A method and system for calibrating geographic coordinates of a sewage outlet into a river based on river system data

Abstract

This invention discloses a method for calibrating the geographic coordinates of sewage outfalls into rivers based on water system data, comprising the following steps: acquiring river data / electronic map data and original location data of sewage outfalls within a preset range; preprocessing the acquired river data to obtain river vector line data; wherein, the river data includes river geometric vectors and a spatial reference coordinate system, and the original location data of sewage outfalls includes the original GPS latitude and longitude information and GPS horizontal positioning accuracy information of the sewage outfalls; mapping the original location of the sewage outfalls onto the river vector line based on the original GPS latitude and longitude information of the sewage outfalls; and determining the calibration position of the sewage outfalls based on the result of mapping the original location of the sewage outfalls onto the river vector line. This method does not require additional equipment investment, and performs mapping correction by acquiring river data and combining it with the original GPS latitude and longitude information of the sewage outfalls, thus possessing high practicality and promotional value.

Description

Technical Field

[0001] This invention belongs to the field of geographic coordinate calibration technology, and in particular relates to a method and system for geographic coordinate calibration of sewage outlets into rivers based on water system data. Background Technology

[0002] River discharge outlets refer to the outlets that discharge various types of wastewater and sewage from urban, industrial, and rural areas into rivers. The geographic coordinates of these outlets are crucial foundational data for wastewater treatment, water environment monitoring, and water resource management. Currently, GPS and other satellite positioning technologies are commonly used to measure the location of these outlets. However, GPS positioning accuracy is affected by various factors, such as signal obstruction and atmospheric interference, leading to inherent errors. Furthermore, for outlets located near high-rise buildings or in forested environments, GPS positioning accuracy is even more unstable, resulting in errors and offsets in the geographic coordinates. Therefore, accurately and efficiently calibrating the geographic coordinates of river discharge outlets has become a pressing issue that needs to be addressed.

[0003] Currently, the most commonly used method for calibrating the geographic coordinates of sewage outfalls into rivers is the high-precision positioning measurement method, which can achieve high-precision geographic coordinate measurement. However, it has disadvantages such as high equipment cost and high requirements for weather conditions. It requires a lot of manpower and material resources, and is greatly affected by factors such as terrain and soil. In addition, data processing is difficult. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide a method and system for calibrating the geographic coordinates of sewage outfalls into rivers based on water system data. This method and system require no additional data acquisition equipment; they can accurately calibrate the geographic coordinates of sewage outfalls using only water system data. Furthermore, time-series data is used to correct offset points, and the potential spatial range of the sewage outfall can be estimated using the riverbank line. Compared with existing technologies, the present invention offers advantages such as low data acquisition cost, simple processing, convenient operation, and high-speed processing of massive amounts of data. It can significantly improve the accuracy and reliability of the geographic coordinate information of sewage outfalls into rivers, providing more precise basic data for wastewater treatment, water environment monitoring, and water resource management.

[0005] To achieve the above objectives, the first technical solution of the present invention is: a method for calibrating the geographic coordinates of sewage outfalls into rivers based on water system data, comprising the following steps: acquiring river data / electronic map data and original point data of sewage outfalls within a preset range; preprocessing the acquired river data / electronic map data to obtain river vector line data; wherein, the river data includes river geometric vectors and a spatial reference coordinate system, and the original point data of sewage outfalls into rivers includes the original GPS latitude and longitude information of the sewage outfalls into rivers and the GPS horizontal positioning accuracy information of the sewage outfalls into rivers; mapping the original point locations of the sewage outfalls into rivers onto the river vector lines based on the original GPS latitude and longitude information of the sewage outfalls into rivers; and determining the calibration position of the sewage outfalls into rivers based on the result of mapping the original point locations of the sewage outfalls into the river vector lines.

[0006] Preferably, preprocessing the acquired electronic map data to obtain river vector line data further includes: loading a preset electronic map into ArcGIS and performing image analysis to extract single-band images; converting the polygon data of the river data in the single-band images into river vector line data; reclassifying the data using the Spatial Analyst tool in ArcToolbox, with corresponding new values ​​of 1, 2, and 3; reclassifying the data again using the Spatial Analyst tool in ArcToolbox, setting the old value 3 to a new value of 1; creating a new line-polygon layer and line file; editing the newly created line-polygon layer for feature editing; and using the Vectorization tool on the ArcScan toolbar to set and apply vectorization to generate features and obtain river vector line data.

[0007] Preferably, mapping the original location of the sewage outlet to the river vector line based on the original GPS latitude and longitude information of the sewage outlet further includes: identifying all river vector line segments within the GPS horizontal accuracy range of the sewage outlet and determining the river vector line segment closest to the sewage outlet; wherein, a perpendicular line can be drawn between the sewage outlet and the closest river vector line segment; calculating the slope k of the closest river vector line segment: k = (y3 - y2) / (x3 - x2); calculating the intercept b of the closest river vector line segment: b = y2 - k * x2; calculating the slope k of the perpendicular line from the sewage outlet to the closest river vector line segment. ':k'=-1 / k; Calculate the intercept b':b'=y1-k'*x1 from the sewage outlet to the perpendicular line of the nearest river vector segment; Calculate the distance of the perpendicular segment from the original point of the sewage outlet to the foot of the perpendicular. If the distance of the perpendicular segment is less than the GPS horizontal accuracy, the coordinates of the sewage outlet mapped to the nearest river vector segment are: ((b'-b) / (k-k'),k*(b'-b) / (k-k')+b), where (x1, y1) are the original GPS latitude and longitude coordinates of the sewage outlet, and (x2, y2) and (x3, y3) are the coordinates of the two endpoints of the nearest river vector segment.

[0008] Preferably, mapping the original location of the sewage outlet to the river vector line based on the original GPS latitude and longitude information of the sewage outlet further includes: identifying all river vector line segments within the GPS horizontal accuracy range of the sewage outlet and determining the river vector line segment closest to the sewage outlet; wherein, a perpendicular line cannot be drawn between the sewage outlet and the closest river vector line segment; calculating the distance between the two endpoints of the sewage outlet and the closest river vector line segment according to the Pythagorean theorem; and mapping the sewage outlet to the endpoint of the closest river vector line segment with the shorter distance between the two endpoints.

[0009] Preferably, mapping the original location of the sewage outlet to the river vector line based on the original GPS latitude and longitude information of the sewage outlet further includes: acquiring the original GPS latitude and longitude information and GPS horizontal positioning accuracy information of the sewage outlet; identifying all river vector line segments within the GPS horizontal positioning accuracy range of the sewage outlet and determining the river vector line segment closest to the sewage outlet; calculating the correction range S of the sewage outlet mapped to the nearest river vector line segment: S=(P∩L)∪(P_edge∩L)∪(P∩L_edge), where P represents the GPS horizontal accuracy range of the sewage outlet, L represents the nearest river vector line segment, P_edge represents the boundary of the GPS horizontal accuracy range of the sewage outlet, and L_edge represents the boundary of the nearest river vector line segment.

[0010] Preferably, the sewage outlet has a location time series data attribute. Before mapping the original location of the sewage outlet to the river vector line based on the original GPS latitude and longitude information of the sewage outlet, the method further includes calculating the distance and time difference between each pair of adjacent time series points corresponding to the sewage outlet. If the distance and time difference between two adjacent time series points exceed a threshold, and the corresponding GPS horizontal accuracy range is greater than the threshold, offset correction is performed by interpolation: For adjacent original time series points (x1, y1) and (x2, y2), the coordinates (xi, yi) of the interpolation point are calculated according to the interpolation method, where i represents the position of the interpolation point between the original time series points: xi = x1 + (i - t1) * (x2 - x1) / (t2 - t1), yi = y1 + (i - t1) * (y2 - y1) / (t2-t1), where (xi,yi) are the coordinates of the interpolation point, t1 and t2 are the timestamps of adjacent trajectory points, and i is the timestamp of the interpolation point; the horizontal positioning accuracy of the interpolation point is calculated based on the horizontal positioning accuracy of the original time series points used for the interpolation point, and the horizontal positioning accuracy of the interpolation point is calculated using a weighted average: when the interpolation point uses k original time series points, their horizontal positioning accuracies are d1, d2, ..., dk respectively, then the horizontal positioning accuracy of the interpolation point can be calculated using a weighted average: d=(w1d1+w2d2+...+wk*dk) / (w1+w2+...+wk), where wi represents the weight of the i-th original time series point; if the horizontal positioning accuracy of the interpolation point is less than the horizontal positioning accuracy of the original point, then the coordinates and horizontal positioning accuracy of the interpolation point are used, otherwise the coordinates of the original point are used.

[0011] Preferably, preprocessing the acquired river data to obtain river vector line data further includes: the river data is water system geographic information data, obtaining the polygon data of the water system geographic information data, and converting the polygon data into river vector line data using the feature-to-line conversion tool in the ArcGIS toolbox data management tool.

[0012] Preferably, the preprocessing of the acquired river data to obtain river vector line data further includes: during the preprocessing of the acquired river data to obtain river vector line data, ensuring that the original location data of the sewage outlets into the river and the river vector line data use the same spatial reference to achieve data alignment.

[0013] Preferably, after determining the calibration location coordinates of each of the sewage outlets into the river, the method further includes: comparing the calibration location coordinates with the actual surveyed location; if they are inconsistent, performing manual calibration within the correction range S.

[0014] Based on the same concept, the second technical solution of the present invention is: a geographic coordinate calibration system for sewage outfalls into rivers based on water system data, comprising: a data acquisition module, used to acquire river data / electronic map data and original point data of sewage outfalls into rivers within a preset range, and preprocess the acquired river data / electronic map data to obtain river vector line data; wherein, the river data includes river geometric vectors and spatial reference coordinate systems, and the original point data of sewage outfalls into rivers includes the original GPS latitude and longitude information of the sewage outfalls into rivers and the GPS horizontal positioning accuracy information of the sewage outfalls into rivers; a data processing module, used to map the original point of the sewage outfall into rivers onto the river vector line based on the original GPS latitude and longitude information of the sewage outfalls into rivers; and a calibration module, used to determine the calibration position of the sewage outfall into rivers based on the result of mapping the original point of the sewage outfall into the river vector line.

[0015] Based on the same concept, the present invention also provides a computer device, comprising: a memory for storing a processing program; and a processor, wherein the processor, when executing the processing program, implements the above-described method for calibrating the geographic coordinates of sewage outlets into rivers based on water system data.

[0016] Based on the same concept, the present invention also provides a readable storage medium storing a processing program, which, when executed by a processor, implements the above-described method for calibrating the geographic coordinates of sewage outlets into rivers based on water system data.

[0017] Because the present invention adopts the above technical solution, it has the following advantages and positive effects compared with the prior art:

[0018] 1. The technical solution of this invention requires no additional equipment investment. By mapping and correcting the acquired river data in conjunction with the raw GPS latitude and longitude information of the sewage discharge outlets, the acquisition cost is reduced. The mapping process is relatively simple and less affected by natural factors such as terrain, providing more accurate and reliable data. Therefore, the technical solution of this embodiment has high practicality and promotional value, effectively improving the accuracy and reliability of the geographical coordinate information of sewage discharge outlets, and providing more scientific and precise support for water environment management and protection.

[0019] 2. The technical solution of the present invention can obtain river vector line data by acquiring electronic maps or water system geographic information data provided by the government, processing the data, and obtaining the data without the need for additional data acquisition equipment, thereby reducing operating costs.

[0020] 3. When the sewage discharge outlet into the river has location time series data attributes, the technical solution of this invention corrects the time series points corresponding to the sewage discharge outlet based on the time series, so as to correct the problem of low GPS horizontal positioning accuracy caused by environmental factors, location and other factors. This makes the corrected point more accurate. Attached Figure Description

[0021] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, wherein:

[0022] Figure 1 This is a flowchart of the geographical coordinate calibration method for sewage outlets into rivers based on water system data according to the present invention.

[0023] Figure 2 This is a flowchart illustrating a method for mapping the original location of a sewage outlet into a river onto a river vector line, according to an embodiment of the present invention.

[0024] Figure 3 This is a flowchart illustrating a method for mapping the original location of a sewage outlet into a river onto the river vector line, according to another embodiment of the present invention.

[0025] Figure 4 (a) is the corresponding invention Figure 2 Schematic diagram corresponding to the method implementation embodiment, Figure 4 (b) is the corresponding invention Figure 3 A schematic diagram corresponding to the method implementation. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer from the following description and claims. It should be noted that the drawings are all in a very simplified form and use non-precise ratios, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0027] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0028] Example 1

[0029] like Figure 1 As shown in the figure, this embodiment provides a method for calibrating the geographic coordinates of sewage outfalls into rivers based on water system data, including the following steps:

[0030] S100: Acquire river data / electronic map data and original location data of sewage outlets into the river within a preset range, and preprocess the acquired river data / electronic map data to obtain river vector line data; wherein, the river data includes river geometric vectors and spatial reference coordinate system, and the original location data of sewage outlets into the river includes the original GPS latitude and longitude information of the sewage outlets into the river and the GPS horizontal positioning accuracy information of the sewage outlets into the river.

[0031] S200: Based on the original GPS latitude and longitude information of the sewage outlet into the river, map the original location of the sewage outlet into the river vector line;

[0032] S300: Determine the calibration position of the sewage outlet based on the result of mapping the original location of the sewage outlet into the river vector line.

[0033] The technical solution of this embodiment requires no additional equipment investment. By mapping and correcting the acquired river data in conjunction with the raw GPS latitude and longitude information of the sewage discharge outlets into the river, the data acquisition cost is reduced. The mapping process is relatively simple and less affected by natural factors such as terrain, providing more accurate and reliable data. Therefore, the technical solution of this embodiment has high practicality and promotional value, effectively improving the accuracy and reliability of the geographical coordinate information of sewage discharge outlets into the river, and providing more scientific and precise support for water environment management and protection.

[0034] Preferably, preprocessing the acquired electronic map data to obtain river vector line data further includes: loading a preset electronic map into ArcGIS and performing image analysis to extract single-band images; converting the polygon data of the river data in the single-band images into river vector line data; reclassifying the data using the Spatial Analyst tool in ArcToolbox, with corresponding new values ​​of 1, 2, and 3; reclassifying the data again using the Spatial Analyst tool in ArcToolbox, setting the old value 3 to a new value of 1; creating a new line-polygon layer and line file; editing the newly created line-polygon layer for feature editing; and using the Vectorization tool on the ArcScan toolbar to set and apply vectorization to generate features and obtain river vector line data.

[0035] To obtain river vector line data, this embodiment extracts water system data from Tianditu (a Chinese online map platform) and then performs vector conversion to obtain river vector line data. No additional data acquisition equipment is required, resulting in low acquisition costs and laying the foundation for the widespread application of the method in this embodiment.

[0036] Preferably, preprocessing the acquired river data to obtain river vector line data further includes: the river data is water system geographic information data, obtaining the polygon data of the water system geographic information data, and converting the polygon data into river vector line data using the feature-to-line conversion tool in the ArcGIS toolbox data management tool.

[0037] Of course, as in this embodiment, we can also directly obtain the water system geographic information data provided by the government. The water system geographic information data includes river geometric vectors and spatial reference coordinate systems. These are expressed in the form of surface data. In this embodiment, we use ArcGIS tools to convert these surface data into line data, that is, river vector line data, so that the original locations of sewage outlets into the river can be mapped to the river vector lines in the future.

[0038] Preferably, the preprocessing of the acquired river data to obtain river vector line data further includes: during the preprocessing of the acquired river data to obtain river vector line data, ensuring that the original location data of the sewage outlets into the river and the river vector line data use the same spatial reference to achieve data alignment.

[0039] The most accurate distance measurements are obtained when the input data is projected using an equidistant coordinate system. While distance calculations can be performed in any coordinate system, results may be inaccurate or even meaningless when the data uses a geographic coordinate system or an inappropriate projected coordinate system is selected. If the river channel vector line data and the original location data of the sewage outfalls have different spatial references, dynamically changing the projection can lead to performance degradation (and cause misalignment and inaccuracies between data). For reliable performance and output accuracy, all data should have the same spatial reference.

[0040] Preferred, see Figure 2 , Figure 4 In (a), mapping the original location of the sewage outlet into the river vector line based on the original GPS latitude and longitude information of the sewage outlet further includes:

[0041] S201: Identify all river vector segments within the GPS horizontal accuracy range of the sewage discharge outlet and determine the river vector segment closest to the sewage discharge outlet; wherein, a perpendicular line can be drawn between the sewage discharge outlet and the nearest river vector segment.

[0042] S202: Calculate the slope k of the nearest river channel vector segment: k = (y3 - y2) / (x3 - x2);

[0043] S203: Calculate the intercept b of the nearest river channel vector segment: b = y² - k*x²;

[0044] S204: Calculate the slope k' of the perpendicular line from the sewage outlet into the river to the nearest river channel vector segment: k' = -1 / k;

[0045] S205: Calculate the intercept b' of the perpendicular line from the sewage outlet into the river to the nearest river channel vector segment: b' = y1 - k' * x1;

[0046] S206: Calculate the distance of the perpendicular segment from the original point of the sewage outlet to the foot of the perpendicular. If the distance of the perpendicular segment is less than the GPS horizontal accuracy, the coordinates of the sewage outlet mapped to the nearest river channel vector segment are: ((b'-b) / (k-k'), k*(b'-b) / (k-k')+b), where (x1, y1) are the original GPS latitude and longitude coordinates of the sewage outlet, and (x2, y2) and (x3, y3) are the coordinates of the two endpoints of the nearest river channel vector segment.

[0047] If there is only one river channel vector segment, the distance can be directly obtained. When there are multiple river channel vector segments, first determine the river channel vector segment that is closest to the sewage discharge outlet, and then map the sewage discharge outlet.

[0048] Preferred, see Figure 3 , Figure 4 (b) Mapping the original location of the sewage outlet into the river vector line based on the original GPS latitude and longitude information of the sewage outlet further includes:

[0049] S211: Identify all river vector segments within the GPS horizontal accuracy range of the sewage discharge outlet and determine the river vector segment closest to the sewage discharge outlet; wherein, a perpendicular line cannot be drawn between the sewage discharge outlet and the closest river vector segment;

[0050] S212: Calculate the distance between the two endpoints of the line segment connecting the sewage outlet into the river to the nearest river channel vector segment using the Pythagorean theorem;

[0051] S213: Map the sewage outlet into the river to the endpoint of the shortest distance of the connecting line segment on the nearest river channel vector line segment.

[0052] It should be noted that if the distance between the vertical line segments or the distance between the connecting line segments is less than the GPS horizontal accuracy of the sewage outlet into the river, calibration should be performed based on the calibration results; otherwise, no calibration should be performed, and the original location should continue to be used. This is because if the distance between the vertical line segments or the distance between the connecting line segments exceeds the GPS horizontal accuracy range of the sewage outlet into the river, it indicates that the original location has a significant offset and is not suitable for blind correction, requiring further analysis.

[0053] Preferably, mapping the original location of the sewage outlet to the river vector line based on the original GPS latitude and longitude information of the sewage outlet further includes: acquiring the original GPS latitude and longitude information and GPS horizontal positioning accuracy information of the sewage outlet; identifying all river vector line segments within the GPS horizontal positioning accuracy range of the sewage outlet and determining the river vector line segment closest to the sewage outlet; calculating the correction range S of the sewage outlet mapped to the nearest river vector line segment: S=(P∩L)∪(P_edge∩L)∪(P∩L_edge), where P represents the GPS horizontal accuracy range of the sewage outlet, L represents the nearest river vector line segment, P_edge represents the boundary of the GPS horizontal accuracy range of the sewage outlet, and L_edge represents the boundary of the nearest river vector line segment.

[0054] When the original GPS horizontal positioning accuracy of the sewage outlet into the river is poor, it may not be possible to make accurate corrections. In this case, it is necessary to determine a correction range S that maps the sewage outlet into the nearest river channel vector segment to assist in the on-site survey and positioning of the final sewage outlet location.

[0055] Preferably, the sewage outlet has a location time series data attribute. Before mapping the original location of the sewage outlet to the river vector line based on the original GPS latitude and longitude information of the sewage outlet, the method further includes calculating the distance and time difference between each pair of adjacent time series points corresponding to the sewage outlet. If the distance and time difference between two adjacent time series points exceed a threshold, and the corresponding GPS horizontal accuracy range is greater than the threshold, offset correction is performed by interpolation: For adjacent original time series points (x1, y1) and (x2, y2), the coordinates (xi, yi) of the interpolation point are calculated according to the interpolation method, where i represents the position of the interpolation point between the original time series points: xi = x1 + (i - t1) * (x2 - x1) / (t2 - t1), yi = y1 + (i - t1) * (y2 - y1) / (t2-t1), where (xi,yi) are the coordinates of the interpolation point, t1 and t2 are the timestamps of adjacent trajectory points, and i is the timestamp of the interpolation point; the horizontal positioning accuracy of the interpolation point is calculated based on the horizontal positioning accuracy of the original time series points used for the interpolation point, and the horizontal positioning accuracy of the interpolation point is calculated using a weighted average: when the interpolation point uses k original time series points, their horizontal positioning accuracies are d1, d2, ..., dk respectively, then the horizontal positioning accuracy of the interpolation point can be calculated using a weighted average: d=(w1d1+w2d2+...+wk*dk) / (w1+w2+...+wk), where wi represents the weight of the i-th original time series point; if the horizontal positioning accuracy of the interpolation point is less than the horizontal positioning accuracy of the original point, then the coordinates and horizontal positioning accuracy of the interpolation point are used, otherwise the coordinates of the original point are used.

[0056] GPS positioning of some sewage discharge outlets into rivers may be affected by various factors, such as building obstruction and signal interference. If the sewage discharge outlet location has positioning time series data, interpolation can be used to fill in potentially offset time series points. If the distance between two adjacent time series points is relatively large but the time difference is small, and the GPS horizontal positioning accuracy is high, then the possibility of time series point offset between them is considered high. For these potentially offset time series points, a linear interpolation algorithm is used to calculate their positions based on the distance and time difference between adjacent points. A weight adjustment dimension is also introduced, where wi represents the weight of the i-th original time series point, which can be set based on factors such as distance and timestamp. For points with poor quality (i.e., poor GPS horizontal positioning accuracy), the weight can be reduced, while points with better quality are given higher weights.

[0057] Preferably, after determining the calibration location coordinates of each of the sewage outlets into the river, the method further includes: comparing the calibration location coordinates with the actual surveyed location; if they are inconsistent, performing manual calibration within the correction range S.

[0058] Compared with existing technologies, the technical solution of this embodiment has higher accuracy and reliability. By projecting the sewage outlet into the river onto the nearest waterway shoreline, the location calibration of the sewage outlet is achieved. This method requires simpler equipment and tools than traditional methods, reducing calibration costs and effectively avoiding the problem of accurately determining the river where the sewage outlet is located, which is a problem in traditional methods. It also eliminates the need for extensive on-site manual measurement work and allows calibration to be completed in a shorter time. Furthermore, by using time-series data to correct the offset point and superimposing GPS horizontal positioning accuracy and waterway shoreline data, the accuracy and reliability of the calibration can be further improved. This provides more precise data support for environmental protection, water resource management, and other fields, and has broad application prospects.

[0059] Example 2

[0060] Based on the same concept, the second technical solution of the present invention is: a geographic coordinate calibration system for sewage outfalls into rivers based on water system data, comprising: a data acquisition module, used to acquire river data / electronic map data and original point data of sewage outfalls into rivers within a preset range, and preprocess the acquired river data / electronic map data to obtain river vector line data; wherein, the river data includes river geometric vectors and spatial reference coordinate systems, and the original point data of sewage outfalls into rivers includes the original GPS latitude and longitude information of the sewage outfalls into rivers and the GPS horizontal positioning accuracy information of the sewage outfalls into rivers; a data processing module, used to map the original point of the sewage outfall into rivers onto the river vector line based on the original GPS latitude and longitude information of the sewage outfalls into rivers; and a calibration module, used to determine the calibration position of the sewage outfall into rivers based on the result of mapping the original point of the sewage outfall into the river vector line.

[0061] The technical solution of this embodiment boasts high accuracy and reliability. By projecting the sewage outfall onto the nearest riverbank, the location of the outfall is calibrated. Compared to traditional methods, this approach requires simpler equipment and tools, reducing calibration costs. It effectively avoids the problem of accurately determining the river where the outfall is located, eliminating the need for extensive on-site manual measurements and enabling calibration to be completed in a shorter time. Furthermore, by using time-series data to correct offset points and superimposing GPS horizontal positioning accuracy and riverbank line data, the accuracy and reliability of the calibration can be further improved. This provides more precise data support for environmental protection, water resource management, and other fields, demonstrating broad application prospects.

[0062] Based on the same inventive concept, the present invention also provides a computer device, comprising: a memory for storing a processing program; and a processor, wherein the processor, when executing the processing program, implements any one of the above-described methods for calibrating the geographic coordinates of sewage outlets into rivers based on water system data.

[0063] Based on the same inventive concept, the present invention also provides a readable storage medium storing a processing program, which, when executed by a processor, implements any one of the above-described methods for calibrating the geographic coordinates of sewage outlets into rivers based on water system data.

[0064] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as mobile storage devices, read-only memory (ROM), magnetic disks, or optical disks.

[0065] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they shall still fall within the protection scope of the present invention.

Claims

1. A method for calibrating the geographic coordinates of sewage outfalls into rivers based on water system data, characterized in that, Includes the following steps: Acquire river channel data / electronic map data and original location data of sewage outfalls within a preset range. Preprocess the acquired river channel data / electronic map data to obtain river channel vector line data. The river channel data includes river channel geometric vectors and spatial reference coordinate system. The original location data of sewage outfalls includes the original GPS latitude and longitude information of the sewage outfalls and the GPS horizontal positioning accuracy information of the sewage outfalls. Based on the original GPS latitude and longitude information of the sewage outlet into the river, the original location of the sewage outlet into the river is mapped to the river vector line; The calibration position of the sewage outlet is determined based on the result of mapping the original location of the sewage outlet into the river vector line.

2. The method for calibrating the geographic coordinates of sewage outfalls into rivers based on water system data according to claim 1, characterized in that, Preprocessing the acquired electronic map data to obtain river vector line data further includes: Load the preset electronic map into ArcGIS and perform image analysis to extract single-band images; Convert the area data of river channel data in single-band images into river channel vector line data; In ArcToolbox, click the Spatial Analyst tool to reclassify the data, with the corresponding new values ​​being 1, 2, and 3 respectively. In ArcToolbox, click the Spatial Analyst tool to reclassify again, setting the old value of 3 to the new value of 1; Create a new line and polygon layer and a line file. Edit the newly created line and polygon layer to edit features. Click on the vectorization button on the ArcScan toolbar to set up and apply vectorization to generate features and obtain river vector line data.

3. The method for calibrating the geographic coordinates of sewage outfalls into rivers based on water system data according to claim 1, characterized in that, Mapping the original location of the sewage outlet into the river vector line based on the original GPS latitude and longitude information of the sewage outlet further includes: Identify all river channel vector segments within the GPS horizontal accuracy range of the sewage discharge outlet and determine the river channel vector segment closest to the sewage discharge outlet; wherein, a perpendicular line can be drawn between the sewage discharge outlet and the nearest river channel vector segment; Calculate the slope k of the nearest river channel vector segment: k = (y3 - y2) / (x3 - x2); Calculate the intercept b of the nearest river channel vector segment: b = y² - k*x²; Calculate the slope k' of the perpendicular line from the sewage outlet into the river to the nearest river channel vector segment: k' = -1 / k; Calculate the intercept b' of the perpendicular line from the sewage outlet into the river to the nearest river channel vector segment: b' = y1 - k' * x1; Calculate the distance of the perpendicular segment from the original point of the sewage outlet to the foot of the perpendicular. If the distance of the perpendicular segment is less than the GPS horizontal accuracy, the coordinates of the sewage outlet mapped to the nearest river channel vector segment are: ((b'-b) / (k-k'), k*(b'-b) / (k-k')+b), where (x1, y1) are the original GPS latitude and longitude coordinates of the sewage outlet, and (x2, y2) and (x3, y3) are the coordinates of the two endpoints of the nearest river channel vector segment.

4. The method for calibrating the geographic coordinates of sewage outfalls into rivers based on water system data according to claim 1, characterized in that, Based on the original GPS latitude and longitude information of the sewage outlet into the river, mapping the original location of the sewage outlet into the river vector line further includes: Identify all river channel vector segments within the GPS horizontal accuracy range of the sewage discharge outlet and determine the river channel vector segment closest to the sewage discharge outlet; wherein, a perpendicular line cannot be drawn between the sewage discharge outlet and the nearest river channel vector segment; Calculate the distance between the two endpoints of the line segment connecting the sewage outlet into the river to the nearest river channel vector segment using the Pythagorean theorem; Map the sewage outlet into the river to the endpoint of the shortest line segment on the nearest river channel vector segment.

5. The method for calibrating the geographic coordinates of sewage outlets into rivers based on water system data according to claim 3 or 4, characterized in that, Based on the original GPS latitude and longitude information of the sewage outlet into the river, mapping the original location of the sewage outlet into the river vector line further includes: Obtain the raw GPS latitude and longitude information and GPS horizontal positioning accuracy information of sewage discharge outlets into rivers; Identify all river vector segments within the GPS horizontal positioning accuracy range of the sewage discharge outlet and determine the river vector segment closest to the sewage discharge outlet. Calculate the correction range S mapped from the sewage discharge outlet to the nearest river channel vector segment: S=(P∩L)∪(P_edge∩L)∪(P∩L_edge), where P represents the GPS horizontal accuracy range of the sewage discharge outlet, L represents the nearest river channel vector segment, P_edge represents the boundary of the GPS horizontal accuracy range of the sewage discharge outlet, and L_edge represents the boundary of the nearest river channel vector segment.

6. The method for calibrating the geographic coordinates of sewage outfalls into rivers based on water system data according to claim 1, characterized in that, The sewage outfall has location time series data attributes. Before mapping the original location of the sewage outfall to the river vector line based on the original GPS latitude and longitude information of the sewage outfall, the method further includes calculating the distance and time difference between each pair of adjacent time series points corresponding to the sewage outfall. If the distance and time difference between two adjacent time series points exceed a threshold, and the corresponding GPS horizontal accuracy range is greater than the threshold, offset correction is performed by interpolation. For adjacent original time series points (x1, y1) and (x2, y2), the coordinates (xi, yi) of the interpolation point are calculated using the interpolation method, where i represents the position of the interpolation point between the original time series points: xi=x1+(i-t1)*(x2-x1) / (t2-t1), yi=y1+(i-t1)*(y2-y1) / (t2-t1), where (xi,yi) are the coordinates of the interpolation point, t1 and t2 are the timestamps of adjacent trajectory points, and i is the timestamp of the interpolation point; Based on the horizontal positioning accuracy of the original time series points used for interpolation, the horizontal positioning accuracy of the interpolation points is calculated, and then a weighted average is used to calculate the horizontal positioning accuracy of the interpolation points. When k original time series points are used for interpolation, and their horizontal positioning accuracies are d1, d2, ..., dk, the horizontal positioning accuracy of the interpolation points can be calculated using a weighted average: d = (w1d1 + w2d2 + ... + wk*dk) / (w1 + w2 + ... + wk), where wi represents the weight of the i-th original time series point; If the horizontal positioning accuracy of the interpolation point is less than that of the original point, then the coordinates and horizontal positioning accuracy of the interpolation point are used; otherwise, the coordinates of the original point are used.

7. The method for calibrating the geographic coordinates of sewage outfalls into rivers based on water system data according to claim 1, characterized in that, Preprocessing the acquired river channel data to obtain river channel vector line data further includes: The river data is water system geographic information data. The polygon data of the water system geographic information data is obtained, and the polygon data is converted into river vector line data by using the feature to line conversion tool in the data management toolbox of ArcGIS toolbox.

8. The method for calibrating the geographic coordinates of sewage outlets into rivers based on water system data according to claim 2 or 7, characterized in that, Preprocessing the acquired river channel data to obtain river channel vector line data further includes: In the process of preprocessing the acquired river data to obtain river vector line data, the original location data of the sewage outlets into the river and the river vector line data use the same spatial reference to achieve data alignment.

9. The method for calibrating the geographic coordinates of sewage outlets into rivers based on water system data according to claim 5, characterized in that, After determining the calibration location coordinates of each of the aforementioned sewage discharge outlets into the river, the process further includes: The calibration location coordinates are compared with the actual surveyed location. If they do not match, manual calibration is performed within the correction range S.

10. A geographic coordinate calibration system for sewage outfalls into rivers based on water system data, characterized in that, include: The data acquisition module is used to acquire river data / electronic map data and original location data of sewage outfalls within a preset range, and to preprocess the acquired river data / electronic map data to obtain river vector line data; wherein, the river data includes river geometric vectors and spatial reference coordinate system, and the original location data of sewage outfalls includes the original GPS latitude and longitude information of the sewage outfalls and the GPS horizontal positioning accuracy information of the sewage outfalls; The data processing module is used to map the original location of the sewage outlet into the river onto the river vector line based on the original GPS latitude and longitude information of the sewage outlet. The calibration module is used to determine the calibration position of the sewage outlet based on the result of mapping the original point of the sewage outlet into the river vector line.

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