Correction method and correction system for low quantization precision seabed topography data
The method corrects low-quantization-precision seabed topography data by selecting interpolation nodes and performing cubic spline interpolation, improving the accuracy of wave field modeling by addressing sharp-angle errors.
Patent Information
- Application Number
- CN202410156182.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-04
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2044-02-04
AI Technical Summary
Existing methods for obtaining and modeling seabed topography data suffer from low quantization precision, leading to inaccurate wave field forward modeling due to sharp-angle topographic structures and errors in spatial modeling.
A method and system for correcting low-quantization-precision seabed topography data by selecting interpolation nodes at midpoints of edges and convex/concave parts, performing cubic spline interpolation, and smoothing results to maintain data continuity and accuracy.
The method effectively removes sharp-angle features, enhancing the credibility of wave field forward modeling results by aligning them with actual seabed topography.
Smart Images
Figure CN118094990B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of hydroacoustic engineering, and in particular relates to a correction method and a correction system for low-quantization-precision seabed topography data. Background Art
[0002] Satellite altimetry and gravity seafloor topography inversion have always been the main means of obtaining large-scale seafloor topography data. The above technologies can be used to obtain seafloor topography data in almost all ocean areas around the world, and topographic databases such as ETOPO1 and GEBCO have been born. However, due to its technical characteristics, the accuracy of topographic data obtained using the above technologies is highly limited, generally 5% to 10% of the sea depth. In addition to the above remote sensing methods, the traditional means of sea depth measurement in the field of hydroacoustics is to deploy depth gauges, which have relatively accurate sea depth measurement results but extremely sparse measurement points and poor continuity of topographic data. At the same time, the continuous development of new acoustic seafloor topography exploration has gradually improved the measurement accuracy, such as multi-beam seafloor imaging technology, which can achieve sub-meter accuracy. However, both depth gauges and multi-beam seafloor imaging equipment need to be carried by ships to obtain seafloor topography data in some areas of the track, and large-scale data collection cannot be achieved. Therefore, as an important means of pre-sea trial demonstration, the main source of spatial modeling data in numerical simulation is still open source databases, which mainly have the problem of insufficient quantitative accuracy.
[0003] At present, mainstream finite element wavefield forward modeling methods such as finite element method and spectral element method all use point-to-point connection of terrain data. At the same time, considering the characteristics of quantization, that is, the values at both ends of a quantization interval are close to the middle, which will cause low quantization accuracy terrain data to have step-like jumps or drops. The sharp corners generated at the steps will seriously affect the credibility of the wavefield forward modeling results. Summary of the invention
[0004] The present invention provides a method for correcting low-quantization-precision seabed topographic data, which alleviates the problem of erroneous introduction of sharp-angle topographic structures and forward modeling wave field errors caused by direct use of low-quantization-precision topographic data for wave field forward modeling.
[0005] The invention provides a correction system for low-quantization-precision seabed topographic data, which is used to achieve the purpose of the correction method.
[0006] The present invention is achieved through the following technical solutions:
[0007] A method for correcting low-quantization-precision seafloor topography data, the correction method comprising the following steps:
[0008] Step 1: Select the midpoints of all rising and falling edges in the terrain data and keep them as interpolation nodes;
[0009] Step 2: Process all local parts that conform to the convex or concave terrain and retain them as interpolation nodes;
[0010] Step 3: Connect the point finally determined in step 2 with the midpoint of the rising edge or the falling edge to obtain the intersection with the horizontal part of the side close to the rising edge or the falling edge, and keep it as the interpolation node;
[0011] Step 4: After the convex or concave terrain processing is completed, start to traverse the terrain data line by line segment, and supplement the remaining horizontal segments where the interpolation nodes have not been determined; the remaining terrain should all meet the conditions of continuous rising edges or continuous falling edges; by connecting the midpoints of two rising edges or falling edges, the intersection with the horizontal part between the two edges is obtained, and it is determined as the interpolation node;
[0012] Step 5: Based on the interpolation nodes of steps 1-4, perform cubic spline interpolation;
[0013] Step 6: Smooth the result of step 5 and use the result as data for spatial modeling.
[0014] Furthermore, in step 2-4, the horizontal line segment for which the interpolation node is determined in the previous step is used as the first line segment for the next local terrain judgment; the horizontal segment that has been used as the bottom of the concave terrain and the top of the convex terrain will no longer have an interpolation node added.
[0015] Furthermore, in step 6, the result of step 5 is smoothed. Specifically, when the cubic spline interpolation results in a value that obviously exceeds the value interval corresponding to the quantization value at the location, which is manifested as a peak or valley position, these abnormal values are corrected to the maximum or minimum value of the quantization interval according to the principle of proximity, that is, the terrain "sharp corner" is excessive.
[0016] Furthermore, the step 1 is specifically as follows: if the coordinates of the two endpoints of the edge are (x1, y1) and (x2, y2) respectively, then is the interpolation node.
[0017] Furthermore, the step 2 is specifically as follows: if the coordinates of the left and right end points of the convex or concave part are (x1, y) and (x2, y) respectively, and the convex height or concave depth is h, take is the interpolation node.
[0018] A correction system for low quantitative precision seabed topography data, the correction system comprising:
[0019] The interpolation node selection module selects the midpoints of all rising and falling edges in the terrain data and retains them as interpolation nodes;
[0020] Process all parts that conform to the convex or concave terrain, among which the midpoint of the convex or concave part in the horizontal direction and the position close to 1 / 4 of the convex height or concave depth in the vertical direction are selected and retained as interpolation nodes;
[0021] Connect the last determined point with the midpoint of the rising edge or the falling edge to obtain the intersection with the horizontal part of the side close to the rising edge or the falling edge, and keep it as the interpolation node;
[0022] The interpolation node screening module starts to traverse the terrain data segment by segment after the convex or concave terrain processing is completed, and supplements the remaining horizontal segments for which the interpolation nodes have not been determined; the remaining terrain should all meet the conditions of continuous rising edges or continuous falling edges; by connecting the midpoints of two rising edges or falling edges, the intersection with the horizontal part between the two edges is obtained, and it is determined as an interpolation node;
[0023] The data processing module for spatial modeling performs cubic spline interpolation based on all the interpolation nodes retained;
[0024] The cubic spline interpolation result is smoothed and used as the data for spatial modeling.
[0025] Furthermore, the interpolation node selection module selects the midpoints of all rising and falling edges in the terrain data and retains them as interpolation nodes. Specifically, if the coordinates of the two end points of the edge are (x1, y1) and (x2, y2) respectively, then is the interpolation node.
[0026] Furthermore, the interpolation node selection module processes all the local parts that meet the convex or concave terrain. Specifically, if the coordinates of the left and right end points of the convex or concave part are (x1, y) and (x2, y), the convex height or concave depth is h, then is the interpolation node.
[0027] A computer device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the above method is implemented.
[0028] A computer-readable storage medium stores a computer program, and the computer program implements the above method when executed by a processor.
[0029] The beneficial effects of the present invention are:
[0030] Compared with the linear interpolation spatial modeling method, the present invention can effectively remove the sharp-angle terrain features that are not in line with the actual situation and are introduced by the insufficient quantization accuracy of terrain data. The results of the forward modeling of the ocean hydroacoustic wave field are more consistent with the actual situation. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Figure 1 It is a flow chart of the method of the present invention.
[0032] Figure 2 It is a schematic diagram of the processing flow of the raised or sunken terrain of the present invention.
[0033] Figure 3 It is a schematic diagram of the processing flow of the continuous step of the present invention.
[0034] Figure 4 It is a schematic diagram of the original terrain and low quantization precision terrain according to an embodiment of the present invention.
[0035] Figure 5 It is a schematic diagram of the process of processing the low quantization precision terrain according to an embodiment of the present invention and comparing it with the original terrain.
[0036] Figure 6 It is a comparative schematic diagram of propagation loss curves corresponding to the original terrain, the low quantization precision terrain and the terrain processed by the present invention according to an embodiment of the present invention. DETAILED DESCRIPTION
[0037] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.
[0038] It should be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.
[0039] It should also be understood that the terms used in this application specification are only for the purpose of describing specific embodiments and are not intended to limit the application. As used in this application specification and the appended claims, the singular forms "a", "an" and "the" are intended to include plural forms unless the context clearly indicates otherwise.
[0040] The following is attached to this application specification Figure 1-6 , the technical solutions in the embodiments of the present application are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. 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.
[0041] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.
[0042] Embodiment 1
[0043] This embodiment provides a method for correcting low-quantization-precision seabed topography data, mainly for low-quantization-precision seabed topography composed of horizontal line segments and obvious rising edges and falling edges due to insufficient quantization accuracy. The correction method includes the following steps:
[0044] Step 1: First select the midpoints of all rising and falling edges in the terrain data and keep them as interpolation nodes, as shown in the attached figure. Figure 2 and attached Figure 3 The red dot in the middle. This is because any rising and falling terrain in the quantization process is shown as a rising edge or a falling edge. The midpoint of the edge is also the separation of the upper and lower quantization intervals, and it intersects with the actual data. If the coordinates of the two endpoints of the edge are (x1, y1) and (x2, y2) respectively, then take is the interpolation node;
[0045] Step 2: Then process all Figure 2 For the convex or concave terrain shown: select the midpoint of the convex (or concave) part in the horizontal direction and the position close to the flat top (or flat bottom) 1 / 4 of the convex height (or concave depth) in the vertical direction, and retain them as interpolation nodes, such as the green dots in the figure. This is because the greater the depth of the concave and the height of the convex terrain, the greater the impact on the wave field calculation. In other words, if the actual convexity is higher but corrected to a lower convexity, the impact is weaker than if the actual convexity is lower but corrected to a higher convexity. Therefore, select the internal points of the concave or convex terrain and determine them as interpolation nodes. If the coordinates of the left and right end points of the convex or concave part are (x1, y) and (x2, y) respectively, and the convex height or concave depth is h, take (If the sea level of the coordinate axis is 0, downward is the positive direction, the concave terrain takes the "-" sign, and the convex terrain takes the "+" sign) is the interpolation node;
[0046] Step 3: Connect the point (i.e. green point) with the midpoint of the rising edge (or falling edge) (i.e. red point) to obtain the intersection with the horizontal part on the side close to the rising edge (or falling edge), and keep it as the interpolation node, such as the blue dot in the figure. This operation can fully reflect the width of the convex or concave terrain in the process of smoothing the data;
[0047] Step 4: After the convex or concave terrain processing is completed, start traversing the terrain data line by line segment, and fill in the remaining horizontal segments where the interpolation nodes are not determined. The remaining terrain should meet the requirements as shown in the attached figure. Figure 3 In the case of continuous rising edges or continuous falling edges shown in the figure, by connecting the midpoints of the two rising edges (or falling edges), the intersection with the horizontal part between the two edges is obtained, and it is determined as the interpolation node, such as the blue point in the figure. Figure 3 In the schematic diagram shown, the horizontal segment exists between the rising edge or the falling edge, which means that there must be a rise or fall in the terrain, that is, the real terrain and the quantized horizontal segment must have an intersection. The purpose of this operation is to add interpolation nodes without more prior knowledge, constrain the behavior of subsequent terrain interpolation, and ensure that the interpolation result is more natural and smooth;
[0048] Step 5: Based on the interpolation nodes of steps 1-4, perform cubic spline interpolation;
[0049] Step 6: Smooth the result of step 5 and use the result as data for spatial modeling.
[0050] A method for correcting low-quantization-precision seabed topographic data, in which in step 2-4, the horizontal line segment for which the interpolation node is determined in the previous step is used as the first line segment for the next local terrain judgment; no interpolation nodes are added to the horizontal segment that has been used as the bottom of the concave terrain and the top of the convex terrain.
[0051] A method for correcting low-quantization-precision seabed topography data, wherein the result of step 5 is smoothed in step 6. Specifically, when the cubic spline interpolation has a value that obviously exceeds the value interval corresponding to the quantization value at the location, which is manifested in the peak or valley position, for these abnormal values, they are corrected to the maximum or minimum value of the quantization interval according to the principle of proximity, that is, the terrain "sharp corner" is excessive.
[0052] From the above, we can see that Figure 4 To Attachment Figure 6 The original topographic data is attached. Figure 4 The solid black line (and the Figure 5 The low quantization accuracy data of 50m quantization interval is shown in the attached figure. Figure 4 The red dashed line (and the Figure 5 Indicated by the red dashed line in the middle.
[0053] The terrain processing flow designed by the present invention is adopted, and the interpolation nodes obtained are as shown in the attached figure. Figure 5 The solid point in the middle is shown, and the terrain preprocessing result is shown as the blue dotted line in the figure. Compared with the original terrain, the overall trend is basically reflected, but there are some differences in the depth of depression and the height of bulge. Based on this data, a spatial model is established, and the spectral element method is used for numerical simulation. The seawater density is 1020kg / m 3, speed of sound 1500m / s; seabed density 1910kg / m 3 , P wave speed 1930m / s, S wave speed 470m / s, the sound source is set to a sound pressure excitation source with a center frequency of 20Hz at 200m in the horizontal direction and 1m above the seabed. The sound pressure propagation loss of the received sound pressure signal 1m above the sea surface is shown in the attached figure. Figure 6 The blue dotted line shows the Figure 6 The black solid line in the middle is the propagation loss curve of the wave field numerical simulation using the original terrain data, and the red dotted line is the propagation loss result of the numerical simulation using low quantitative accuracy terrain modeling.
[0054] The blue dotted line has a good agreement with the original result before 4 km. Compared with the red dotted line, the application of the processing flow of the present invention can significantly increase the credibility of the forward modeling results. After that, due to the accumulated error, there are differences in the peak and trough positions between the original result and the original result, but the upper envelope value is closer to the original data.
[0055] Embodiment 2
[0056] This embodiment provides a correction system for low quantization precision seabed topography data based on the first embodiment. The correction system includes an interpolation node selection module, an interpolation node screening module and a data processing module for spatial modeling.
[0057] The interpolation node selection module first selects the midpoints of all rising and falling edges in the terrain data and retains them as interpolation nodes, as shown in the attached figure. Figure 2 and attached Figure 3 The red dot in the middle. This is because any rising and falling terrain in the quantization process is shown as a rising edge or a falling edge. The midpoint of the edge is also the separation of the upper and lower quantization intervals, and it intersects with the actual data. If the coordinates of the two endpoints of the edge are (x1, y1) and (x2, y2) respectively, then take is the interpolation node;
[0058] Then process all Figure 2 For the convex or concave terrain shown: select the midpoint of the convex (or concave) part in the horizontal direction and the position close to the flat top (or flat bottom) 1 / 4 of the convex height (or concave depth) in the vertical direction, and retain them as interpolation nodes, such as the green dots in the figure. This is because the greater the depth of the concave and the height of the convex terrain, the greater the impact on the wave field calculation. In other words, if the actual convexity is higher but corrected to a lower convexity, the impact is weaker than if the actual convexity is lower but corrected to a higher convexity. Therefore, select the internal points of the concave or convex terrain and determine them as interpolation nodes. If the coordinates of the left and right end points of the convex or concave part are (x1, y) and (x2, y) respectively, and the convex height or concave depth is h, take (If the sea level of the coordinate axis is 0, downward is the positive direction, the concave terrain takes the "-" sign, and the convex terrain takes the "+" sign) is the interpolation node;
[0059] Connect this point (i.e. green point) with the midpoint of the rising edge (or falling edge) (i.e. red point) to obtain the intersection with the horizontal part on the side close to the rising edge (or falling edge), which is retained as the interpolation node, such as the blue dot in the figure. This operation can fully reflect the width of the convex or concave terrain in the process of smoothing the data;
[0060] After the processing of the convex or concave terrain is completed, the interpolation node screening module begins to step through the terrain data line by line segment, and supplements the remaining horizontal segments where the interpolation nodes are not determined. The remaining terrain should meet the requirements as shown in the attached Figure 3 In the case of continuous rising edges or continuous falling edges shown in the figure, by connecting the midpoints of the two rising edges (or falling edges), the intersection with the horizontal part between the two edges is obtained, and it is determined as the interpolation node, such as the blue point in the figure. Figure 3 In the schematic diagram shown, the horizontal segment exists between the rising edge or the falling edge, which means that there must be a rise or fall in the terrain, that is, the real terrain and the quantized horizontal segment must have an intersection. The purpose of this operation is to add interpolation nodes without more prior knowledge, constrain the behavior of subsequent terrain interpolation, and ensure that the interpolation result is more natural and smooth;
[0061] In the interpolation node selection module and the interpolation node screening module, the horizontal line segment for which the interpolation node was determined last time is used as the first line segment for the next local terrain judgment; the horizontal segment that has been the bottom of the concave terrain and the top of the convex terrain will no longer add interpolation nodes.
[0062] The data processing module for spatial modeling performs cubic spline interpolation based on all the retained interpolation nodes;
[0063] The cubic spline interpolation result is smoothed and used as the data for spatial modeling.
[0064] The data processing module of the spatial modeling performs smoothing on the results of the cubic spline interpolation. Specifically, when the cubic spline interpolation results in a value that is significantly higher than the range of values that should be obtained by the quantization at the location, which is manifested as a peak or valley, these abnormal values are corrected to the maximum or minimum value of the quantization interval according to the principle of proximity, i.e., the terrain "sharp corner" is excessive.
[0065] As can be seen from the above, compared with the spatial modeling method that directly uses point-to-point connections, i.e., linear interpolation, the present invention can effectively remove the sharp-angle terrain features that are not in line with the actual situation and are introduced by the insufficient quantization accuracy of terrain data. The results of the forward modeling of the ocean hydroacoustic wave field are more consistent with the actual situation.
[0066] Embodiment 3
[0067] An embodiment of the present invention provides an electronic device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the memory is used to store software programs and modules, and the processor executes various functional applications and data processing by running the software programs and modules stored in the memory. The memory and the processor are connected via a bus. Specifically, the processor implements any step in the first embodiment above by running the computer program stored in the memory.
[0068] It should be understood that in the embodiments of the present invention, the processor referred to may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.
[0069] The memory may include a read-only memory, a flash memory, and a random access memory, and provides instructions and data to the processor. A part or all of the memory may also include a nonvolatile random access memory.
[0070] It should be understood that if the above-mentioned integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The above-mentioned computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the above-mentioned computer program includes computer program code, and the above-mentioned computer program code can be in source code form, object code form, executable file or some intermediate form. The above-mentioned computer-readable medium may include: any entity or device capable of carrying the above-mentioned computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the above-mentioned computer-readable storage medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction.
[0071] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.
[0072] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the above-mentioned device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of the present invention. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.
[0073] It should be noted that the methods and detailed examples provided in the above embodiments can be combined with the devices and equipment provided in the embodiments, and references can be made to each other, and no further details will be given.
[0074] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.
[0075] In the embodiments provided by the present invention, it should be understood that the disclosed apparatus / terminal equipment and method can be implemented in other ways. For example, the apparatus / equipment embodiments described above are only illustrative, for example, the division of the above modules or units is only a logical function division, and in actual implementation, other division methods can be used, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed.
[0076] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.
Claims
1. A method for correcting low-quantization-precision seafloor topography data, characterized in that: The correction method comprises the following steps: Step 1: Select the midpoints of all rising and falling edges in the terrain data and keep them as interpolation nodes; Step 2: Process all local parts that conform to the convex or concave terrain and retain them as interpolation nodes; Specifically, step 2 is as follows: if the coordinates of the left and right end points of the convex or concave part are (x1, y) and (x2, y) respectively, and the height of the convex part is h, then is the interpolation node, or the depression depth is h, take is the interpolation node; Step 3: Connect the point finally determined in step 2 with the midpoint of the rising edge or the falling edge to obtain the intersection with the horizontal part of the side close to the rising edge or the falling edge, and keep it as the interpolation node; Step 4: After the convex or concave terrain processing is completed, start to traverse the terrain data line by line segment, and supplement the remaining horizontal segments where the interpolation nodes have not been determined; the remaining terrain should all meet the conditions of continuous rising edges or continuous falling edges; by connecting the midpoints of two rising edges or falling edges, the intersection with the horizontal part between the two edges is obtained, and it is determined as the interpolation node; Step 5: Based on the interpolation nodes of steps 1-4, perform cubic spline interpolation; Step 6: Smooth the result of step 5 and use it as data for spatial modeling.
2. The method for correcting low quantization precision seabed topography data according to claim 1, characterized in that: In step 2-4, the horizontal line segment for which the interpolation node is determined in the previous step is used as the first line segment for the next local terrain judgment; no interpolation node is added to the horizontal segment that has been used as the bottom of the concave terrain and the top of the convex terrain.
3. The method for correcting low-quantization-precision seabed topography data according to claim 1, characterized in that: In step 6, the result of step 5 is smoothed. Specifically, the cubic spline interpolation may produce values that are significantly higher than the range of values that should be quantized at the location, which are reflected in the peak or valley position. For these abnormal values, they are corrected to the maximum or minimum value of the quantization interval according to the principle of proximity, that is, the terrain "sharp corner" transition.
4. A correction system for low quantization precision seabed topography data, characterized in that: The correction system uses a correction method for low quantitative precision seabed topography data as described in any one of claims 1 to 3, and the correction system includes: The interpolation node selection module selects the midpoints of all rising and falling edges in the terrain data and retains them as interpolation nodes; Process all parts that conform to the convex or concave terrain and retain them as interpolation nodes. If the coordinates of the left and right end points of the convex or concave part are (x1, y) and (x2, y) respectively, and the convex height is h, take is the interpolation node, or the depression depth is h, take is the interpolation node; Connect the last determined point with the midpoint of the rising edge or falling edge to obtain the intersection with the horizontal part of one side of the rising edge or falling edge, and keep it as the interpolation node; The interpolation node screening module starts to traverse the terrain data segment by segment after the convex or concave terrain processing is completed, and supplements the remaining horizontal segments for which the interpolation nodes have not been determined; the remaining terrain should all meet the conditions of continuous rising edges or continuous falling edges; by connecting the midpoints of two rising edges or falling edges, the intersection with the horizontal part between the two edges is obtained, and it is determined as an interpolation node; The data processing module for spatial modeling performs cubic spline interpolation based on all the interpolation nodes retained; The cubic spline interpolation result is smoothed and used as the data for spatial modeling.
5. A computer device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method according to any one of claims 1 to 3 is implemented.
6. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 3 is implemented.