular advanced techniques for the study of 3D model and the detection and geometric characterization of forms are investigated.<br>Then we present some data acquired at high resolution (few centimeters) with a multibeam sonar mounted on a remote controlled vessel. Field surveys were conducted in real fluvial environment with the aim of produce qualitative and quantitative information about the surface layer of riverbed.<br>Even considering some sources of uncertainty that may be present from field survey to modeling, the obtained results show how it is possible to identify and geometrically characterize several of the forms present on the surfaces analyzed. </p>

scholarly journals Discriminating between Posidonia oceanica meadows and sand substratum using multibeam sonar

2010 ◽  
Vol 68 (1) ◽  
pp. 12-19 ◽  
Author(s):  
Germana Di Maida ◽  
Agostino Tomasello ◽  
Filippo Luzzu ◽  
Antonino Scannavino ◽  
Maria Pirrotta ◽  
...  
Keyword(s):  
High Resolution ◽  
Classification Accuracy ◽  
Posidonia Oceanica ◽  
Automated Classification ◽  
Multibeam Sonar ◽  
Discriminating Power ◽  
Beam Depth ◽  
Seabed Mapping ◽  
Sandy Substratum

Abstract Di Maida, G., Tomasello, A., Luzzu, F., Scannavino, A., Pirrotta, M., Orestano, C., and Calvo, S. 2011. Discriminating between Posidonia oceanica meadows and sand substratum using multibeam sonar. – ICES Journal of Marine Science, 68: 12–19. High-resolution, multibeam sonar (MBS) (455 kHz) was used to identify two typologies of seabed 8 m deep: Posidonia oceanica meadow and sandy substratum. The results showed that the heterogeneity of the architecture of the P. oceanica canopy and the relatively simple morphology of a sandy substratum can be detected easily by statistical indices such as standard deviation or range-of-beam depth. Based on these indices, an automated classification was performed for seabed mapping. The overall classification accuracy was as high as 99 and 98% in October and January, respectively. The probability that P. oceanica in situ was omitted on the map was <7%, whereas the probability that an area classified as P. oceanica on the map did not correspond to the seagrass in situ was consistently negligible. Based on these results, high-resolution MBS can be considered to be an accurate tool for mapping P. oceanica and sand substrata, and its discriminating power seems to be independent of season (autumn or winter).

Predictive mapping of seabed substrata using high-resolution multibeam sonar data: A case study from a shelf with complex geomorphology

2014 ◽  
Vol 357 ◽  
pp. 37-52 ◽  
Author(s):  
Huang Zhi ◽  
Justy Siwabessy ◽  
Scott L. Nichol ◽  
Brendan P. Brooke
Keyword(s):  
High Resolution ◽  
Predictive Mapping ◽  
Multibeam Sonar

Visualizing Samsonfish (Seriola hippos) with a Reson 7125 Seabat multibeam sonar

2013 ◽  
Vol 70 (3) ◽  
pp. 665-674 ◽  
Author(s):  
Miles J. G. Parsons ◽  
Iain M. Parnum ◽  
Robert D. McCauley
Keyword(s):  
High Resolution ◽  
Western Australia ◽  
Avoidance Behaviour ◽  
Acoustic Backscatter ◽  
Marine Science ◽  
Nearest Neighbour ◽  
Multibeam Sonar ◽  
Neighbour Distance ◽  
Habitat Features

Abstract Parsons, M. J. G., Parnum, I. M., and McCauley, R. D. 2013. Visualizing Samsonfish (Seriola hippos) with a Reson 7125 Seabat multibeam sonar – ICES Journal of Marine Science, 70: 665–674. In Western Australia, aggregations of Samsonfish (Seriola hippos) form each summer to spawn in waters west of Rottnest Island. In this study, a Reson 7125 Seabat multibeam sonar (400 kHz) was pole mounted aboard a 21.6 m vessel, conducting acoustic transects to acquire acoustic backscatter simultaneously from a midwater aggregation of S. hippos and the wreck it surrounded. The processed backscatter produced high-resolution visualizations of both the fish and seabed. During a 15 min period, the centroid of the aggregation moved 91 m around the eastern and northeastern side of the wreck and probably exhibited lateral vessel avoidance behaviour from the survey vessel. Additionally, a northeasterly current at the site was inferred from subtle habitat features, suggesting that at the time of the survey the aggregation preferred to remain upcurrent of the wreck. These findings confirmed that the S. hippos aggregations do not necessarily remain directly above the wrecks and do not always remain sedentary. Aggregation acoustic density packing at the survey site was observed at 12.7 ± 2.4 m3 per fish, equivalent to ∼1.6 ± 0.1 body lengths nearest-neighbour distance.

Underwater pipeline leakage detection via multibeam sonar imagery

2017 ◽  
Vol 141 (5) ◽  
pp. 3917-3917 ◽  
Author(s):  
Wanyuan Zhang ◽  
Tian Zhou ◽  
Dongdong Peng ◽  
Jiajun Shen
Keyword(s):  
Leakage Detection ◽  
Multibeam Sonar ◽  
Underwater Pipeline

scholarly journals Autonomous Vehicles Mapping Plitvice Lakes National Park, Croatia

2020 ◽  
Vol 12 (22) ◽  
pp. 3683
Author(s):  
Nadir Kapetanović ◽  
Branko Kordić ◽  
Antonio Vasilijević ◽  
Đula Nađ ◽  
Nikola Mišković
Keyword(s):  
High Resolution ◽  
Autonomous Vehicles ◽  
National Park ◽  
Unmanned Aircraft ◽  
Multibeam Sonar ◽  
Autonomous Surface Vehicle ◽  
Average Maximum ◽  
Hydrological System ◽  
Data Points ◽  
Plitvice Lakes

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.

scholarly journals Dam Leakage Detection by Borehole Radar: A Case-History Study

2019 ◽  
Vol 11 (8) ◽  
pp. 969 ◽  
Author(s):  
Sixin Liu ◽  
Xudong Wang ◽  
Qi Lu ◽  
Honqing Li ◽  
Yuanxin Wang ◽  
...  
Keyword(s):  
High Resolution ◽  
Internal Erosion ◽  
Leakage Detection ◽  
Low Velocity ◽  
Dam Foundation ◽  
Concrete Walls ◽  
Single Hole ◽  
Reflection Profile ◽  
Borehole Radar ◽  
Water Saturated

A borehole radar investigation was performed at the Sanzuodian reservoir, Chifeng, China to assess possible leakage paths located in the deep dam foundation. The key methodologies used include both single-hole reflection and cross-hole radar tomography, which make a high-resolution identification of the hydraulic connection paths between upstream and downstream sides possible. The leakage paths are characterized by direct wave loss due to high electromagnetic attenuation in the single-hole reflection profile and the nearly horizontal-banded low-velocity zone in the cross-hole velocity tomography due to possible large internal erosion. Meanwhile, some small structures inside the dam, including the core wall thickness changing point, the connecting point between asphalt and concrete walls, and the contacting interface between the dry and the water-saturated formations can be identified from the single-hole reflection profile clearly. Interpreted leakage paths are proven by the water flow measurement. Borehole radar is a useful high-resolution tool, suitable for deep leakage detection and evaluation.

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