Multi-beam measuring line layout and data acquisition preprocessing method and system

Abstract

The invention discloses a multi-beam survey line layout and data acquisition preprocessing method and system, and the method comprises the steps: dividing a to-be-monitored river basin into a plurality of rectangular monitoring regions formed by main survey lines in a multi-beam survey line layout direction parallel to the direction of an isobath, and enabling the main survey lines at the boundaries of the monitoring regions to be parallel to the extension direction of the isobath as much as possible; defining the number of measuring lines and the distance between the measuring lines in the width direction, and taking the main measuring line of the boundary in the width direction of the monitoring area as a starting point; defining an optimization objective function by taking minimization of the total length of the measuring lines as an objective; and circularly traversing the river basin to be measured from the first measuring line based on a greedy algorithm until the length of the latest measuring line exceeds the width of the river, and ending the circulation, and determining the optimal measuring line layout; and verifying the optimization result of the measuring line layout by using a simulated annealing algorithm. The multi-beam measuring line can be automatically laid in combination with landform data, and the measuring line result is verified. And meanwhile, the accuracy and high-efficiency effects of data acquisition and preprocessing are achieved.

Description

Technical Field

[0001] The present application relates to the technical field of hydrological measurement, and in particular to a water depth data measurement wiring system and method. Background Art

[0002] The multi-beam bathymetry system measures the water depth data under different survey lines by emitting multiple beams of sound waves to the bottom of the water and recording the time difference and intensity of the sound wave echoes. It has a large measurement range and high accuracy, and is suitable for large-area water terrain exploration. Survey line layout refers to planning and arranging appropriate measurement lines within a specific water area to cover the target area and ensure the integrity and accuracy of data collection. The rationality of survey line layout directly affects the coverage, data quality and operation efficiency of the measurement, and is the basis for multi-beam measurement operations. In actual detection, the underwater terrain is undulating, and the survey line interval cannot be simply designed based on the average water depth. Survey line layout is usually based on a comprehensive consideration of multiple factors such as water depth changes in the survey area, terrain characteristics, project accuracy requirements, and equipment performance.

[0003] Traditional multi-beam survey line layout methods usually require manual or semi-automatic planning of survey line positions, which results in a long time for each layout task. In particular, insufficient or redundant measurement coverage may occur in complex terrain, which cannot meet the needs of efficient measurement.

[0004] Existing intelligent survey line layout methods often fall into local optimal solutions using optimization algorithms, making it difficult for survey line plans to reach global optimality in complex terrain, which is not conducive to ensuring comprehensive coverage and accuracy of measurements.

[0005] At the same time, there is no method to verify the results of the survey line layout, and manual data re-survey is still required. After collecting multi-beam water depth acoustic wave data, the pre-processing process involves multiple steps such as data calibration, error correction, and filtering. The processing process is complicated and time-consuming, affecting the overall operation efficiency.

[0006] Therefore, there is an increasing demand in the current field for a method that can automatically lay out multi-beam survey lines in combination with topographic data and verify the accuracy of the survey results, as well as an efficient data acquisition preprocessing method, which is of great significance for marine resource development, channel surveys, underwater geological surveys, seabed structure monitoring, and marine environmental protection. Summary of the invention

[0007] The purpose of this application is to provide a multi-beam survey line layout and data acquisition preprocessing method and system, which can automatically layout multi-beam survey lines in combination with topographic data and verify the survey line results, while achieving accuracy and high efficiency of data acquisition preprocessing.

[0008] The embodiment of the present application is implemented as follows: A multi-beam survey line layout and data acquisition preprocessing method, characterized by comprising the following steps: S1: Use the multi-beam survey line layout direction parallel to the isobaths to divide the river basin to be measured into several rectangular monitoring areas formed by the main survey lines, so that the main survey line at the boundary of the monitoring area is as parallel as possible to the extension direction of the isobaths; S2: Use a single-objective optimization model to determine the best survey line position: including defining the number of survey lines and the spacing between survey lines in the width direction, taking the main survey line at the width boundary of the monitoring area as the starting point; defining the optimization objective function with the goal of minimizing the total length of the survey line, which is determined by the product of the number of survey lines and the length of a single side line; setting constraints including: the overlap rate range of the monitoring area of ​​different survey lines, and satisfying the constraints of the scanning strip width, overlap rate and coverage width at the same time; S3: Based on the greedy algorithm, the optimal layout of the survey line is determined by traversing the river basin to be measured from the first survey line until the length of the latest survey line exceeds the width of the river. S4: Use simulated annealing algorithm to verify the optimization result of survey line layout, and determine that the survey line model of step S3 is valid if the error with step S3 is within a set smaller range. If it exceeds the set smaller range, re-execute steps S2-S4 until the conditions are met.

[0009] The above technical solution also includes S5: completing the survey line layout of the river basin to be measured according to the optimal survey line layout of S3 that meets the range after verification in step S4, collecting data through the multi-beam bathymetric system, and importing the collected data into the Hypack software for noise reduction and filtering to generate a smooth underwater terrain point cloud map.

[0010] In the above technical solution, in step S2, the overlap rate is calculated so that each part of the river channel is fully covered, while reducing unnecessary measurements, thereby improving measurement efficiency.

[0011] In the above technical solution, in step S2, it is determined that the overlap rate of monitoring areas of different survey lines is in the range of 10%-20%.

[0012] In the above technical solution, in step S2, the width and overlap rate of each scanning strip are calculated so that the total width of the scanning strip minus the width of the overlapping part is at least equal to the ratio of the optimized survey line length of each scanning strip to the slope cosine value.

[0013] In the above technical solution, in step S2, first calculate the total coverage width to the west of the scanning center of the i-th survey line, and then calculate the total coverage width to the east of the scanning center of the i+1-th survey line; then, subtract the west coverage width of the i-th survey line from the east coverage width of the i+1-th survey line to obtain the width of the overlapping part between the two survey lines; finally, divide the width of the overlapping part by the scanning strip width of the i-th survey line to obtain the overlap rate η.

[0014] In the above technical solution, the single-objective optimization model obtained in step S2 is as follows: st ; in is the scanning strip width of the i-th survey line, is the overlap ratio between the scanned strip of the i-th survey line and the previous strip; Indicates the optimized survey line length; is the position along the river slope; α is the slope; Indicates the coverage width west of the scanning center of the i-th scanning strip; represents the coverage width east of the scanning center of the i-th scanning strip; is the total coverage width; represents the opening angle of the multi-beam transducer; d is the depth of the river channel.

[0015] In the above technical solution, step S3 includes the following steps: S31: If the river runs north-south, the first survey line is determined by taking the eastern boundary of the rectangle that divides the river basin into its starting point and covering a width that just reaches the eastern boundary; S32: Starting from the position of the first survey line, traverse backwards in the width direction step by step with a certain length, determine the position of the next survey line, and calculate the overlap rate of the coverage width of the survey line and the previous survey line; save the survey line positions that meet the overlap rate range of 10%-20%; use the greedy algorithm to select the survey line with an overlap rate of 10%; determine the optimal position of the second survey line based on the survey line with an overlap rate of 10%, and traverse in this way; S33: Traverse in sequence until the length of the latest survey line exceeds the width of the river, then end the loop and save all the determined survey line positions before the survey line.

[0016] In the above technical solution, step S4 includes the following steps to verify the optimization result of the survey line layout: S41: Initialize algorithm parameters, set annealing initial temperature, temperature drop coefficient, end temperature, and annealing times; S42: The average overlap rate of all current survey line coordinates For the current solution, the coordinates of each survey line within the set range are Generate random disturbances and generate new survey line coordinates and the new overlap ratio , as the new average overlap rate; Determine the new overlap ratio Whether the overlap rate range is met, that is, ; If satisfied, accept the new solution; if not satisfied, confirm to accept the new solution The probability p of , the calculation formula of probability p is as follows: P= ; S43: Determine whether the new temperature reaches the end temperature. If so, output it as the optimal solution. If not, continue iteration, cool down the current temperature and reset the number of iterations. The new temperature is the product of the initial temperature and the temperature drop coefficient. S44: Compare the optimal solution obtained by the simulated annealing algorithm with the solution obtained by the greedy algorithm, and calculate the error between the two; if the error between the two is within the allowable set range, it proves that the model obtained by the greedy algorithm is valid; otherwise, repeat steps S2-S4 until the optimal survey line layout is determined and verified to be valid.

[0017] A multi-beam survey line layout and data acquisition preprocessing system is characterized in that a computer-readable storage program is stored therein, and when the program is executed, the steps of the above method are implemented.

[0018] Compared with the prior art, the present invention has at least one of the following beneficial effects: The present invention innovatively designs a multi-beam survey line and data acquisition preprocessing method by integrating the single-objective optimization model, greedy algorithm, simulated annealing algorithm and other technologies, which reduces the total length of the survey line and reduces data redundancy, thereby improving the measurement efficiency. By combining the simulated annealing algorithm to verify the survey line layout plan, the risk of falling into the local optimal solution in the optimization process is avoided, the rationality and global coverage of the survey line layout are ensured, and the survey line planning effect in complex terrain is effectively improved; It reduces the situations where the overlap rate is too high or the area is missed, ensures the reasonable overlap between the survey lines in the measurement area, and improves the comprehensiveness of the detection.

[0019] The layout of survey lines and inspection lines strictly complies with the relevant provisions of the "Technical Regulations for Underwater Topography Survey in Inland Waters", meets the technical requirements in terms of precision control, and makes the measurement results more reliable and referenceable. BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A schematic diagram of the arrangement direction of a multi-beam main survey line provided by an embodiment of the present invention.

[0021] Figure 2 A schematic diagram of a multi-beam rectangular river survey line design provided in an embodiment of the present invention.

[0022] Figure 3 A schematic diagram of a process for performing optimal survey line layout using a greedy algorithm provided in an embodiment of the present invention.

[0023] Figure 4 A schematic diagram of a process for performing optimal survey line layout using a simulated annealing algorithm provided in an embodiment of the present invention.

[0024] Figure 5 A technical roadmap for data collection and preprocessing provided for an embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0027] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0028] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the application is usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0029] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0030] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0031] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0032] The features and performance of the present application are further described in detail below in conjunction with the embodiments.

[0033] Example 1 The multi-beam survey line layout and data acquisition preprocessing method implemented according to the present invention comprises the following steps: S1: Figure 1As shown in the figure, the multi-beam survey line is laid out in the direction of the isobaths, and the river basin to be measured is divided into several rectangular partial monitoring areas formed by the main survey line. The main survey line at the boundary of the monitoring area is made as close to the isobaths as possible ( Figure 1 parallel to the direction of extension of the mid-curve).

[0034] In accordance with the relevant provisions of the Technical Specifications for Underwater Topography Survey in Inland Waters (Standard No.: CH / T 7003-2021) on multi-beam survey lines, this embodiment adopts the direction of multi-beam survey lines arranged parallel to the isobaths.

[0035] S2: Use a single-objective optimization model to determine the best survey line position; S21: Define the number of survey lines n and the survey line spacing, and take the main survey line at the boundary of the monitoring area as the starting point.

[0036] S22: Define the optimization objective function to minimize the total length of the survey line. The total length of the survey line is determined by the number of survey lines. The calculation formula for the total length of the survey line is as follows: ; Wherein, L is the total length of the survey line; n is the number of survey lines; is the measuring line length.

[0037] The optimization objective can be expressed as: ; S23: Determine the constraints for the overlap ratio to be between 10% and 20%: S24: The single objective optimization model is obtained as follows: st ; in is the scanning strip width of the i-th survey line, is the overlap ratio between the scanned strip of the i-th survey line and the previous strip; Indicates the optimized survey line length; is the position along the river slope; α is the slope; Indicates the coverage width west of the scanning center of the i-th scanning strip; represents the coverage width east of the scanning center of the i-th scanning strip; is the total coverage width; represents the opening angle of the multi-beam transducer; d is the depth of the river channel.

[0038] S3: Determine the optimal survey line layout based on the greedy algorithm loop traversal; S31: The number of survey lines n and the distance between adjacent survey lines are the key factors affecting the layout of survey lines. The distance between survey lines can be converted into the positions of different survey lines. Indicates the distance between the survey line and the river channel to the east. If the river runs north-south, the first survey line is located with the eastern boundary of the rectangular river basin partition as the starting edge and the coverage width just reaching the eastern boundary; S32: Starting from the position of the first survey line, gradually move backwards with a certain length as the step length (in the direction of river width, such as Figure 2 The next survey line is traversed (as shown in the figure), and the position of the next survey line is determined. The coverage width of the survey line and the overlap rate of the previous survey line are calculated. The positions of the survey lines with an overlap rate of 10%-20% are saved. The survey lines with an overlap rate of 10% are selected first using the greedy algorithm, because the overlap rate of 10% not only meets the requirements of the technical regulations but also has the highest work efficiency. The optimal position of the second survey line is determined based on the survey line with an overlap rate of 10%, and the survey lines are traversed in this way.

[0039] S33: Traverse in sequence until the length of the latest survey line exceeds the width of the river, which means that the survey line has exceeded the area range, and the loop ends. All the determined survey line positions before the survey line are saved.

[0040] S4: Use simulated annealing algorithm to verify the optimization results of survey line layout: S41: Initialize algorithm parameters and set the initial annealing temperature to , temperature drop coefficient (cooling rate) , end temperature , annealing times (number of iterations at each temperature) .

[0041] S42: Randomly perturb the position of the measurement line, generate a new solution, calculate the optimization objective function, and ensure that it does not fall into the local optimal solution. Repeat the process to determine whether the current number of iterations reaches the annealing number (i.e., the number of iterations at each temperature); The current solution is , which represents the average overlap rate of all current survey line coordinates, and for each survey line coordinate within a reasonable range Generate random disturbances and generate new survey line coordinates and the new overlap ratio , as the new average overlap rate; judge Whether the constraints of the target optimization equation are met, that is, If it is satisfied, the new solution is accepted; if it is not satisfied, the new solution is determined to be accepted according to the Metropolis criterion. The probability p of , the calculation formula of probability p is as follows: P=

[0042] S43: Determine the temperature Whether the end temperature is reached, if it is reached, the optimal solution is output, if not, the iteration continues, and the current temperature is cooled and the number of iterations is reset. The new temperature is .

[0043] S44: Based on the solution obtained by the simulated annealing algorithm above, we compare it with the solution obtained by the greedy algorithm and calculate the error between the two. The error between the two is very small and is within the allowable range (i.e., within 1% of the target line length), proving that the model obtained by the greedy algorithm has certain reliability and accuracy.

[0044] S5: After completing the survey line model, data is collected through the multi-beam bathymetric system, and the collected data is imported into the Hypack software for noise reduction and filtering to generate a smooth underwater terrain point cloud map.

[0045] Furthermore, the typical multi-beam bathymetric system model and parameters used in step S5 are shown in Table 1 below: Table 1 Multibeam bathymetric system models and parameters

[0046] Of course, those skilled in the art may also use other conventional multi-beam bathymetric systems according to the requirements of the test area.

[0047] Example 2 A multi-beam survey line layout and data acquisition preprocessing system is characterized in that a computer-readable storage program is stored therein, and when the program is executed, the steps of the above method are implemented.

[0048] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

Claims

1. A multi-beam survey line layout and data acquisition preprocessing method, characterized in that The following steps are involved: S1: Use the multi-beam survey line layout direction parallel to the isobaths to divide the river basin to be measured into several rectangular monitoring areas formed by the main survey lines, so that the main survey line at the boundary of the monitoring area is as parallel as possible to the extension direction of the isobaths; S2: Use a single-objective optimization model to determine the best survey line position: including defining the number of survey lines and the survey line spacing in the width direction, and taking the main survey line of the width boundary of the monitoring area as the starting point; The optimization objective function is defined with the goal of minimizing the total length of the survey line. The total length of the survey line is determined by the product of the number of survey lines and the length of a single lateral line. Setting constraints includes: the overlap rate range of monitoring areas of different survey lines, and simultaneously satisfying the scanning strip width, overlap rate and coverage width constraints; S3: Based on the greedy algorithm, the optimal survey line layout is determined by traversing the river basin to be measured from the first survey line until the length of the latest survey line exceeds the width of the river: S4: Use simulated annealing algorithm to verify the optimization result of survey line layout, and determine that the survey line model of step S3 is valid if the error with step S3 is within a set smaller range. If it exceeds the set smaller range, re-execute steps S2-S4 until the conditions are met.

2. The multi-beam survey line layout and data acquisition preprocessing method according to claim 1 is characterized in that It also includes S5: completing the survey line layout of the river basin to be measured according to the optimal survey line layout of S3 that meets the range after verification in step S4, collecting data through the multi-beam bathymetric system, and importing the collected data into the Hypack software for noise reduction and filtering to generate a smooth underwater terrain point cloud map.

3. The multi-beam survey line layout and data acquisition preprocessing method according to claim 1 is characterized in that In step S2, it is determined that the overlap rate of monitoring areas of different survey lines is in the range of 10%-20%.

4. The multi-beam survey line layout and data acquisition preprocessing method according to claim 1 is characterized in that In step S2, the width and overlap rate of each scanning strip are constrained as follows: the width and overlap rate of each scanning strip are calculated so that the total width of the scanning strip minus the width of the overlapping part is at least equal to the ratio of the optimized survey line length of each scanning strip to the slope cosine value.

5. The multi-beam survey line layout and data acquisition preprocessing method according to claim 1 is characterized in that In step S2, the coverage width constraint of each scanning strip is as follows: first calculate the total coverage width to the west of the scanning center of the i-th survey line, and then calculate the total coverage width to the east of the scanning center of the i+1-th survey line; then, subtract the west coverage width of the i-th survey line from the east coverage width of the i+1-th survey line to obtain the width of the overlapping part between the two survey lines; finally, divide the width of this overlapping part by the scanning strip width of the i-th survey line to obtain the overlap rate η.

6. The multi-beam survey line layout and data acquisition preprocessing method according to claim 1, characterized in that The single-objective optimization model obtained in step S2 is as follows: s.t. ; in is the scanning strip width of the i-th survey line, is the overlap ratio between the scanned strip of the i-th survey line and the previous strip; Indicates the optimized survey line length; is the position along the river slope; α is the slope; Indicates the coverage width west of the scanning center of the i-th scanning strip; represents the coverage width east of the scanning center of the i-th scanning strip; is the total coverage width; represents the opening angle of the multi-beam transducer; d is the depth of the river channel.

7. The multi-beam survey line layout and data acquisition preprocessing method according to claim 1 is characterized in that Step S3 includes the following steps: S31: If the river runs north-south, the first survey line is determined by taking the eastern boundary of the rectangle that divides the river basin into its starting point and covering a width that just reaches the eastern boundary; S32: Starting from the position of the first survey line, traverse backwards in the width direction step by step with a certain length, determine the position of the next survey line, and calculate the overlap rate of the coverage width of the survey line and the previous survey line; save the survey line positions that meet the overlap rate range of 10%-20%; use the greedy algorithm to select the survey line with an overlap rate of 10%; determine the optimal position of the second survey line based on the survey line with an overlap rate of 10%, and traverse in this way; S33: Traverse in sequence until the length of the latest survey line exceeds the width of the river, then end the loop and save all the determined survey line positions before the survey line.

8. The multi-beam survey line layout and data acquisition preprocessing method according to claim 1, characterized in that Step S4 includes the following steps: S41: Initialize algorithm parameters, set annealing initial temperature, temperature drop coefficient, end temperature, and annealing times; S42: The average overlap rate of all current survey line coordinates For the current solution, the coordinates of each survey line within the set range are Generate random disturbances and generate new survey line coordinates and the new overlap ratio , as the new average overlap rate; Determine the new overlap ratio Whether the overlap rate range is met, that is, ; If satisfied, accept the new solution; if not satisfied, confirm to accept the new solution The probability p of , the calculation formula of probability p is as follows: P= ； S43: Determine whether the new temperature reaches the end temperature. If so, output it as the optimal solution. If not, continue iteration, cool down the current temperature and reset the number of iterations. The new temperature is the product of the initial temperature and the temperature drop coefficient. S44: Compare the optimal solution obtained by the simulated annealing algorithm with the solution obtained by the greedy algorithm, and calculate the error between the two; if the error between the two is within the allowable set range, it proves that the model obtained by the greedy algorithm is valid; otherwise, repeat steps S2-S4 until the optimal survey line layout is determined and verified to be valid.

9. A multi-beam survey line layout and data acquisition preprocessing system, characterized in that A computer-readable storage program is stored therein, and when the program is executed, it is used to implement the steps of the multi-beam survey line layout and data acquisition preprocessing method described in any one of claims 1 to 8.

Images