Irregular survey network intersection traversal search method, storage medium and device

Abstract

Provided are an irregular survey network intersection traversal search method, a storage medium, and a device, including: rotating the irregular survey network so that the direction of the main survey line or the secondary survey line is substantially horizontal, where the irregular survey network is an airborne and marine gravity irregular survey network; determining two minimum circumscribed rectangles that are parallel to the vertical and horizontal coordinate axes and respectively enclose the main and secondary survey lines of the survey network; taking out the overlapping rectangle of the two circumscribed rectangles as the search range for the survey network intersections, and using the center point to divide the overlapping rectangle into four sub-rectangles on average; determining whether the product of the number of survey points included in the main and secondary survey lines in each sub-rectangle is greater than a predetermined value. If so, continue to divide the sub-rectangle into four sub-rectangles for recursive processing. If not, output the survey point index of the overlapping area of the envelope rectangles of the main and secondary survey lines within the sub-rectangle. According to the output survey point index, determine the existing intersections and the corresponding survey point information. This method can improve the search efficiency while improving the accuracy rate.

Description

[0001] This invention is a divisional application of Chinese patent application number ZL202010771152.7, and invention name is “Method and device for searching intersection points of sea and air gravity measurement network”, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0002] The invention belongs to the field of sea and air gravity exploration, and relates to an irregular survey network intersection traversal search method, storage medium and equipment. Background Art

[0003] In sea-air gravity measurements (sea-air gravity is a general term for sea surface and aerial gravity), data is often a series of discrete points. Each survey line has a large number of points. The traditional one-by-one comparison traversal search method is very inefficient in finding intersection points.

[0004] Chinese patent ZL201810100320.2 discloses a non-traversal search method for intersections in an aerial gravity network. This method first calculates an approximate intersection point and searches for the nearest point on the survey line and the cutting line. Based on the target point found, the approximate intersection point is recalculated using a jump approximation method, approximating the intersection a second time. The target point is then determined to determine if it truly intersects. If not, it is fine-tuned and slid until it fully intersects. This method avoids traditional traversal search methods, significantly improving computational efficiency and effectively reducing the time required to search for intersections in an aerial gravity network.

[0005] Although the above patented method improves the search efficiency to a certain extent, for large-scale measurement networks, its search efficiency still needs to be further improved. Moreover, for irregular measurement networks, this method is not generally applicable and cannot search all intersections, which will reduce the accuracy.

[0006] Therefore, it is necessary to study an irregular network intersection traversal search method, storage medium and device to solve one or more of the above technical problems. Summary of the Invention

[0007] In order to solve one or more technical problems in the prior art, a method for searching intersections of a sea-air gravity network is provided, which is characterized by comprising:

[0008] Determine the two minimum circumscribed rectangles parallel to the vertical and horizontal coordinate axes, respectively enclosing the main and auxiliary survey lines of the survey network;

[0009] Determine the overlapping rectangle of the two circumscribed rectangles as the search range for the intersection of the measurement network;

[0010] Use the center point to divide the overlapping rectangle into four sub-rectangles;

[0011] Determine whether the product of the number of measurement points included in the main and secondary survey lines within each sub-rectangle is greater than a predetermined value. If so, continue to divide the sub-rectangle into four sub-rectangles for recursive processing. If not, output the measurement point indices within the overlapping region of the envelope rectangles of the main and secondary survey lines within the sub-rectangle.

[0012] It can be understood that the measurement point index mentioned refers to the array subscript used to store information such as the position of the measurement point.

[0013] Based on the measurement point indices, determine the existing intersection points and the corresponding measurement points.

[0014] According to another aspect of the present invention, the predetermined value can be adaptively selected according to the scale of the survey network. Preferably, the predetermined value is 5000.

[0015] According to another aspect of the present invention, the survey network is an irregular survey network, and the irregular survey network is rotated so that the direction of the main survey line or the secondary survey line is basically horizontal.

[0016] According to another aspect of the present invention, the determinant method, the projection method, or the vector area method is used to determine the existing intersection points and the corresponding measurement points.

[0017] According to another aspect of the present invention, the determinant method is used for solving. Let the coordinates of the four endpoints of the two line segments be (x1, y1), (x2, y2), (x3, y3), (x4, y4), then the parametric equations of the straight lines where the two line segments are located are respectively

[0018] x = x1 + t1 * (x2 - x1)

[0019] y = y1 + t1 * (y2 - y1)

[0020] x = x3 + t2 * (x4 - x3)

[0021] y = y3 + t2 * (y4 - y3)

[0022] If the two straight lines intersect, then x and y are the coordinates of the intersection point, and t1 and t2 are the parameters to be solved. Exactly four equations and four unknowns, written in matrix form as follows:

[0023]

[0024] When 0 ≤ t1 ≤ 1 and 0 ≤ t2 ≤ 1, the intersection point is on the line segment.

[0025] According to another aspect of the present invention, retain the measurement point indices within the overlapping region of the envelope rectangles of the main and secondary survey lines within the sub-rectangle. The envelope rectangle mentioned refers to the set of the minimum circumscribed rectangles of all line segments included in the survey line.

[0026] According to another aspect of the present invention, the rectangular recursive dissection is an adaptive dissection. By using the product of the number of measurement points on the main and secondary survey lines within the current rectangle as a determination condition, the more densely measured areas are dissected more finely. Additionally, by using the overlapping area of the enclosing rectangles to select the index, the magnitude of the finally obtained index is comparable to that of the intersection points. Through search queries and size comparisons, a large amount of redundant calculation and determination processes are avoided, greatly improving the efficiency of traversing and searching for intersection points.

[0027] According to yet another aspect of the present invention, there is also provided a computer-readable storage medium, characterized in that a computer program is stored in the computer-readable storage medium, and the computer program is adapted to be loaded and executed by a processor so that a computer device having the processor executes the foregoing method.

[0028] According to yet another aspect of the present invention, there is also provided a computer device, characterized in that it includes: a processor and a memory;

[0029] The processor is connected to the memory, wherein the memory is used to store a computer program, and the processor is used to call the computer program so that the computer device executes the foregoing method.

[0030] According to another aspect of the present invention, there is also provided a sea-air gravity survey network intersection point search device, characterized in that it includes:

[0031] A first module for determining the smallest circumscribed rectangles that respectively enclose the main and secondary survey lines of the survey network and are parallel to the vertical and horizontal coordinate axes;

[0032] A second module for determining the overlapping rectangle of the two circumscribed rectangles as the search range for the intersection points of the survey network;

[0033] A third module for equally dividing the overlapping rectangle into four sub-rectangles by using the center point;

[0034] A fourth module for determining whether the product of the number of measurement points included in the main and secondary survey lines within each sub-rectangle is greater than a predetermined value. If so, the sub-rectangle is further divided into four sub-rectangles for recursive processing. If not, the measurement point index within the overlapping area of the enclosing rectangles of the main and secondary survey lines within the sub-rectangle is output;

[0035] A fifth module for determining the existing intersection points and corresponding measurement points according to the measurement point index.

[0036] According to another aspect of the present invention, the predetermined value can be adaptively selected according to the scale of the survey network. Preferably, the predetermined value is 5000.

[0037] According to another aspect of the present invention, the survey network is an irregular survey network, and the irregular survey network is rotated so that the direction of the main survey line or the secondary survey line is basically horizontal.

[0038] According to another aspect of the present invention, the fifth module is used to determine the existing intersection points and corresponding measurement points according to the measurement point index by using the determinant method, the projection method or the vector area method.

[0039] Compared with the prior art, the present invention has the following technical effects: improving the search efficiency; improving the search accuracy; being able to generally adapt to any type of airborne and marine gravity measurement network; especially for irregular measurement networks, the present invention has obvious advantages in terms of accuracy and / or efficiency compared with other methods. Description of the Drawings

[0040] Figure 1 It is a flowchart of a method for searching intersection points of an airborne and marine gravity measurement network according to a preferred embodiment of the present invention;

[0041] Figure 2 It is an application example of a method for searching intersection points of an airborne and marine gravity measurement network according to a preferred embodiment of the present invention;

[0042] Figure 3 It is a schematic diagram of coincidence judgment (i.e., determining whether the minimum circumscribed rectangle of the main measurement line and the minimum circumscribed rectangle of the secondary measurement line in each sub-rectangle coincide) according to a preferred embodiment of the present invention;

[0043] Figure 4 It is a schematic diagram of a method for solving intersection points according to a preferred embodiment of the present invention;

[0044] Figure 5 For Figure 2 the design parameters of the data block in the application example;

[0045] Figure 6 It is a schematic diagram of a method for retaining the measurement point index of the coincidence area within the sub-rectangle according to a preferred embodiment of the present invention;

[0046] Figure 7 It is another application example of a method for searching intersection points of an airborne and marine gravity measurement network according to a preferred embodiment of the present invention;

[0047] Figure 8 For Figure 7 the search process (and result) schematic diagram in the case of the unrotated measurement network in the application example;

[0048] Figure 9 For Figure 7 the search process (and result) schematic diagram after rotating the measurement network in the application example;

[0049] Figure 10 For Figure 9 the comparison table of the search efficiency between the search method in and the existing search methods;

[0050] Figure 11 Flow chart of a method for searching intersection points of a sea - air gravity measurement network according to another preferred embodiment of the present invention. Detailed implementation manners

[0051] The following combines the accompanying drawings to describe the best implementation manner of the present invention through preferred embodiments. The specific implementation manner here is to describe the present invention in detail and should not be construed as a limitation of the present invention. Without departing from the spirit and essential scope of the present invention, various deformations and modifications can be made, and all of these should be included within the protection scope of the present invention.

[0052] Embodiment 1

[0053] See Figures 1-4 , where Figure 1 is a flow chart of a method for searching intersection points of a sea - air gravity measurement network according to a preferred embodiment of the present invention; Figure 2 is an application example of a method for searching intersection points of a sea - air gravity measurement network according to a preferred embodiment of the present invention; Figure 3 is a schematic diagram of coincidence judgment (i.e., determining whether the minimum enclosing rectangle of the main survey line and the minimum enclosing rectangle of the secondary survey line in each sub - rectangle coincide) according to a preferred embodiment of the present invention; Figure 4 is a schematic diagram of a method for solving intersection points according to a preferred embodiment of the present invention.

[0054] See Figure 1 , according to a preferred implementation manner of the present invention, a method for searching intersection points of a sea - air gravity measurement network is provided, which is characterized by including:

[0055] Determine the minimum circumscribed rectangle parallel to the vertical and horizontal coordinate axes that encloses the entire measurement network;

[0056] Divide the entire measurement network into four sub - rectangles with the center of the minimum circumscribed rectangle;

[0057] Determine whether the minimum enclosing rectangle of the main survey line and the minimum enclosing rectangle of the secondary survey line in each sub - rectangle coincide. If they coincide, retain the corresponding sub - rectangle; otherwise, exclude it;

[0058] Determine whether the product of the number of main and secondary survey points in the retained sub - rectangle is less than a predetermined value. If so, output the index of the survey points in the retained sub - rectangle; otherwise, continue to divide the retained sub - rectangle into four sub - rectangles for loop processing until the index of the survey points in the retained sub - rectangle is output;

[0059] According to the survey point index, determine the existing intersection points and the corresponding survey points.

[0060] It should be noted that Figure 1The method of "constructing a system of linear equations and solving the equations to determine the existing intersection points and corresponding measuring points" shown in [the figure] is only one implementation manner for determining the existing intersection points and corresponding measuring points, but the present invention is not limited thereto. For example, a projection method, a vector area method, etc. can also be adopted.

[0061] It can be understood that the minimum circumscribed rectangle of the main measuring line and the minimum circumscribed rectangle of the secondary measuring line are also parallel to the vertical and horizontal coordinate axes. By directly excluding the sub-rectangles without overlapping parts, the present invention can greatly shorten the search time and improve the search efficiency. At the same time, the search process of the present invention covers the entire effective measuring network area and can search out all the intersection points therein.

[0062] Preferably, the predetermined value n in the final determination condition represents the product of the number of measuring points of the main and secondary measuring lines in the current rectangle. The advantage of using the product is that if there is only one type of measuring line in the current rectangle, the product n is 0, and the intersection possibility of the sub-rectangle can be directly excluded, improving the efficiency. Generally speaking, for a measuring network with more than one million measuring points, n can be intelligently determined according to the scale of the measuring network. Usually, n is about 30,000. For a small-scale measuring network, n can be appropriately set smaller, usually about 3,000.

[0063] According to another preferred embodiment of the present invention, refer to Figure 3 [the figure], which shows a schematic diagram for determining whether the minimum circumscribed rectangle of the main measuring line and the minimum circumscribed rectangle of the secondary measuring line in each sub-rectangle overlap. Specifically, in the left sub-rectangle, there are secondary measuring line 1 and main measuring line 2. The minimum circumscribed rectangle of secondary measuring line 1 and the minimum circumscribed rectangle of main measuring line 2 have an overlapping area, so the left sub-rectangle is retained. On the contrary, in the right sub-rectangle, there is no overlapping area, so it is excluded.

[0064] According to another preferred embodiment of the present invention, the entire measuring network contains one million measuring points, and the predetermined value is set between 3,000 and 30,000. For example, the entire measuring network contains several million or more measuring points, such as three million or more measuring points. The predetermined value is, for example, set to 8,000, 10,000, or 15,000, etc.

[0065] According to another preferred embodiment of the present invention, the measuring network is an irregular measuring network. It should be noted that a regular measuring network refers to a measuring network in which the main and secondary measuring lines are orthogonal. The method of the present invention has good adaptability to irregular measuring networks and has higher search efficiency and accuracy compared with other existing methods.

[0066] Refer to Figure 2, which shows an example of the method of the present invention applied to an irregular survey network (such as an inclined survey network). Specifically, the inclined survey network includes 5 secondary survey lines 1 and 26 primary survey lines 2. The airborne gravity measurement EN01 data block includes the survey line numbers, sampling times, latitudes, longitudes, geodetic heights, and absolute gravity values of the observation points, with a total of 102,844 data points. See Figure 5 , in which the design parameters of the EN01 data block are given.

[0067] According to another preferred embodiment of the present invention, the determinant method, projection method, or vector area method is used to determine the existing intersection points and corresponding measurement points. For example, as Figure 4 shown, in the vector area method, according to the obtained measurement point indices where intersection points may exist, the straddle determination of line segments is performed through the positive and negative of the vector area, and the indices passing the straddle determination are solved. Generally, the counterclockwise vector area is taken as positive, and the clockwise vector area is taken as negative. The condition for straddle determination is that the product of the two vector areas is not greater than 0. If the straddle determination is passed twice, that is, △P1P2Q1 * △P1P2Q2 ≤ 0 and △Q1Q2P1 * △Q1Q2P2 ≤ 0 are satisfied, then there is an intersection point between line segments P1P2 and Q1Q2; otherwise, there is no intersection point between the two line segments.

[0068] According to another preferred embodiment of the present invention, the determinant method is used for solution. Let the coordinates of the four endpoints of the two line segments be (x1, y1), (x2, y2), (x3, y3), (x4, y4), then the parametric equations of the straight lines where the two line segments are located are respectively

[0069] x = x1 + t1 * (x2 - x1)

[0070] y = y1 + t1 * (y2 - y1)

[0071] x = x3 + t2 * (x4 - x3)

[0072] y = x4 + t2 * (y-4 - y3)

[0073] If the two straight lines intersect, then x and y are the coordinates of the intersection point, and t1 and t2 are the parameters to be solved. Exactly four equations and four unknowns, written in matrix form as follows:

[0074]

[0075] When 0 ≤ t1 ≤ 1 and 0 ≤ t2 ≤ 1, the intersection point is on the line segment.

[0076] According to another preferred embodiment of the present invention, the overlapping area within the sub-rectangle is retained as the corresponding sub-rectangle. Compared with directly retaining the entire sub-rectangle as the retained sub-rectangle, using the overlapping area within the sub-rectangle as the range for extracting indexes further reduces the number of indexes. Specifically, when the product of the number of main and secondary measurement points within the retained sub-rectangle is less than a predetermined value, the measurement point indexes of the overlapping area (the first overlapping area) within the retained sub-rectangle are output.

[0077] Preferably, referring to Figure 6 , the overlapping area 7 (the first overlapping area) within the sub-rectangle is obtained by decomposition through the foregoing steps, where there are intersection points between the secondary measurement line 1 and the main measurement line 2. To further improve the search efficiency, the minimum circumscribed rectangle 3 of each unit measurement line segment (i.e., the line segment between two adjacent measurement points) on the secondary measurement line 1 and the minimum circumscribed rectangle 4 of each unit measurement line segment (i.e., the line segment between two adjacent measurement points) on the main measurement line 2 are further determined. According to the circumscribed rectangles 3 and 4, the overlapping area (the second overlapping area) with intersection points is determined, and finally the measurement point indexes of this overlapping area (the second overlapping area) are extracted. It can be understood that the intersection points can only appear in the overlapping part of the main and secondary measurement line envelopes (circumscribed) rectangles, that is, corresponding to Figure 6 the endpoint indexes (the second overlapping area) of the two first rectangles 6 and the second rectangle 5 in Figure 6 . It should be noted that for the line segments spanning the boundary of the overlapping area, the endpoint outside the overlapping area will also be extracted. Determining at least 4 endpoint (two line segments) indexes is required to determine 1 intersection point. Figure 6 Five endpoint indexes are extracted in . Generally, the order of magnitude of the finally extracted index quantity is basically the same as that of the index quantity required to determine the actual intersection points, which verifies the accuracy and efficiency of this search method to a certain extent. By combining rectangular decomposition and the overlapping area, the efficiency of searching for intersection points is greatly improved, and at the same time, the situation where some intersection points may be missed by other methods is avoided. Using the present invention, it takes 0.28 s to find all the intersection points of a measurement network with about 100,000 measurement points such as EN01.

[0078] According to another preferred embodiment of the present invention, a device for searching intersection points of a sea-air gravity measurement network is further provided, which is characterized by including:

[0079] A first module for determining the minimum circumscribed rectangle parallel to the vertical and horizontal coordinate axes and enclosing the entire measurement network;

[0080] A second module for dividing the entire measurement network into four sub-rectangles with the center of the minimum circumscribed rectangle;

[0081] A third module for determining whether the minimum circumscribed rectangle of the main measurement line and the minimum circumscribed rectangle of the secondary measurement line in each sub-rectangle overlap. If they overlap, the corresponding sub-rectangle is retained; otherwise, it is excluded.

[0082] The fourth module is used to determine whether the product of the number of main and secondary measurement points in the retained sub-rectangle is less than a predetermined value. If so, it outputs the measurement point indexes within the retained sub-rectangle; otherwise, the retained sub-rectangle is further divided into four sub-rectangles for cyclic processing until the measurement point indexes within the retained sub-rectangle are output.

[0083] The fifth module is used to determine the existing intersection points and corresponding measurement points according to the measurement point indexes.

[0084] According to another preferred embodiment of the present invention, the entire measurement network contains millions of measurement points, and the predetermined value is set between 3000 and 30000.

[0085] According to another preferred embodiment of the present invention, the measurement network is an irregular measurement network. Preferably, the device further includes a sixth module for rotating the irregular measurement network so that the main measurement line or the secondary measurement line direction is substantially horizontal.

[0086] According to another preferred embodiment of the present invention, the fifth module is used to determine the existing intersection points and corresponding measurement points according to the measurement point indexes by using the determinant method, the projection method or the vector area method.

[0087] According to another preferred embodiment of the present invention, the measurement network data file can store gravity measurement values at a fixed sampling interval, including the time, longitude and latitude of the measurement points and their gravity values, etc. The intersection point search uses horizontal coordinates (such as longitude and latitude, local coordinates, etc.). The track line can be approximately represented by connecting several points in the plane coordinates. By forming a line segment with adjacent two measurement points, a large number of line segment sequences can be obtained. The essence of obtaining the intersection points is to judge whether these line segments intersect (determine the positions or indexes of the four endpoints of the two line segments for determining the intersection points) and calculate the coordinates of the corresponding intersection points.

[0088] According to another preferred embodiment of the present invention, there is also provided a computer-readable storage medium, characterized in that a computer program is stored in the computer-readable storage medium, and the computer program is suitable for being loaded and executed by a processor so that a computer device having the processor executes the foregoing method.

[0089] According to another preferred embodiment of the present invention, there is also provided a computer device, characterized in that it includes: a processor and a memory;

[0090] The processor is connected to the memory, wherein the memory is used to store a computer program, and the processor is used to call the computer program so that the computer device executes the foregoing method.

[0091] Compared with the prior art, the present invention has the following technical effects: improving the search efficiency; improving the search accuracy; being able to be generally applicable to any type of survey network; especially for an irregular survey network, the present invention has obvious advantages in terms of accuracy and / or efficiency compared with other methods.

[0092] Embodiment 2

[0093] Based on Embodiment 1, for an irregular survey network, i.e., a non-orthogonal survey network, the search method of the present invention is further optimized in Embodiment 2 to improve the search efficiency. The same parts as in Embodiment 1 are omitted here.

[0094] The difference from Embodiment 1 is that before performing the rectangular decomposition, the type of the survey network is judged. When it is determined that the survey network is an irregular survey network, i.e., a non-orthogonal survey network, the survey network is rotated so that the direction of the survey line (such as the main survey line) is approximately horizontal. This can improve the efficiency of the rectangular decomposition.

[0095] Next, taking the AS08 data block of the United States National Geodetic Survey as an example, an illustration is given. Refer to Figures 7-10 , Figure 7 is another application example of the cross-point search method for the sea-air gravity survey network according to a preferred embodiment of the present invention; Figure 8 is Figure 7 a schematic diagram of the search process (and results) in the case where the survey network is not rotated in the application example in Figure 9 is Figure 7 a schematic diagram of the search process (and results) after rotating the survey network in the application example in Figure 10 is Figure 9 a comparison table of the search efficiency between the search method in Figure 7 As shown in Figure 7 gives the design parameters of the AS08 data block.

[0096] Refer to Figure 8 , which shows the initial survey network without rotation, with 48 main survey lines and 13 secondary survey lines. As Figure 8 shown, it can be seen that the outer rectangle quickly converges to near the cross-point and performs adaptive encryption.

[0097] Refer to Figure 9, which shows the rotated survey grid. When the main survey line 2 is rotated to an approximately horizontal direction, the circumscribed rectangle of the entire survey grid is smaller, and the query, comparison, and decomposition efficiency of the rectangle decomposition are higher. In actual calculation, the index generation efficiency after rotation is increased by 30%. Since the measured point index is ultimately utilized, only the measured point indexes in the overlapping area need to be taken out, and the intersection points can be calculated using the coordinates of the unrotated survey grid corresponding to the indexes, so that the calculation accuracy will not be lost due to the rotated coordinates. As Figure 10 shown, in which the search efficiencies of different methods for the AS08 survey grid are compared. The method of the present invention takes less search time, 8.8 s, compared with other methods, and the correct rate is as high as 100%.

[0098] Embodiment 3

[0099] The content of this Embodiment 3 can be combined with the content of Embodiments 1-2 to generate another embodiment. Among them, the process in Embodiment 1 is further optimized, the initial search range is reduced, and the determination of the overlapping area is integrated into the extraction of the main and auxiliary survey line envelope rectangle indexes of the sub-rectangles, further improving the search efficiency.

[0100] According to another preferred embodiment of the present invention, referring to Figure 11 , a method for searching intersection points of a sea-air gravity survey grid is provided, which is characterized by including:

[0101] Determine the smallest circumscribed rectangles parallel to the vertical and horizontal coordinate axes, which respectively enclose the main and auxiliary survey lines of the survey grid;

[0102] Determine the overlapping rectangle (overlapping area) of the two circumscribed rectangles as the search range for the intersection points of the survey grid;

[0103] Use the center point (divide equally based on the center point) to divide the overlapping rectangle into four sub-rectangles;

[0104] Determine whether the product of the number of measured points included in the main and auxiliary survey lines in each sub-rectangle is greater than a predetermined value. If so, continue to divide the sub-rectangle into four sub-rectangles for recursive processing. If not, output (extract) the measured point indexes in the overlapping area of the main and auxiliary survey line envelope rectangles in the sub-rectangle;

[0105] According to the measured point indexes, determine the existing intersection points and the corresponding measured points.

[0106] It can be understood that, as Figure 6 shown, the envelope rectangle refers to the set of the smallest circumscribed rectangles 3 and 4 of all the line segments included in the survey line. The envelope rectangle corresponding to the main survey line 2 is rectangle 4, and the envelope rectangle corresponding to the auxiliary survey line 1 is rectangle 3. The overlapping area (overlapping rectangle) of all the line segments' smallest circumscribed rectangles 3 and 4 is Figure 6The overlapping area (overlapping rectangle) of rectangle 5 and rectangle 6 in it. The calculation of the envelope rectangle overlapping area is an advanced usage based on the overlapping judgment in Figure 3 and is realized by traversing and comparing sizes in the current rectangle.

[0107] According to another preferred embodiment of the present invention, the predetermined value can be adaptively selected according to the scale of the survey network. Preferably, the predetermined value is 5000. In this way, automatic encrypted rectangular subdivision near the intersection points can be realized.

[0108] According to another preferred embodiment of the present invention, the survey network is an irregular survey network, and the irregular survey network is rotated so that the main survey line or the secondary survey line direction is basically horizontal.

[0109] According to another preferred embodiment of the present invention, the determinant method, the projection method or the vector area method is used to determine the existing intersection points and the corresponding survey points.

[0110] According to another preferred embodiment of the present invention, the determinant method is used for solving. Let the four endpoint coordinates of the two line segments be (x1, y1), (x2, y2), (x3, y3), (x4, y4), then the parametric equations of the straight lines where the two line segments are located are respectively

[0111] x = x1 + t1 * (x2 - x1)

[0112] y = y1 + y1 * (y2 - y1)

[0113] x = x3 + t2 * (x4 - x3)

[0114] y = y3 + t2 * (y4 - y3)

[0115] If the two straight lines intersect, then x and y are the intersection point coordinates, and t1 and t2 are the parameters to be solved. Exactly four equations and four unknowns, written in matrix form as follows:

[0116]

[0117] When 0 ≤ t1 ≤ 1 and 0 ≤ t2 ≤ 1, the intersection point is on the line segment. Preferably, the information of the intersection point and the corresponding survey point is retained, and the intersection points outside the line segment are not retained.

[0118] According to another preferred embodiment of the present invention, the survey point indexes within the overlapping area of the envelope rectangles of the main and secondary survey lines in the sub-rectangle are retained (extracted). The envelope rectangle refers to the set of the smallest circumscribed rectangles of all line segments included in the survey lines.

[0119] According to another preferred embodiment of the present invention, there is also provided a sea-air gravity survey network intersection point search device, which is characterized by including:

[0120] The first module is used to determine two minimum circumscribed rectangles that are parallel to the vertical and horizontal coordinate axes and respectively enclose the main and auxiliary survey lines of the survey network;

[0121] The second module is used to determine the overlapping rectangle of the two circumscribed rectangles as the search range for the intersection points of the survey network;

[0122] The third module is used to divide the overlapping rectangle (search range for the intersection points of the survey network) into four sub-rectangles evenly by using the center point;

[0123] The fourth module is used to determine whether the product of the number of measurement points included in the main and auxiliary survey lines in each sub-rectangle is greater than a predetermined value. If so, the sub-rectangle is further divided into four sub-rectangles for recursive processing. If not, the measurement point indexes within the overlapping area of the envelope rectangles of the main and auxiliary survey lines in the sub-rectangle are output (extracted);

[0124] The fifth module is used to determine the existing intersection points and corresponding measurement points according to the measurement point indexes.

[0125] According to another preferred embodiment of the present invention, the predetermined value can be adaptively selected according to the scale of the survey network. Preferably, the predetermined value is 5000.

[0126] According to another preferred embodiment of the present invention, the survey network is an irregular survey network. The search device further includes a sixth module for rotating the irregular survey network so that the direction of the main survey line or the auxiliary survey line is basically horizontal.

[0127] According to another preferred embodiment of the present invention, the fifth module is used to determine the existing intersection points and corresponding measurement points according to the measurement point indexes by using the determinant method, the projection method or the vector area method.

[0128] Compared with the prior art, the present invention has the following technical effects: improving the search efficiency; improving the search accuracy; being able to be generally adapted to any type of survey network; especially for an irregular survey network, the present invention has obvious advantages in terms of accuracy and / or efficiency compared with other methods.

[0129] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An irregular survey network intersection traversal search method, characterized in that Including: Rotating the irregular survey network so that the direction of the main survey line or the secondary survey line is substantially horizontal, where the irregular survey network is an airborne gravity irregular survey network; Determining two minimum circumscribed rectangles parallel to the vertical and horizontal coordinate axes and respectively enclosing the main and secondary survey lines of the survey network; Determining the overlapping rectangle of the two circumscribed rectangles as the search range for the intersection points of the survey network; Dividing the overlapping rectangle into four sub-rectangles evenly by the center point; Determining whether the product of the number of measurement points included in the main and secondary survey lines in each sub-rectangle is greater than a predetermined value. If so, the sub-rectangle is further divided into four sub-rectangles for recursive processing. If not, the measurement point indexes within the overlapping area of the circumscribed rectangles of the main and secondary survey lines in the sub-rectangle are taken out; Determining the existing intersection points and their corresponding measurement points according to the measurement point indexes; Among them, the determinant method is used to solve and determine the existing intersection points and the corresponding measurement points. Let the four endpoint coordinates of the two line segments be (x1, y1), (x2, y2), (x3, y3), (x4, y4), then the parametric equations of the straight lines where the two line segments are located are respectively x = x1 + t1 * (x2 - x1) y = y1 + t1 * (y2 - y1) x = x3 + t2 * (x4 - x3) y = y3 + t2 * (y4 - y3) If the two straight lines intersect, then x and y are the intersection coordinates, and t1 and t2 are the parameters to be solved. Exactly four equations and four unknowns, written in matrix form as follows: When 0 ≤ t1 ≤ 1 and 0 ≤ t2 ≤ 1, the intersection point is on the line segment, and the intersection point and the corresponding measurement point information are retained, and the intersection points outside the line segment are not retained.

2. The method according to claim 1, wherein The predetermined value is adaptively selected according to the scale of the survey network, so as to realize the automatic encrypted rectangular subdivision near the intersection points.

3. The method according to claim 2, wherein The predetermined value is 5000.

4. The method according to any one of claims 1 to 3, characterized in that Taking out the measurement point indexes within the overlapping area of the circumscribed rectangles of the main and secondary survey lines in the sub-rectangle, where the circumscribed rectangle refers to the set of the minimum circumscribed rectangles of all line segments included in the survey line.

5. A computer-readable storage medium, characterized in that, A computer program is stored in the computer-readable storage medium, and the computer program is suitable for being loaded and executed by a processor, so that a computer device having the processor executes the method according to any one of claims 1-4.

6. A computer device, characterized in that, Including: A processor and a memory; The processor is connected to the memory, where the memory is used to store a computer program, and the processor is used to call the computer program, so that the computer device executes the method according to any one of claims 1-4.

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