Three-dimensional digital river simulation method based on remote sensing inversion calculation

Abstract

The invention relates to the technical field of river channel simulation, and discloses a three-dimensional digital river channel simulation method based on remote sensing inversion calculation, and the method comprises the steps: obtaining a river channel image through an optical remote sensing technology, judging and eliminating cloud layer shielding, extracting a river bank line, obtaining a river channel center line and a river channel width, and finally achieving the three-dimensional digital simulation of a river channel. The method comprises the specific steps of obtaining an initial remote sensing image of a target river channel, judging whether cloud layer shielding exists and removing the cloud layer shielding, extracting and recording end points and lengths of two banks of the river channel, dividing river bank segmentation points according to a proportion, connecting the two bank segmentation points to obtain midline points and fitting the midline points into a river channel midline. And then, through the midline segmentation point, planning a vertical line by using a water flow direction, obtaining the width of the river channel, and finally completing digital simulation of the river channel through a measuring scale calibration strategy. The method can effectively improve the accuracy of river simulation, and provides a scientific basis for water conservancy management, environment monitoring and the like.

Description

Technical Field

[0001] The invention relates to the technical field of river channel simulation, and in particular to a three-dimensional digital river channel simulation method based on remote sensing inversion calculation. Background Art

[0002] With the intensification of global climate change and human activities, the management and monitoring of river systems have become important tasks in the fields of environmental science and water conservancy engineering; digital modeling of river channels is an important research topic in the fields of water conservancy, hydrology and environmental monitoring; with the rapid development of remote sensing technology, the use of remote sensing data for three-dimensional digital modeling of river channels, especially the river channel simulation method based on remote sensing image inversion calculation, has become a research hotspot; however, the existing remote sensing image processing technology still has certain technical bottlenecks. When facing complex river channel morphology, the existing technology cannot accurately calculate the center line of the river channel according to the length of the two banks of the river channel. The center line of the river channel is an important basis for measuring the width of the river channel. The error in calculating the center line of the river channel will lead to the error in calculating the width of the river channel. In addition, when the existing technology calculates the width of the river channel according to the flow direction of the river on the center line of the river channel, the width of the river channel at different points often intersects, resulting in inaccurate measurement.

[0003] In summary, there is an urgent need for a three-dimensional digital river simulation method based on remote sensing inversion calculation to accurately measure the width of the river and perform accurate river simulation. Summary of the invention

[0004] The present invention provides a three-dimensional digital river simulation method based on remote sensing inversion calculation, which promotes solving the problems mentioned in the above background technology.

[0005] The present invention provides the following technical solution: a three-dimensional digital river simulation method based on remote sensing inversion calculation, specifically comprising: Obtain a river channel that needs to be digitally simulated, and record it as a target river channel; An optical remote sensing image of a target river channel is obtained by using optical remote sensing technology, and recorded as an initial remote sensing image; Determine whether the target river channel in the initial remote sensing image is blocked by clouds; If the target river channel in the initial remote sensing image is blocked by clouds, the cloud removal and shadow removal algorithm is used to remove the clouds blocking the target river channel in the initial remote sensing image; The initial remote sensing image processed by the cloud removal and shadow removal algorithm or the initial remote sensing image in which the target river channel is not blocked by clouds is recorded as the target remote sensing image; Obtain two riverbanks of a target river in a target remote sensing image, and record them as a first riverbank and a second riverbank respectively; The two endpoints of the first river bank are recorded as the first endpoint and the second endpoint; The two endpoints of the second river bank are recorded as the third endpoint and the fourth endpoint; The direction from the first end point to the second end point on the first river bank is defined as the positive direction of the first river bank; The direction from the third endpoint to the fourth endpoint on the second river bank is defined as the positive direction of the second river bank; Get the length of the first river bank, recorded as the first length; Get the length of the second river bank, and record it as the second length; Obtain the center line of the target river channel according to the river channel center line acquisition strategy; The center line of the target river channel is recorded as the center line of the river channel; The width of the target river channel is obtained according to the river channel width acquisition strategy; Correct the data measured by the measuring ruler according to the measuring ruler calibration strategy; The river channel is digitally simulated using the corrected data.

[0006] Optionally, acquiring the center line of the target river channel according to the river channel center line acquisition strategy specifically includes: Calculate the first length ÷ the second length and record the result as the riverbank length ratio; Obtain endpoints of the second river bank, wherein the endpoint closest to the first endpoint is the third endpoint, and the endpoint closest to the second endpoint is the fourth endpoint; On the second river bank, starting from the third endpoint, select division points in sequence in the positive direction of the second river bank, with an interval of 10 meters between each division point, and record the division points in sequence along the positive direction of the second river bank as the first division point of the second river bank, the second division point of the second river bank...the Ath division point of the second river bank, where A refers to the number of division points on the second river bank; On the first river bank, starting from the first end point, division points are taken in sequence in the positive direction of the first river bank. The interval between each division point is 10 meters × the ratio of the river bank length, and the division points are recorded in sequence along the positive direction of the first river bank as the first division point of the first river bank, the second division point of the first river bank...the Bth division point of the first river bank, where B refers to the number of division points on the first river bank, and B=A.

[0007] Optionally, acquiring the center line of the target river channel according to the river channel center line acquisition strategy specifically includes: Connect the first dividing point of the first river bank and the first dividing point of the second river bank to form a first auxiliary line segment, obtain the midpoint of the first auxiliary line segment, and record it as the first midline point; connect the second dividing point of the first river bank and the second dividing point of the second river bank to form a second auxiliary line segment, obtain the midpoint of the second auxiliary line segment, and record it as the second midline point... Connect the Bth dividing point of the first river bank and the Ath dividing point of the second river bank to form the Cth auxiliary line segment, obtain the midpoint of the Ath auxiliary line segment, and record it as the Cth midline point, and C=B=A; Obtain the first midline point, the second midline point, ... the Cth midline point; Fit the first midline point, the second midline point, ... the Cth midline point into a smooth curve; The smooth curve is the center line of the target river channel.

[0008] Optionally, the acquiring the width of the target river channel according to the river channel width acquisition strategy specifically includes: Obtain the center line of the river channel, and the two end points of the center line of the river channel are respectively recorded as the first point and the second point; The first point is the endpoint of the two end points of the river centerline that is closest to the first end point and the third end point; The second point is the endpoint of the two end points of the river centerline that is closest to the second end point and the fourth end point; Specify the direction from the first point to the second point on the river centerline and the positive direction of the river centerline; On the center line of the river, starting from the first point, the division points are taken in sequence in the positive direction of the center line of the river. The interval between each division point is 30 meters, and the division points are recorded in sequence along the positive direction of the center line of the river as the first center line division point, the second center line division point...the Dth center line division point, where D refers to the number of center line division points.

[0009] Optionally, the acquiring the width of the target river channel according to the river channel width acquisition strategy specifically includes: Obtain the water flow direction at the first midline segmentation point, recorded as the first water flow direction; Draw a straight line through the first midline dividing point that is parallel to the horizontal plane and perpendicular to the first water flow direction, and record it as the first straight line; The intersection point of the first straight line and the first river bank is recorded as the first measurement point of the first river bank, and the intersection point of the first straight line and the second river bank is recorded as the first measurement point of the second river bank; Obtain the water flow direction at the second midline segmentation point, recorded as the second water flow direction; Draw a straight line through the second midline dividing point that is parallel to the horizontal plane and perpendicular to the second water flow direction, and record it as the second straight line; The intersection point of the second straight line and the first river bank is recorded as the second intersection point of the first river bank, and the intersection point of the second straight line and the second river bank is recorded as the second intersection point of the second river bank; Connect the first measuring point of the first river bank and the first measuring point of the second river bank to form a straight line, which is recorded as the first connecting line; Connect the second intersection point of the first river bank and the second intersection point of the second river bank to form a straight line, which is recorded as the second connecting line; If the first connecting line and the second connecting line do not intersect, the second intersection point of the first river bank is recorded as the second measuring point of the first river bank, and the second intersection point of the second river bank is recorded as the second measuring point of the second river bank; Optionally, the acquiring the width of the target river channel according to the river channel width acquisition strategy specifically includes: If the first connecting line intersects with the second connecting line, the measuring point is obtained according to the measuring point obtaining strategy at the time of intersection; Then draw a straight line through the second midline dividing point parallel to the first connecting line and the horizontal plane, recorded as the third connecting line; Draw a straight line between the first and third connecting lines across the center line of the river, parallel to the first connecting line, the third connecting line and the horizontal plane, and with the same distance from the first and third connecting lines, which is recorded as the fourth connecting line; Obtain the distance between the third connecting line and the fourth connecting line, and record it as the auxiliary distance; A straight line parallel to the third connecting line and the horizontal plane is made on the other side of the third connecting line across the center line of the river channel, and the distance from the third connecting line is the auxiliary distance, which is recorded as the fifth connecting line; Obtain the river area between the fourth connecting line and the fifth connecting line, and record it as the auxiliary area; Perform meshing on the auxiliary area; The shape of the grid is a square with a side length of 1 meter; Get the water flow direction at the geometric center of each grid; The second connecting line is rotated with the second central dividing point as the rotation axis when the second connecting line has no intersection with the fourth connecting line and the fifth connecting line; Get all the grids that the second line passes through; For each grid that the second line passes through; Obtain the smaller angle of the two angles formed by the water flow direction at the geometric center of the grid and the second connecting line, which is recorded as the auxiliary angle; Calculate 90 degrees minus the auxiliary angle, and record the result as the intersection angle; Calculate the average of the intersection angles of all grids; When the average value is the smallest, the intersection point of the second connecting line and the first river bank is recorded as the second measuring point of the first river bank, and the intersection point of the second connecting line and the second river bank is recorded as the second measuring point of the second river bank.

[0010] Optionally, the acquiring the width of the target river channel according to the river channel width acquisition strategy specifically includes: Obtain the water flow direction at the third midline segmentation point, recorded as the fourth water flow direction; Draw a straight line through the third midline dividing point that is parallel to the horizontal plane and perpendicular to the fourth water flow direction, and record it as the third straight line; The intersection of the third straight line and the first river bank is recorded as the third intersection of the first river bank, and the intersection of the third straight line and the second river bank is recorded as the third intersection of the second river bank; Connect the second measuring point of the first river bank and the second measuring point of the second river bank to form a straight line, which is recorded as the sixth connecting line; Connect the third intersection point of the first river bank and the third intersection point of the second river bank to form a straight line, which is recorded as the seventh connecting line; If the sixth connecting line and the seventh connecting line do not intersect, the third intersection point of the first river bank is recorded as the third measuring point of the first river bank, and the third intersection point of the second river bank is recorded as the third measuring point of the second river bank; If the sixth connecting line and the seventh connecting line intersect, the third measuring point of the first river bank and the third measuring point of the second river bank corresponding to the segmentation point of the third midline are obtained according to the measuring point acquisition strategy at the time of intersection; Through the above method, the fourth measurement point of the first river bank and the fourth measurement point of the second river bank corresponding to the fourth centerline segmentation point, the fifth measurement point of the first river bank and the fifth measurement point of the second river bank corresponding to the fifth centerline segmentation point are obtained in sequence... The Dth measurement point of the first river bank and the Dth measurement point of the second river bank corresponding to the Dth centerline segmentation point are obtained in sequence.

[0011] Optionally, the acquiring the width of the target river channel according to the river channel width acquisition strategy specifically includes: Use a measuring tape to obtain the measuring tape reading between the first measuring point on the first river bank and the first measuring point on the second river bank, specifically: The starting point of the measuring ruler is located one meter above the first measuring point on the first river bank, and the measuring ruler is pulled so that the straight line formed by the measuring ruler between the first measuring point on the first river bank and the first measuring point on the second river bank is parallel to the horizontal plane. The reading of the measuring ruler one meter above the first measuring point on the second river bank is recorded as the first reading; In the above manner, the second reading between the second measuring point on the first river bank and the second measuring point on the second river bank, the third reading between the third measuring point on the first river bank and the third measuring point on the second river bank, and so on, are obtained in sequence.

[0012] Optionally, the correcting the data measured by the measuring ruler according to the measuring ruler calibration strategy specifically includes: Two movable poles are set on the horizontal ground, and the upper ends of the poles are used to clamp the measuring ruler; When the reading of the measuring ruler between the two poles is the first reading, obtain the distance between the two poles on the ground, recorded as the first distance, and the first distance is the actual distance between the first measuring point on the first river bank and the first measuring point on the second river bank; when the reading of the measuring ruler between the two poles is the second reading, obtain the distance between the two poles on the ground, recorded as the second distance, and the second distance is the actual distance between the second measuring point on the first river bank and the second measuring point on the second river bank…When the reading of the measuring ruler between the two poles is the Dth reading, obtain the distance between the two poles on the ground, recorded as the Dth distance, and the Dth distance is the actual distance between the Dth measuring point on the first river bank and the Dth measuring point on the second river bank.

[0013] The present invention has the following beneficial effects: 1. This three-dimensional digital river simulation method based on remote sensing inversion calculation can effectively eliminate the influence of clouds and shadows and retain the real information of the river by processing the initial remote sensing image using a cloud removal and shadow removal algorithm; the benefit of this process is that by ensuring the clear visibility of the target river, the model's three-dimensional digital reconstruction of the river is more accurate, avoiding erroneous analysis caused by interference from clouds or shadows; this improves the quality of the image and makes subsequent data extraction and simulation more reliable.

[0014] 2. This three-dimensional digital river simulation method based on remote sensing inversion calculation accurately extracts the target river from the image and clearly defines the two banks of the river, which facilitates the subsequent digital river modeling. The advantage of this method is that it improves the accuracy of digital modeling through clear division standards. Further modeling using the real river features in the remote sensing image can not only capture the river contour more accurately, but also reduce human errors, which is particularly important in remote sensing monitoring of large-area rivers.

[0015] 3. This three-dimensional digital river simulation method based on remote sensing inversion calculation can make the river simulation more consistent with the actual terrain changes by calculating the length ratio of the two river banks and adjusting the spacing of the segmentation points based on the ratio. This strategy helps to cope with the different widths and morphological changes on both sides of the river channel, ensuring more refined modeling of each area. Specifically, this processing method solves the differences in river bank morphology in different regions by adaptively adjusting the spacing of segmentation points, making the model more consistent with the actual terrain; at the same time, by connecting each pair of river bank segmentation points and finding their midpoints, and then fitting these midpoints with smooth curves, an accurate river channel centerline can be constructed; this approach effectively avoids the possible human intervention errors in traditional methods, and by curve fitting, the irregularities caused by remote sensing image errors are smoothed, thereby obtaining a more accurate river channel centerline. This can not only effectively reflect the actual morphology of the river channel, but also provide more accurate path data for subsequent three-dimensional modeling.

[0016] 4. This is a three-dimensional digital river simulation method based on remote sensing inversion calculation. In the first step of the river width acquisition strategy, the two endpoints of the river centerline are first determined, namely the "first point" and the "second point". The selection of these two endpoints is based on the distance relationship between the endpoints on both sides of the river. Then, between the two end points of the river centerline, multiple centerline segmentation points are obtained at a certain interval. At each centerline segmentation point, the corresponding water flow direction is determined, and a straight line is made perpendicularly at each segmentation point through the direction. The intersection of this straight line and the two sides of the river is the actual measurement point of the river. This step This step ensures that the measurement is consistent with the actual water flow direction, thus avoiding measurement errors caused by different water flow directions; the water flow direction has an important influence on the shape and width of the river channel, so the measurement line perpendicular to the water flow direction can more realistically reflect the width of the river channel, especially when the water flow direction is curved or non-straight; at each midline division point, the width is determined by the intersection of a straight line perpendicular to the water flow direction and the river bank; this straight line will intersect with the two river banks respectively, and the intersection point is the actual river bank measurement point; then, the distance between these intersection points is measured to obtain the corresponding river channel width value For multiple measuring points, connect the corresponding intersection points to form lines, and further check whether these lines intersect. If there is no intersection, it means that the river width measurement point determined by the water flow direction of the center line segmentation point is correct, and there is no need to find other measuring points; if there is an intersection, it means that the river width measurement point determined by the water flow direction of the center line segmentation point is wrong, and other measuring points need to be found; in the process of finding other measuring points; by taking the segmentation point as the center, demarcating the grid area, making the second line rotate with the second center segmentation point as the rotation axis, when the second line intersects with the fourth line and the fifth line When there is no intersection between the lines; the angle between the water flow direction of the geometric center of all the grids passed by the second line and the smaller of the two angles formed by the second line is recorded as the auxiliary angle; by calculating 90 degrees - the auxiliary angle, it is recorded as the intersection angle, and the average value of all the intersection angles is calculated. The smallest average value represents that the water flow direction in all grids under the second line is basically the same; the intersection point of the second line and the two river banks corresponding to the smallest average value is selected as the measurement point, which can ensure that the selected measurement point can truly reflect the width of the river channel and has strong representativeness, which can play a key role in the simulation.

[0017] 5. This is a three-dimensional digital river simulation method based on remote sensing inversion calculation. By setting up a mobile pole to calibrate the measuring ruler, the real distance of each measuring point can be obtained. When using a measuring ruler to measure the distance, the measuring ruler may sag due to the long distance, resulting in the measuring ruler reading not being the real distance. The advantage of this strategy is that it can eliminate the systematic error that may be caused by the measuring tool, making the final measurement result closer to the actual situation. Through multi-point calibration, the accuracy of remote sensing data in terrain modeling can be effectively improved, especially in wide rivers or complex terrains, where the measurement error may be greater, so this calibration method is particularly important. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the first connecting line and the second connecting line not intersecting with each other in the present invention.

[0019] Figure 2 This is a schematic diagram of the intersection of the first connecting line and the second connecting line of the present invention. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Example, see Figure 1-Figure 2 , a three-dimensional digital river simulation method based on remote sensing inversion calculation, specifically including: Obtain a river channel that needs to be digitally simulated, and record it as a target river channel; An optical remote sensing image of a target river channel is obtained by using optical remote sensing technology, and recorded as an initial remote sensing image; Determine whether the target river channel in the initial remote sensing image is blocked by clouds; If the target river channel in the initial remote sensing image is blocked by clouds, the cloud removal and shadow removal algorithm is used to remove the clouds blocking the target river channel in the initial remote sensing image; The initial remote sensing image processed by the cloud removal and shadow removal algorithm or the initial remote sensing image in which the target river channel is not blocked by clouds is recorded as the target remote sensing image; This three-dimensional digital river simulation method based on remote sensing inversion calculation can effectively eliminate the influence of clouds and shadows and retain the real information of the river by processing the initial remote sensing image using a cloud removal and shadow removal algorithm; the benefit of this process is that by ensuring the clear visibility of the target river, the model's three-dimensional digital reconstruction of the river is more accurate, avoiding erroneous analysis caused by interference from clouds or shadows; this improves the quality of the image and makes subsequent data extraction and simulation more reliable; Obtain two riverbanks of a target river in a target remote sensing image, and record them as a first riverbank and a second riverbank respectively; The two endpoints of the first river bank are recorded as the first endpoint and the second endpoint; The two endpoints of the second river bank are recorded as the third endpoint and the fourth endpoint; The direction from the first end point to the second end point on the first river bank is defined as the positive direction of the first river bank; The direction from the third endpoint to the fourth endpoint on the second river bank is defined as the positive direction of the second river bank; Get the length of the first river bank, recorded as the first length; Get the length of the second river bank, and record it as the second length; This three-dimensional digital river simulation method based on remote sensing inversion calculation can accurately extract the target river from the image and clearly define the two banks of the river, which is convenient for subsequent digital river modeling. The advantage of this method is that it improves the accuracy of digital modeling through clear division standards. Further modeling using the real river features in the remote sensing image can not only capture the river contour more accurately, but also reduce human errors, which is particularly important in remote sensing monitoring of large-area rivers. Obtain the center line of the target river channel according to the river channel center line acquisition strategy; The center line of the target river channel is recorded as the center line of the river channel; The width of the target river channel is obtained according to the river channel width acquisition strategy; Correct the data measured by the measuring ruler according to the measuring ruler calibration strategy; The river channel is digitally simulated using the corrected data.

[0022] The step of obtaining the center line of the target river channel according to the river channel center line obtaining strategy specifically includes: Calculate the first length ÷ the second length and record the result as the riverbank length ratio; Obtain endpoints of the second river bank, wherein the endpoint closest to the first endpoint is the third endpoint, and the endpoint closest to the second endpoint is the fourth endpoint; On the second river bank, starting from the third endpoint, select division points in sequence in the positive direction of the second river bank, with an interval of 10 meters between each division point, and record the division points in sequence along the positive direction of the second river bank as the first division point of the second river bank, the second division point of the second river bank...the Ath division point of the second river bank, where A refers to the number of division points on the second river bank; On the first river bank, starting from the first end point, division points are taken in sequence in the positive direction of the first river bank. The interval between each division point is 10 meters × the ratio of the river bank length, and the division points are recorded in sequence along the positive direction of the first river bank as the first division point of the first river bank, the second division point of the first river bank...the Bth division point of the first river bank, where B refers to the number of division points on the first river bank, and B=A.

[0023] The step of obtaining the center line of the target river channel according to the river channel center line obtaining strategy specifically includes: Connect the first dividing point of the first river bank and the first dividing point of the second river bank to form a first auxiliary line segment, obtain the midpoint of the first auxiliary line segment, and record it as the first midline point; connect the second dividing point of the first river bank and the second dividing point of the second river bank to form a second auxiliary line segment, obtain the midpoint of the second auxiliary line segment, and record it as the second midline point... Connect the Bth dividing point of the first river bank and the Ath dividing point of the second river bank to form the Cth auxiliary line segment, obtain the midpoint of the Ath auxiliary line segment, and record it as the Cth midline point, and C=B=A; Obtain the first midline point, the second midline point, ... the Cth midline point; Fit the first midline point, the second midline point, ... the Cth midline point into a smooth curve; The smooth curve is the center line of the target river channel; This three-dimensional digital river simulation method based on remote sensing inversion calculation can make the river simulation more consistent with the actual terrain changes by calculating the length ratio of the two river banks and adjusting the spacing of the segmentation points based on the ratio. This strategy helps to cope with the different widths and morphological changes on both sides of the river channel, ensuring more refined modeling of each area. Specifically, this processing method solves the differences in river bank morphology in different regions by adaptively adjusting the spacing of segmentation points, making the model more consistent with the actual terrain; at the same time, by connecting each pair of river bank segmentation points and obtaining the midpoint, and then fitting these midpoints with a smooth curve, an accurate river centerline can be constructed; this approach effectively avoids the possible human intervention errors in traditional methods, and through curve fitting, smoothes the irregularities caused by remote sensing image errors, thereby obtaining a more accurate river centerline. This can not only effectively reflect the actual morphology of the river channel, but also provide more accurate path data for subsequent three-dimensional modeling.

[0024] The step of obtaining the width of the target river channel according to the river channel width obtaining strategy specifically includes: Obtain the center line of the river channel, and the two end points of the center line of the river channel are respectively recorded as the first point and the second point; The first point is the endpoint of the two end points of the river centerline that is closest to the first end point and the third end point; The second point is the endpoint of the two end points of the river centerline that is closest to the second end point and the fourth end point; Specify the direction from the first point to the second point on the river centerline and the positive direction of the river centerline; On the center line of the river, starting from the first point, the division points are taken in sequence in the positive direction of the center line of the river. The interval between each division point is 30 meters, and the division points are recorded in sequence along the positive direction of the center line of the river as the first center line division point, the second center line division point...the Dth center line division point, where D refers to the number of center line division points.

[0025] The step of obtaining the width of the target river channel according to the river channel width obtaining strategy specifically includes: Obtain the water flow direction at the first midline segmentation point, recorded as the first water flow direction; Draw a straight line through the first midline dividing point that is parallel to the horizontal plane and perpendicular to the first water flow direction, and record it as the first straight line; The intersection point of the first straight line and the first river bank is recorded as the first measurement point of the first river bank, and the intersection point of the first straight line and the second river bank is recorded as the first measurement point of the second river bank; Obtain the water flow direction at the second midline segmentation point, recorded as the second water flow direction; Draw a straight line through the second midline dividing point that is parallel to the horizontal plane and perpendicular to the second water flow direction, and record it as the second straight line; The intersection point of the second straight line and the first river bank is recorded as the second intersection point of the first river bank, and the intersection point of the second straight line and the second river bank is recorded as the second intersection point of the second river bank; Connect the first measuring point of the first river bank and the first measuring point of the second river bank to form a straight line, which is recorded as the first connecting line; Connect the second intersection point of the first river bank and the second intersection point of the second river bank to form a straight line, which is recorded as the second connecting line; Reference Figure 1 , if the first connecting line and the second connecting line do not intersect, the second intersection point of the first river bank is recorded as the second measuring point of the first river bank, and the second intersection point of the second river bank is recorded as the second measuring point of the second river bank; The step of obtaining the width of the target river channel according to the river channel width obtaining strategy specifically includes: Reference Figure 2 , if the first link and the second link intersect, obtain the measurement point according to the measurement point acquisition strategy at the time of intersection; Then draw a straight line through the second midline dividing point parallel to the first connecting line and the horizontal plane, recorded as the third connecting line; Draw a straight line between the first and third connecting lines across the center line of the river, parallel to the first connecting line, the third connecting line and the horizontal plane, and with the same distance from the first and third connecting lines, which is recorded as the fourth connecting line; Obtain the distance between the third connecting line and the fourth connecting line, and record it as the auxiliary distance; A straight line parallel to the third connecting line and the horizontal plane is made on the other side of the third connecting line across the center line of the river channel, and the distance from the third connecting line is the auxiliary distance, which is recorded as the fifth connecting line; Obtain the river area between the fourth connecting line and the fifth connecting line, and record it as the auxiliary area; Perform meshing on the auxiliary area; The shape of the grid is a square with a side length of 1 meter; Get the water flow direction at the geometric center of each grid; The second connecting line is rotated with the second central dividing point as the rotation axis when the second connecting line has no intersection with the fourth connecting line and the fifth connecting line; Get all the grids that the second line passes through; For each grid that the second line passes through; Obtain the smaller angle of the two angles formed by the water flow direction at the geometric center of the grid and the second connecting line, which is recorded as the auxiliary angle; Calculate 90 degrees minus the auxiliary angle, and record the result as the intersection angle; Calculate the average of the intersection angles of all grids; When the average value is the smallest, the intersection point of the second connecting line and the first river bank is recorded as the second measuring point of the first river bank, and the intersection point of the second connecting line and the second river bank is recorded as the second measuring point of the second river bank.

[0026] The step of obtaining the width of the target river channel according to the river channel width obtaining strategy specifically includes: Obtain the water flow direction at the third midline segmentation point, recorded as the fourth water flow direction; Draw a straight line through the third midline dividing point that is parallel to the horizontal plane and perpendicular to the fourth water flow direction, and record it as the third straight line; The intersection of the third straight line and the first river bank is recorded as the third intersection of the first river bank, and the intersection of the third straight line and the second river bank is recorded as the third intersection of the second river bank; Connect the second measuring point of the first river bank and the second measuring point of the second river bank to form a straight line, which is recorded as the sixth connecting line; Connect the third intersection point of the first river bank and the third intersection point of the second river bank to form a straight line, which is recorded as the seventh connecting line; If the sixth connecting line and the seventh connecting line do not intersect, the third intersection point of the first river bank is recorded as the third measuring point of the first river bank, and the third intersection point of the second river bank is recorded as the third measuring point of the second river bank; If the sixth connecting line and the seventh connecting line intersect, the third measuring point of the first river bank and the third measuring point of the second river bank corresponding to the segmentation point of the third midline are obtained according to the measuring point acquisition strategy at the time of intersection; By the above method, the fourth measurement point of the first river bank and the fourth measurement point of the second river bank corresponding to the fourth midline segmentation point, the fifth measurement point of the first river bank and the fifth measurement point of the second river bank corresponding to the fifth midline segmentation point, and so on and so forth are obtained in sequence; This is a three-dimensional digital river simulation method based on remote sensing inversion calculation. In the first step of the river width acquisition strategy, the two endpoints of the river centerline are first determined, namely the "first point" and the "second point". The selection of these two endpoints is based on the distance relationship between the endpoints on both sides of the river. Then, between the two end points of the river centerline, multiple centerline segmentation points are obtained at a certain interval. At each centerline segmentation point, the corresponding water flow direction is determined, and a straight line is made perpendicularly at each segmentation point through the direction. The intersection of this straight line and the two sides of the river is the actual measurement point of the river. This step confirms This ensures that the measurement is consistent with the actual water flow direction, thereby avoiding measurement errors caused by different water flow directions; the water flow direction has an important influence on the shape and width of the river channel, so the measurement line perpendicular to the water flow direction can more realistically reflect the width of the river channel, especially when the water flow direction is curved or non-straight; at each midline division point, the width is determined by the intersection of a straight line perpendicular to the water flow direction and the river bank; this straight line will intersect with the two river banks respectively, and the intersection point is the actual river bank measurement point; then, the distance between these intersection points is measured to obtain the corresponding river channel width data ; For multiple measuring points, connect the corresponding intersection points to form lines, and further check whether these lines intersect. If there is no intersection, it means that the river width measurement point determined by the water flow direction of the center line segmentation point is correct, and there is no need to find other measuring points; if there is an intersection, it means that the river width measurement point determined by the water flow direction of the center line segmentation point is wrong, and other measuring points need to be found; in the process of finding other measuring points; by taking the segmentation point as the center, demarcating the grid area, making the second line rotate with the second center segmentation point as the rotation axis, when the second line intersects with the fourth line and the fifth line When there is no intersection between the lines; the angle between the water flow direction of the geometric center of all the grids passed by the second line and the smaller of the two angles formed by the second line is recorded as the auxiliary angle; by calculating 90 degrees - the auxiliary angle, it is recorded as the intersection angle, and the average value of all the intersection angles is calculated. The smallest average value represents that the water flow direction in all grids under the second line is basically the same; the intersection point of the second line and the two river banks corresponding to the smallest average value is selected as the measurement point, which can ensure that the selected measurement point can truly reflect the width of the river channel and has strong representativeness, which can play a key role in the simulation.

[0027] The step of obtaining the width of the target river channel according to the river channel width obtaining strategy specifically includes: Use a measuring tape to obtain the measuring tape reading between the first measuring point on the first river bank and the first measuring point on the second river bank, specifically: The starting point of the measuring ruler is located one meter above the first measuring point on the first river bank, and the measuring ruler is pulled so that the straight line formed by the measuring ruler between the first measuring point on the first river bank and the first measuring point on the second river bank is parallel to the horizontal plane. The reading of the measuring ruler one meter above the first measuring point on the second river bank is recorded as the first reading; In the above manner, the second reading between the second measuring point on the first river bank and the second measuring point on the second river bank, the third reading between the third measuring point on the first river bank and the third measuring point on the second river bank, and so on, are obtained in sequence.

[0028] The correcting of the data measured by the measuring ruler according to the measuring ruler calibration strategy specifically includes: Two movable poles are set on the horizontal ground, and the upper ends of the poles are used to clamp the measuring ruler; When the reading of the measuring ruler between the two poles is the first reading, the distance between the two poles on the ground is obtained, recorded as the first distance, which is the real distance between the first measuring point on the first river bank and the first measuring point on the second river bank; when the reading of the measuring ruler between the two poles is the second reading, the distance between the two poles on the ground is obtained, recorded as the second distance, which is the real distance between the second measuring point on the first river bank and the second measuring point on the second river bank…When the reading of the measuring ruler between the two poles is the Dth reading, the distance between the two poles on the ground is obtained, recorded as the Dth distance, which is the real distance between the Dth measuring point on the first river bank and the Dth measuring point on the second river bank; This is a three-dimensional digital river simulation method based on remote sensing inversion calculation. By setting up a mobile pole to calibrate the measuring ruler, the real distance of each measuring point can be obtained. When using a measuring ruler to measure the distance, the measuring ruler may sag due to the long distance, resulting in the measuring ruler reading not being the real distance. The advantage of this strategy is that it can eliminate the systematic error that may be caused by the measuring tool, making the final measurement result closer to the actual situation. Through multi-point calibration, the accuracy of remote sensing data in terrain modeling can be effectively improved, especially in wide rivers or complex terrains, where the measurement error may be greater, so this calibration method is particularly important.

[0029] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0030] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A three-dimensional digital river simulation method based on remote sensing inversion calculation, characterized in that: Specifically include: Obtain a river channel that needs to be digitally simulated, and record it as a target river channel; An optical remote sensing image of a target river channel is obtained by using optical remote sensing technology, and recorded as an initial remote sensing image; Determine whether the target river channel in the initial remote sensing image is blocked by clouds; If the target river channel in the initial remote sensing image is blocked by clouds, the cloud removal and shadow removal algorithm is used to remove the clouds blocking the target river channel in the initial remote sensing image; The initial remote sensing image processed by the cloud removal and shadow removal algorithm or the initial remote sensing image in which the target river channel is not blocked by clouds is recorded as the target remote sensing image; Obtain two riverbanks of a target river in a target remote sensing image, and record them as a first riverbank and a second riverbank respectively; The two endpoints of the first river bank are recorded as the first endpoint and the second endpoint; The two endpoints of the second river bank are recorded as the third endpoint and the fourth endpoint; The direction from the first end point to the second end point on the first river bank is defined as the positive direction of the first river bank; The direction from the third endpoint to the fourth endpoint on the second river bank is defined as the positive direction of the second river bank; Get the length of the first river bank, recorded as the first length; Get the length of the second river bank, and record it as the second length; Obtain the center line of the target river channel according to the river channel center line acquisition strategy; The center line of the target river channel is recorded as the center line of the river channel; The width of the target river channel is obtained according to the river channel width acquisition strategy; Correct the data measured by the measuring ruler according to the measuring ruler calibration strategy; The river channel is digitally simulated using the corrected data.

2. The three-dimensional digital river simulation method based on remote sensing inversion calculation according to claim 1 is characterized in that: The step of obtaining the center line of the target river channel according to the river channel center line obtaining strategy specifically includes: Calculate the first length ÷ the second length and record the result as the riverbank length ratio; Obtain endpoints of the second river bank, wherein the endpoint closest to the first endpoint is the third endpoint, and the endpoint closest to the second endpoint is the fourth endpoint; On the second river bank, starting from the third endpoint, select division points in sequence in the positive direction of the second river bank, with an interval of 10 meters between each division point, and record the division points in sequence along the positive direction of the second river bank as the first division point of the second river bank, the second division point of the second river bank...the Ath division point of the second river bank, where A refers to the number of division points on the second river bank; On the first river bank, starting from the first end point, division points are taken in sequence in the positive direction of the first river bank. The interval between each division point is 10 meters × the ratio of the river bank length, and the division points are recorded in sequence along the positive direction of the first river bank as the first division point of the first river bank, the second division point of the first river bank...the Bth division point of the first river bank, where B refers to the number of division points on the first river bank, and B=A.

3. The three-dimensional digital river simulation method based on remote sensing inversion calculation according to claim 2 is characterized in that: The step of obtaining the center line of the target river channel according to the river channel center line obtaining strategy specifically includes: Connect the first dividing point of the first river bank and the first dividing point of the second river bank to form a first auxiliary line segment, obtain the midpoint of the first auxiliary line segment, and record it as the first midline point; connect the second dividing point of the first river bank and the second dividing point of the second river bank to form a second auxiliary line segment, obtain the midpoint of the second auxiliary line segment, and record it as the second midline point... Connect the Bth dividing point of the first river bank and the Ath dividing point of the second river bank to form the Cth auxiliary line segment, obtain the midpoint of the Ath auxiliary line segment, and record it as the Cth midline point, and C=B=A; Obtain the first midline point, the second midline point, ... the Cth midline point; Fit the first midline point, the second midline point, ... the Cth midline point into a smooth curve; The smooth curve is the center line of the target river channel.

4. The three-dimensional digital river simulation method based on remote sensing inversion calculation according to claim 1 is characterized in that: The step of obtaining the width of the target river channel according to the river channel width obtaining strategy specifically includes: Obtain the center line of the river channel, and the two end points of the center line of the river channel are respectively recorded as the first point and the second point; The first point is the endpoint of the two end points of the river centerline that is closest to the first end point and the third end point; The second point is the endpoint of the two end points of the river centerline that is closest to the second end point and the fourth end point; Specify the direction from the first point to the second point on the river centerline and the positive direction of the river centerline; On the center line of the river, starting from the first point, the division points are taken in sequence in the positive direction of the center line of the river. The interval between each division point is 30 meters, and the division points are recorded in sequence along the positive direction of the center line of the river as the first center line division point, the second center line division point...the Dth center line division point, where D refers to the number of center line division points.

5. The three-dimensional digital river simulation method based on remote sensing inversion calculation according to claim 4 is characterized in that: The step of obtaining the width of the target river channel according to the river channel width obtaining strategy specifically includes: Obtain the water flow direction at the first midline segmentation point, recorded as the first water flow direction; Draw a straight line through the first midline dividing point that is parallel to the horizontal plane and perpendicular to the first water flow direction, and record it as the first straight line; The intersection point of the first straight line and the first river bank is recorded as the first measurement point of the first river bank, and the intersection point of the first straight line and the second river bank is recorded as the first measurement point of the second river bank; Obtain the water flow direction at the second midline segmentation point, recorded as the second water flow direction; Draw a straight line through the second midline dividing point that is parallel to the horizontal plane and perpendicular to the second water flow direction, and record it as the second straight line; The intersection point of the second straight line and the first river bank is recorded as the second intersection point of the first river bank, and the intersection point of the second straight line and the second river bank is recorded as the second intersection point of the second river bank; Connect the first measuring point of the first river bank and the first measuring point of the second river bank to form a straight line, which is recorded as the first connecting line; Connect the second intersection point of the first river bank and the second intersection point of the second river bank to form a straight line, which is recorded as the second connecting line; If the first connecting line and the second connecting line do not intersect, the second intersection point of the first river bank is recorded as the second measuring point of the first river bank, and the second intersection point of the second river bank is recorded as the second measuring point of the second river bank.

6. A three-dimensional digital river simulation method based on remote sensing inversion calculation according to claim 5, characterized in that: The step of obtaining the width of the target river channel according to the river channel width obtaining strategy specifically includes: If the first connecting line intersects with the second connecting line, the measuring point is obtained according to the measuring point obtaining strategy at the time of intersection; Then draw a straight line through the second midline dividing point parallel to the first connecting line and the horizontal plane, recorded as the third connecting line; Draw a straight line between the first and third connecting lines across the center line of the river, parallel to the first connecting line, the third connecting line and the horizontal plane, and with the same distance from the first and third connecting lines, which is recorded as the fourth connecting line; Obtain the distance between the third connecting line and the fourth connecting line, and record it as the auxiliary distance; A straight line parallel to the third connecting line and the horizontal plane is made on the other side of the third connecting line across the center line of the river channel, and the distance from the third connecting line is the auxiliary distance, which is recorded as the fifth connecting line; Obtain the river area between the fourth connecting line and the fifth connecting line, and record it as the auxiliary area; Perform meshing on the auxiliary area; The shape of the grid is a square with a side length of 1 meter; Get the water flow direction at the geometric center of each grid; The second connecting line is rotated with the second central dividing point as the rotation axis when the second connecting line has no intersection with the fourth connecting line and the fifth connecting line; Get all the grids that the second line passes through; For each grid that the second line passes through; Obtain the smaller angle of the two angles formed by the water flow direction at the geometric center of the grid and the second connecting line, which is recorded as the auxiliary angle; Calculate 90 degrees minus the auxiliary angle, and record the result as the intersection angle; Calculate the average of the intersection angles of all grids; When the average value is the smallest, the intersection point of the second connecting line and the first river bank is recorded as the second measuring point of the first river bank, and the intersection point of the second connecting line and the second river bank is recorded as the second measuring point of the second river bank.

7. A three-dimensional digital river simulation method based on remote sensing inversion calculation according to claim 6, characterized in that: The step of obtaining the width of the target river channel according to the river channel width obtaining strategy specifically includes: Obtain the water flow direction at the third midline segmentation point, recorded as the fourth water flow direction; Draw a straight line through the third midline dividing point that is parallel to the horizontal plane and perpendicular to the fourth water flow direction, and record it as the third straight line; The intersection of the third straight line and the first river bank is recorded as the third intersection of the first river bank, and the intersection of the third straight line and the second river bank is recorded as the third intersection of the second river bank; Connect the second measuring point of the first river bank and the second measuring point of the second river bank to form a straight line, which is recorded as the sixth connecting line; Connect the third intersection point of the first river bank and the third intersection point of the second river bank to form a straight line, which is recorded as the seventh connecting line; If the sixth connecting line and the seventh connecting line do not intersect, the third intersection point of the first river bank is recorded as the third measuring point of the first river bank, and the third intersection point of the second river bank is recorded as the third measuring point of the second river bank; If the sixth connecting line and the seventh connecting line intersect, the third measuring point of the first river bank and the third measuring point of the second river bank corresponding to the segmentation point of the third midline are obtained according to the measuring point acquisition strategy at the time of intersection; Through the above method, the fourth measurement point of the first river bank and the fourth measurement point of the second river bank corresponding to the fourth centerline segmentation point, the fifth measurement point of the first river bank and the fifth measurement point of the second river bank corresponding to the fifth centerline segmentation point are obtained in sequence... The Dth measurement point of the first river bank and the Dth measurement point of the second river bank corresponding to the Dth centerline segmentation point are obtained in sequence.

8. The three-dimensional digital river simulation method based on remote sensing inversion calculation according to claim 7 is characterized by: The step of obtaining the width of the target river channel according to the river channel width obtaining strategy specifically includes: Use a measuring tape to obtain the measuring tape reading between the first measuring point on the first river bank and the first measuring point on the second river bank, specifically: The starting point of the measuring ruler is located one meter above the first measuring point on the first river bank, and the measuring ruler is pulled so that the straight line formed by the measuring ruler between the first measuring point on the first river bank and the first measuring point on the second river bank is parallel to the horizontal plane. The reading of the measuring ruler one meter above the first measuring point on the second river bank is recorded as the first reading; In the above manner, the second reading between the second measuring point on the first river bank and the second measuring point on the second river bank, the third reading between the third measuring point on the first river bank and the third measuring point on the second river bank, and so on, are obtained in sequence.

9. The three-dimensional digital river simulation method based on remote sensing inversion calculation according to claim 1 is characterized in that: The correcting of the data measured by the measuring ruler according to the measuring ruler calibration strategy specifically includes: Two movable poles are set on the horizontal ground, and the upper ends of the poles are used to clamp the measuring ruler; When the reading of the measuring ruler between the two poles is the first reading, obtain the distance between the two poles on the ground, recorded as the first distance, and the first distance is the actual distance between the first measuring point on the first river bank and the first measuring point on the second river bank; when the reading of the measuring ruler between the two poles is the second reading, obtain the distance between the two poles on the ground, recorded as the second distance, and the second distance is the actual distance between the second measuring point on the first river bank and the second measuring point on the second river bank…When the reading of the measuring ruler between the two poles is the Dth reading, obtain the distance between the two poles on the ground, recorded as the Dth distance, and the Dth distance is the actual distance between the Dth measuring point on the first river bank and the Dth measuring point on the second river bank.

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