Multibeam Bathymetric System Research Articles

Research on survey line arrangement of a multibeam bathymetric system in ocean mapping

Submarine topography measurement technology is an important technology for exploring marine resources. Multi-beam bathymetry systems have high efficiency and important application value in underwater resource surveys, marine delimitation, and other fields. They are currently one of the most widely used measurement technologies. This study aims to optimize multi-beam bathymetry technology and apply it to seabed topography measurement, achieving a transition from point measurement to line measurement and minimizing measurement paths. A mathematical model was established for the coverage width and overlap rate between adjacent bands of multi-beam bathymetry at a given water depth based on planar geometric modeling and three-dimensional geometric modeling. The model was applied to a rectangular sea area with a length of 2 nautical miles (3704 meters) from north to south and a width of 4 nautical miles (7408 meters) from east to west. The optimal survey line planning was obtained as follows: all survey lines are in the north-south direction, with a total of 34 survey lines and a total length of 68 nautical miles. This model has good solution results for optimizing the layout of survey lines under different seabed conditions and can adjust important parameters of the system according to different conditions. The model has broad practical significance and can provide a reference for ocean-sounding work and other fields with high accuracy.

A Study of Multibeam Line Measurement Problems Based on Analytic Geometry and Mechanistic Analysis

Based on the important application of multibeam bathymetric systems in marine science and engineering, this study explores their working principle and application potential. Through the establishment of a mathematical model, problems such as coverage width and distance between survey lines are solved, and an optimized survey line layout scheme is proposed. For the seabed topography data, combined with geometric analysis and visualization technology, accurate measurement and analysis of seabed topography is realized, which provides important support for marine survey, resource exploration and underwater engineering. The research results are of guiding significance for the further development and application of multibeam bathymetry technology and provide strong support for research and practice in related fields.

Optimal modeling of line paths based on multibeam bathymetric system

Multibeam ocean bathymetry is one of the major issues in exploring the ocean. For problems such as multibeam line ocean bathymetry, this paper starts from the related theory, analyzes the inherent geometric features of the problem, comprehensively establishes a multibeam line model with generalized significance within a certain error range, and according to the method of least squares, gives a model of the line with a fixed opening angle of the multibeam transducer in a certain range of the sea area. Firstly, from the geometrical point of view, the interpreted diagram and the schematic diagram given in the title are combined and simplified into a problem of solving a triangle. The trigonometric equations are listed through the sine theorem and solved algebraically. A mathematical model is developed about the coverage width and adjacent strips. Then, from the question, we know that we need to solve the modeling differences caused by the different angles of the measuring lines in different directions, i.e., to elevate the two-dimensional problem of solving triangles to a three-dimensional problem of three-dimensional geometry. By finding the angle between the coverage width and the horizontal plane , we know the relationship between it and the angle between the direction of the survey line and the slope angle , so as to establish the model of the coverage width of multibeam bathymetry. Summarized by the verification of the previous conclusions, this paper obtains: when controlling the width of two adjacent survey lines exactly meets the overlap rate of 10% with the previous survey line, and the survey line direction is perpendicular to the seafloor slope in the projection, the measurement length is the shortest at this time. Using the above summary as a constraint, the shortest path is calculated to be 66 nautical miles using the trigonometric method.

The study of the direction of navigation of ships in a particular sea area

Multibeam bathymetric system is a further development of single-beam bathymetric system, which can send and receive hundreds of beams at the same time during the working process, and carry out full-coverage bathymetric strip measurements in the smooth sea area on the seabed. In this paper, we model the coverage width and the overlap rate to further reduce the errors occurring in the measurement process, and at the same time, we design a scheme for the given data and constraints to solve the practical problems. The process analysis facilitates the practical application of multibeam bathymetry system, improves the problems of failing to achieve the full coverage of the sea area and the high overlap rate, and provides a new idea for the seabed detection of multibeam bathymetry.

Study and Application of Optimization Model on Survey Line under Multibeam Bathymetric System

In this paper, the definition of overlap rate is deduced so as to clarify the influence of overlap rate between the horizontal plane and the slope on the multibeam line measurement problem, and the artificial correction is calculated by taking the average value of the coverage widths of the two times before and after. The expressions for the coverage widths of different lines and their corresponding water depths, slope inclination angles, and transducer opening angles are derived from the functional relationship by combining numerical and morphological methods. The resulting expression of the coverage width W was corrected, averaged and brought into the definition of the overlap rate, resulting in the final expression to calculate the corresponding value, and the resolution and accuracy of the data results were high.

Model-Driven Multibeam Line Measurement System Design

Multibeam bathymetric system is a complex combination of multi-sensor system. The multibeam bathymetric system is mainly used in the measurement of water depth of waterways, and the scientific layout of the survey line can improve the measurement efficiency, and at the same time, truly and perfectly reflect the topography of the waterway. This paper establishes a mathematical model of coverage width and overlap rate between adjacent strips for multibeam bathymetry, and calculates the parameters such as water depth, coverage width and overlap rate between adjacent strips at the center point of different survey lines. Firstly, a single slope multibeam line model was established to calculate the coverage width and the overlap rate between adjacent strips of the multibeam bathymetric system, taking into account the influence of the slope of a single slope. Then, considering the influence of the angle between the direction of the survey line and the projection of the normal direction of the seafloor slope on the horizontal plane, a mathematical model of multibeam bathymetry with variable survey line direction is established by downscaling the geometrical relationship in the three-dimensional space to the two-dimensional plane. Again, based on the principle of line design, all the lines with overlap rate between 10% and 20% are comprehensively screened, and the enumeration method is adopted to find out the optimal lines under each group of conditions. Finally, a three-dimensional seabed model is constructed based on the actual sea depth data, and the optimal measurement direction and spacing of the survey lines are determined based on the real seabed topographic features, which achieves the goal of minimizing the length of the survey lines, and at the same time, ensures that the survey lines can cover the entire sea area to be surveyed, and the iterative method is used to search for the final direction of the survey lines and find the optimal solution.

Research on Multibeam Bathymetric System Based on Geometrical Relation Mo Model

In this paper, the basic principles of multibeam bathymetry system are discussed in depth, the development of which originates from the single-beam bathymetry technology. Through profound mathematical modelling and geometric relationship derivation, a systematic and detailed analysis is carried out for the coverage width of multibeam bathymetry and the overlap rate between two adjacent bands in the case that the survey line is parallel to the horizontal plane. Adopting the idea of combining numbers and shapes, combined with the triangle side angle relationship, we established a geometrical-mathematical model with an α-slope slant line, which lays a solid theoretical foundation for solving the problem. In this study, we successfully solved the expression of seawater depth D of the multibeam bathymetric system in the case that the direction of the survey line is parallel to the horizontal plane by the method of listing relations. At the same time, we make full use of the sine-cosine theorem of triangles to derive the coverage width of the bathymetric strip in depth. Combining these two organically, a complete and detailed expression for the coverage width is formed, which provides a powerful mathematical tool for the further study of deep-sea bathymetry technology. In addition, by applying the mathematical model to the vacant data in Table 1, we successfully fill in this missing information, demonstrating the feasibility and accuracy of the model in practical applications. This study not only makes remarkable progress in theory, but also provides strong support for practical applications in the field of ocean bathymetry.

Optimization Model of Survey Line Layout for Multibeam Bathymetric Systems

Multibeam bathymetric system is an underwater terrain measurement technology with high efficiency, high accuracy and high resolution. Based on the multibeam bathymetric system, this paper establishes an ideal geometric model and an isobath iterative model. Through the physical method of ideal model, the actual physical problem of multibeam sounding is abstracted into a geometric model about a conic curve, and under the constraint of overlap rate, the coordinates of the next survey line are iterated according to the current depth to solve the optimal set of survey lines. First, the seawater depths, strip coverage widths, and overlap rates with the previous line are calculated for lines at different distances from the center point. Then, the angle between the direction of the survey line and the projection of the normal direction of the seafloor slope on the horizontal plane is introduced to solve for the current coverage width of the survey line. Again, the optimal set of survey lines is solved under the constraint of the overlap rate. Finally, Sobel edge detection is used to divide the surface of the seafloor terrain into multiple planes with defined slope angles to solve the optimal line set for the entire seafloor surface. The structure of the proposed mathematical model is clear and simple, which is in line with the actual situation.

Preliminary study regarding the positioning of the bathymetric system on a research ship

The topic of this preliminary study comes from the need to analyze the positioning of the multi-beam bathymetric system on a research vessel on the Danube River. Starting from the variants of bathymetric echo sound systems, they were discussed in advance with the supplying company and the construction shipyard to ensure the most advantageous cases of positioning the bathymetric equipment. The results of this preliminary study provide the researchers and the shipyard with several options for positioning the bathymetric system to choose a constructive solution that will ensure the requested operation conditions for recording the most relevant waterways bathymetric data regarding the safety of navigable channels on the Danube River.

Morphosedimentological features of the sea floor in the outer sector of the Bahia Blanca estuary, Argentina

The purpose of this paper is to analyze the morphology of the Quaternary relict features and bedforms that characterize the outer zone of an extensive mesomareal system, which is part of the Bahía Blanca estuary (Argentina), and to estimate the prevailing hydro-sedimentological conditions on the continental shelf adjacent to the estuary. Surveys with a multibeam bathymetric system, side-scan sonar and a high-resolution seismic system (3.5 kHz) were carried out and bottom sediment samples were collected. In general, the seafloor presents a varied configuration, marked by changes in its physiography. The Quaternary relict features are composed of two terraces (12–14 m and 18–22 m deep), with steeply sloping escarpments, that are oriented approximately parallel to the current coastline. Associated with these terraces, wide abrasion platforms develop with irregular and plateau-like structures up to 4 m high, together with large rocky blocks up to 6 m in diameter. Here, the predominant sediment corresponds to a gravel-sized material composed of quartzite boulders, siltstone fragments of up to 7 cm, and biogenic remains with different degrees of fragmentation. These sedimentological data, together with the bathymetric and seismostratigraphic information, indicate that the terraces and abrasion platforms are ancient shorelines that originated in an environment with high wave energy, corresponding to periods of stabilization of sea level rise during the final stage of the last postglacial transgression (late Pleistocene-Early Holocene). On the other hand, asymmetric dunes of different sizes (0.5 m < height < 5 m, 5 m < wavelength < 200 m), sand ribbons (length > 300 m) and comet marks originated in equilibrium with the present-day hydro-sedimentological conditions. The availability of sandy material mobilized as bedload is the determining factor for the generation of the varied bedforms. Thus, sand ribbons and comet marks are generated especially in the northern sector of the area, with mobile sediment thicknesses ≤ 0.5 m. With larger thicknesses the formation of dunes occurs. Their size and asymmetry show an intense transport of sand as bedload towards the continental shelf, the southern sector of the area being the main route of the sediment that leaves the estuary. This sediment is the supply source of the sandy shoals that are part of the great ebb delta developed on the continental shelf in the external area of the Bahía Blanca estuary.

Comparison of multi-beam bathymetric system and 3D sonar system in underwater detection of beach obstacles

The instrument detection methods of underwater part of beach obstacle mainly include multi-beam bathymetric system and three-dimensional panoramic imaging sonar system. SeaBat T50-P multi beam bathymetry and BV5000-1350 sonar system are widely used in the area of underwater detection. The underwater part of beach obstacles is measured and analyzed, and the application scope of both equipment is discussed. The results show that the BV5000-1350 sonar system can be used to detect underwater incomplete obstacles with wider application scope, high accuracy, convenient installation of instruments, and no auxiliary equipment such as navigation, positioning and attitude sensor is needed; SeaBat T50-P multi-beam bathymetric system has high requirements for the structure of the measured object, moderate accuracy, and is more suitable for large-scale underwater obstacle survey.

Comprehensive Application of Multi-beam Sounding System and Side-scan Sonar in Scouring Detection of Underwater Structures in Offshore Wind Farms

In recent years, the installed capacity and power generation of offshore wind power have continued to grow rapidly, operation and maintenance testing has faced many technical challenges. Among them, the monitoring of the scour status of the underwater structure of the wind turbine and the complete basic data of the wind turbine's full life cycle management system are of great significance to ensuring the long-term safe and stable operation of the offshore wind farm. This paper introduces the application of a combined multi-beam bathymetric system and side-scan sonar in the scour detection of underwater structures of wind farms based on an example of offshore wind farm detection in the East China Sea. The combination of the two can effectively achieve complementary advantages and obtain more detailed and accurate water depth data and underwater structure images. It provides reliable basic data support for the operation and maintenance of offshore wind farms and the establishment of life cycle management system.

Application of Side Scan Sonar Simulation Technology in Submarine Sediment Classification

In the aspect of seafloor sediment detection, underwater acoustic method has been concerned and used because of its high working efficiency and continuous abundance of data, and the processing function of echo intensity data is to obtain backscattering intensity data which only reflect the change of seafloor sediment. However, relying solely on multi-beam bathymetric system or scanning Sonar will lead to awkward situations where the resolution is insufficient or topographic factors affect the effective removal. In this paper, the purpose of this paper is to reconstruct the sound intensity of side scan sonar in the same area by using the seafloor terrain data obtained by multi-beam bathymetric survey, and then to form a sonar image which eliminates the influence of terrain. This paper discusses how to deal with the directional scattering intensity data of many kinds of data sources, such as multi-beam bathymetric system and scanning Sonar, so as to provide a service for the effective classification of seafloor sediment.

A field investigation on the effects of background erosion on the free span development of a submarine pipeline

The safety of submarine pipelines is largely influenced by free spans and corrosions. Previous studies on free spans caused by seabed scours are mainly based on the stable environment, where the background seabed scour is in equilibrium and the soil is homogeneous. To study the effects of background erosion on the free span development of subsea pipelines, a submarine pipeline located at the abandoned Yellow River subaqueous delta lobe was investigated with an integrated surveying system which included a Multibeam bathymetric system, a dual-frequency side-scan sonar, a high resolution sub-bottom profiler, and a Magnetic Flux Leakage (MFL) sensor. We found that seabed homogeneity has a great influence on the free span development of the pipeline. More specifically, for homogeneous background scours, the morphology of scour hole below the pipeline is quite similar to that without the background scour, whereas for inhomogeneous background scour, the nature of spanning is mainly dependent on the evolution of seabed morphology near the pipeline. Magnetic Flux Leakage (MFL) detection results also reveal the possible connection between long free spans and accelerated corrosion of the pipeline.

Review of AUV Underwater Terrain Matching Navigation

Underwater terrain matching navigation technology is an important research area for the underwater navigation of Autonomous Underwater Vehicles (AUVs). Terrain matching navigation can realise long-term, subtle, all-weather, and high-precision underwater AUV navigation. In this paper, the research status of the application of AUV underwater terrain matching navigation is reviewed, the system composition, theory and terrain matching methods of underwater terrain matching navigation are summarised and the advantages of a multi-beam bathymetric system in underwater terrain matching navigation are discussed. The current research thoughts are summarised, the key issues are pointed out, and possible future development trends are discussed.

A new method for weakening the combined effect of residual errors on multibeam bathymetric data

Multibeam bathymetric system (MBS) has been widely applied in the marine surveying for providing high-resolution seabed topography. However, some factors degrade the precision of bathymetry, including the sound velocity, the vessel attitude, the misalignment angle of the transducer and so on. Although these factors have been corrected strictly in bathymetric data processing, the final bathymetric result is still affected by their residual errors. In deep water, the result usually cannot meet the requirements of high-precision seabed topography. The combined effect of these residual errors is systematic, and it’s difficult to separate and weaken the effect using traditional single-error correction methods. Therefore, the paper puts forward a new method for weakening the effect of residual errors based on the frequency-spectrum characteristics of seabed topography and multibeam bathymetric data. Four steps, namely the separation of the low-frequency and the high-frequency part of bathymetric data, the reconstruction of the trend of actual seabed topography, the merging of the actual trend and the extracted microtopography, and the accuracy evaluation, are involved in the method. Experiment results prove that the proposed method could weaken the combined effect of residual errors on multibeam bathymetric data and efficiently improve the accuracy of the final post-processing results. We suggest that the method should be widely applied to MBS data processing in deep water.

Determination of precise instantaneous height at multibeam transducer

To overcome the shortcomings of the traditional multibeam survey and data processing, a new method is presented for the precise determination of the instantaneous height at the multibeam transducer by the blend of GPS height and heave signals. Before signal blend, GPS height and heave signals need to be corrected first to the transducer center by attitude correction. Second, the GPS height needs to be checked and modified by heave check and modification itself. Butterworth and FFT (fast Fourier transformation) were used in the signal blend. Finally, FFT is thought to be appropriate in signal processing. The new method efficiently overcomes the shortcomings of the traditional method, and this is proven well by the MBS (multibeam bathymetric system) experiment.

Geologic Structure and Hydrodynamics of Egmont Channel: An Anomalous Inlet at the Mouth of Tampa Bay, Florida

Abstract High-resolution bathymetry surveys of Egmont Channel were conducted in 1999 and 2001 using a Kongsberg Simrad EM 3000 multibeam bathymetric system. These data were supplemented with other bathymetry data, seismic profiles, underwater scuba observations, and current velocity data, in order to investigate the geologic and hydrodynamic characteristics of Egmont Channel. Bounded to the north by a linear steep scarp (∼38°) and by a more gradual slope (>10°) to the south Egmont Channel is an asymmetric tidal inlet and the main shipping channel for Tampa Bay, Florida. The cross sectional area (17,964 m2) and the tidal prism (6×108 m3) for Egmont Channel were derived in this study. Currents measured at Egmont Deep and the Sunshine Skyway Bridge (∼11 km away) with Acoustic Doppler Current Profilers, have a high correlation (97%) indicating the current velocities at Sunshine Skyway Bridge can be used as a proxy for current velocities at Egmont Deep. Seismic profile data indicate that both the mouth of Tamp...

Precise Multibeam Acoustic Bathymetry

The maximum error in ocean depth measurement as specified by the International Hydrographic Organization is 1% for depth greater than 30m. Current acoustic multibeam bathymetric systems used for depth measurement are subject to errors from various sources which may significantly exceed this limit. The lack of sound speed profiles may be one significant source of error. Because of the limited ability of sound speed profile measurement, depth values are usually estimated using an assumed profile. If actual sound speed profiles are known, depth estimate errors can be corrected using ray-tracing methods. For depth measurements, the calculation of the location at which a sound pulse impinges on the sea bottom varies with the variation of the sound speed profile. We demonstrate that this location is almost unchanged for a family of sound speed profiles with the same surface value and the same area under them. Based on this observation, we can construct a simple constant-gradient equivalent sound speed profile to correct errors. Compared with ray-tracing methods, the equivalent sound speed profile method is more efficient. If a vertical depth is known (or independently measured), then depth correction for a multibeam system can be accomplished without knowledge of the actual sound speed profile. This leads to a new type of precise acoustic multibeam bathymetric system.