A route planning method based on communication link visibility check

Abstract

This invention discloses a route planning method based on communication link line-of-sight inspection, which includes the following steps: designing an initial route and collecting waypoints along the initial route; connecting ground stations with adjacent waypoints. 、 A line-of-sight plane is obtained by connecting the points sequentially. Several line-of-sight points are then identified within this plane. The communication link visibility check of each waypoint is evaluated by checking if its height is greater than or equal to the corresponding elevation data. This process is repeated for each waypoint until all waypoints pass the communication link visibility check, resulting in a route with good communication link visibility. This invention, through a surface matrix comparison method, reduces the error in the communication link visibility check, making it more reliable. Furthermore, it allows for the checking of the communication link visibility of all waypoints on the route, and the adjustment of the positions of waypoints with poor communication link visibility to obtain a route with good communication link visibility.

Description

Technical Field

[0001] This invention belongs to the field of communication link visibility technology, and in particular relates to a route planning method based on communication link visibility inspection. Background Technology

[0002] With the development of drone technology, drones are playing an increasingly important role in various aspects of society, including logistics, surveying and mapping, emergency response, power supply, and firefighting. A drone system mainly consists of four parts: the aircraft platform, the mission payload, the communication link, and the ground station. Among these, communication link obstruction is the most significant factor affecting the actual operational range of the data link. Clear line-of-sight (LOS) of the communication link is a necessary condition for ensuring controlled drone flight and stable data transmission. Therefore, the LOS traversal conditions must be considered when designing drone flight routes and selecting takeoff and landing sites. Currently, the assessment of LOS traversal conditions lacks rigorous and accurate calculations, leading to unscientific and unreasonable route design and takeoff and landing site selection. This can cause problems such as excessively high flight altitudes, loss of remote control during flight, and lower-than-expected image transmission quality, especially noticeable in mountainous areas with significant terrain variations.

[0003] To address the aforementioned problems, some researchers have proposed solutions. For example, the UAV data link line-of-sight evaluation method, readable storage medium, and terminal device announced in Chinese Patent Publication No. CN112004237B includes flight path sampling, line-of-sight sampling, calculation of line-of-sight at each viewpoint, calculation of total line-of-sight rate, and line-of-sight evaluation. Although this solution can achieve line-of-sight evaluation of the communication link, it still has the following problems:

[0004] (1) In this scheme, the line of sight sampling is defined as the line of sight connecting the route sampling point and the ground station. The line of sight is sampled at a preset sampling interval. However, the radio wave is not a straight line in the actual transmission process, but is transmitted in the first Fresnel zone. Even if the obstruction does not block the geometric line connecting the transmitting and receiving points, as long as the obstruction enters the first Fresnel zone, the field strength of the receiving point will be affected, and the line of sight of the communication link will be misjudged.

[0005] (2) In this scheme, the viewpoint set is represented as {Bvi, Lvi, Hvi, i∈[1,m]}, where Hvi represents the height of the i-th viewpoint. The formula used in this scheme to calculate the influence of the Fresnel transmission channel on the height is: In the formula, the corrected viewpoint height is Hvi-Δ. If the corrected viewpoint height Hvi-Δ is less than the ground height at the corresponding latitude and longitude, it means that the line of sight is not visible due to the influence of the Fresnel transmission channel. Otherwise, the line of sight is visible. The corrected viewpoint height Hvi-Δ in this scheme is not accurate enough and has a height error, which affects the line of sight judgment of the passageway.

[0006] Therefore, it is necessary to provide a route planning method based on communication link line-of-sight inspection to solve the above-mentioned technical problems. Summary of the Invention

[0007] The main objective of this invention is to provide a route planning method based on communication link visibility check. By using a surface matrix comparison method, the error of communication link visibility check can be reduced, making the reliability of the communication link visibility check higher. Moreover, it can also check the communication link visibility of all waypoints on the route and adjust the positions of waypoints that do not meet the communication link visibility requirements to obtain a route with acceptable communication link visibility.

[0008] This invention achieves the above objective through the following technical solution: a route planning method based on communication link line-of-sight inspection, comprising the following steps:

[0009] Step S1: Design an initial flight path and collect data along the initial flight path at preset intervals. The waypoint, and adjacent to the waypoint The first waypoint, the first Each waypoint is marked as , ,in, , , And s and p are both natural numbers;

[0010] Step S2, Ground station With two adjacent waypoints 、 Connecting the three points in sequence forms a triangular line-of-sight plane (TW). S -W S+1 ), drone at waypoint 、 Mark its position as a flight point when flying between them. The flight point It is the signal transmission point, the ground station. It is a signal receiving point;

[0011] Step S3: Position the line of sight plane (TW) S -W S+1The system expands according to preset rules to form an extended plane, and then performs point sampling within the extended plane to obtain several line-of-sight points. The line of sight The three-dimensional geocentric coordinates are Several of the aforementioned line-of-sight points The three-dimensional geocentric coordinates form a matrix ,in, Indicates the line of sight point latitude, Indicates the line of sight point longitude, Indicates the line of sight point Height;

[0012] Step S4: Obtain the line-of-sight plane (TW) using a three-dimensional elevation map. S -W S+1 Several viewpoints within) The corresponding elevation data, i.e., the line-of-sight point, is obtained. Corresponding ground point The three-dimensional geocentric coordinates of the ground object point The three-dimensional geocentric coordinates are Several of the aforementioned ground points The three-dimensional geocentric coordinates form a matrix ,in, Representing the ground object point Height;

[0013] Step S5: Calculate the Fresnel transmission channel relative to the line-of-sight point. The influence value of height and for the line-of-sight point The height is corrected, and the corrected line of sight point is determined after height correction. The three-dimensional geocentric coordinates are ,and Several correction points The three-dimensional geocentric coordinates form a matrix ,in, The ground station is the first Fresnel diffraction radius. With the flight point Connect to form a straight line The corrected line of sight point With the aforementioned line of sight Connect to form a straight line , The straight line With the straight line The included angle;

[0014] Step S6: Adjust the line of sight for the correction. height With the ground object point height For comparison, several of the aforementioned correction line-of-sight points were examined. height Subtract the corresponding number of ground points height Obtain the height difference matrix ;

[0015] Step S7: Determine the height difference matrix Are all values ​​of the height difference matrix greater than 0? If all values ​​are ≥0, then the waypoint , If the communication link line-of-sight check passes, proceed to step S9; if the height difference matrix... If at least one value is less than 0, then the waypoint is... , If the communication link visibility check fails, proceed to step S8;

[0016] Step S8: Replan waypoints , The location, and follow steps S2~S7 to complete the replanned waypoints. , Communication link visibility check, up to waypoint , The communication link visibility check passed;

[0017] Step S9: Perform communication link visibility checks on other waypoints according to steps S2 to S8 until all waypoints pass the communication link visibility check, thus obtaining a route with good communication link visibility.

[0018] Furthermore, the preset rule for forming the extended plane is: based on the ground stations Starting from point a, with a lateral step size of 'a' and a longitudinal step size of 'b', head towards the waypoint. 、 Extending to one side, n grids extend laterally and m grids extend vertically. The n grids extending laterally and the m grids extending vertically form the extended plane, which is a rectangular plane (TUVE). The line-of-sight plane (TW) S -W S+1 It is located inside the rectangular plane (TUVE).

[0019] Furthermore, point sampling is performed within the rectangular plane (TUVE), and the vertex of each grid is taken as the viewpoint. Several of the aforementioned line-of-sight points The three-dimensional geocentric coordinates form a matrix The three-dimensional geocentric coordinates of the ground station T are: Then the matrix for:

[0020] ;

[0021] Correspondingly, the matrix for:

[0022] ;

[0023] Correspondingly, the matrix for:

[0024] ;

[0025] Correspondingly, the height difference matrix for:

[0026] .

[0027] Furthermore, in step S4, only data existing in the line-of-sight plane (TW) is acquired. S -W S+1 The line of sight within) The corresponding elevation data is in the matrix In, it does not exist in the line-of-sight plane (TW) S -W S+1 The line of sight within) Its corresponding ground point The three-dimensional geocentric coordinates are assigned a constant of 0.

[0028] Furthermore, in step S5, only those existing in the line-of-sight plane (TW) are considered. S -W S+1 The line of sight within) The height is corrected in the matrix. In, it does not exist in the line-of-sight plane (TW) S -W S+1 The line of sight within) The corresponding correction line of sight. The three-dimensional geocentric coordinates are assigned a constant of 0.

[0029] Furthermore, the preset rule for forming the extended plane is: based on the ground stations With the center as the radius, The step size is used to expand and form a fan-shaped plane.

[0030] Furthermore, the preset rule for forming the extended plane is: based on the line-of-sight plane (TW) S -W S+1 The outer center of the circle is the radius. The step size is used to expand and form a circular plane.

[0031] Compared with existing technologies, the beneficial effects of the flight path planning method based on communication link line-of-sight inspection of this invention are as follows: By establishing multiple matrices for the area where waypoints are located, the comparison is changed from point comparison to area matrix comparison, and the altitude is corrected. The line-of-sight calculation speed is faster and more efficient, the number of points covered in the comparison is more uniform, the reliability is higher, the flight path altitude design is more reasonable, the flight range can be shortened, the overall flight time and energy consumption can be saved, and the obstruction area can be given as a whole, which facilitates the subsequent adjustment of waypoint positions. Specifically:

[0032] (1) Ground stations With two adjacent waypoints 、 Connecting the three points in sequence forms a triangular line-of-sight plane (TW). S -W S+1 ), in the line-of-sight plane (TW) S -W S+1 Sampling of several viewpoints within the area First, the influence of the Fresnel transmission channel on altitude is used. line of sight The height is corrected to obtain the corrected line of sight point. This correction method is more accurate and can improve the accuracy of communication link line-of-sight inspection;

[0033] (2) Correct the line of sight point height and ground objects height By comparing the values, the height difference can be obtained. Several correction points height With several ground points height Compare the results to obtain a height difference matrix. Only the height difference matrix If all values ​​are ≥0, then determine the waypoint. The communication link visibility check passed. By using the surface matrix comparison method, the error of the communication link visibility check can be reduced, making the communication link visibility check more reliable.

[0034] (3) This solution can check the line-of-sight communication links of all waypoints on the route and adjust the positions of waypoints with poor line-of-sight communication links in order to obtain a route with good line-of-sight communication links. Attached Figure Description

[0035] Figure 1 This is a structural diagram of an embodiment of the present invention where the extended plane is a rectangular plane (TUVE);

[0036] Figure 2 For embodiments of the present invention at waypoints 、 A schematic diagram of the Fresnel transmission channel during inter-flight. Detailed Implementation

[0037] Please refer to Figures 1-2 This embodiment is a route planning method based on communication link line-of-sight inspection, which includes the following steps:

[0038] Step S1: Design an initial flight path and collect data along the initial flight path at preset intervals. The waypoint, and the The first waypoint, the first The first waypoint, the first Waypoints are marked as , , ,in, , , , And s and p are both natural numbers.

[0039] Several waypoints are collected along the initial route. These waypoints can be collected at equal intervals or at unequal intervals depending on the actual situation. The preset spacing can be set according to the actual situation and is not limited here. p≥2, meaning at least two waypoints are collected along the initial route. If only two waypoints are collected along the initial route, the accuracy of the communication link line-of-sight check is very low, and the probability of false positives is high. To improve the accuracy of the communication link line-of-sight check, multiple waypoints are collected along the initial route. The number of waypoints collected is set based on the actual communication link line-of-sight check accuracy and computational efficiency. Therefore, the number of waypoints collected is not limited here and can be set according to the actual situation.

[0040] Step S2, Ground station With two adjacent waypoints 、 Connecting the three points in sequence forms a triangular line-of-sight plane (TW). S -W S+1 ).

[0041] Drone at waypoint 、 When flying in a straight line, mark its position as the flight point. The signal was transmitted from the drone, i.e., the flight point. It is the signal transmission point, the ground station. It is the signal receiving point, and the three-dimensional geocentric coordinates of the ground station T are: .

[0042] Step S3: Position the line of sight plane (TW) S -W S+1 The system expands according to preset rules to form an extended plane, and then performs point sampling within the extended plane to obtain several line-of-sight points. , line of sight The three-dimensional geocentric coordinates are Several viewpoints The three-dimensional geocentric coordinates form a matrix ,in, Indicates the line of sight point latitude, Indicates the line of sight point longitude, Indicates the line of sight point The height.

[0043] In this embodiment, the preset rules for forming the extended plane are as follows: based on ground stations Starting from point a, with a lateral step size of 'a' and a longitudinal step size of 'b', head towards the waypoint. 、 Extending to one side, n grids extend laterally and m grids extend vertically. The n grids extending laterally and the m grids extending vertically form an extension plane, which is a rectangular plane (TUVE). The rectangular plane (TUVE) is formed by the line-of-sight plane (TW). S -W S+1 The waypoints expand outwards to form a larger plane. 、 They are located on either side of the rectangular plane (TUVE) or inside the rectangular plane (TUVE), i.e., the line-of-sight plane (TW). S -W S+1 It is located inside the rectangular plane (TUVE).

[0044] Point sampling is performed within the rectangular plane (TUVE) to obtain the viewpoint. Take the vertices of each grid, i.e., several viewpoints. The vertices of the grid, and several viewpoints. The three-dimensional geocentric coordinates form a matrix Since the three-dimensional geocentric coordinates of ground station T are Then the matrix for:

[0045] .

[0046] The values ​​of a and b are related to the complexity of the terrain. More complex terrain results in smaller values ​​of a and b, denser grids, and higher computational accuracy. Simpler terrain allows for appropriately larger values ​​of a and b to improve computational efficiency. The values ​​of a and b can be set to be equal or unequal; therefore, their values ​​are set according to the actual situation and are not restricted here. n represents the number of horizontal grids, and m represents the number of vertical grids. The values ​​of n and m are determined based on the line-of-sight plane (TW). S -W S+1 The size of the ) is set, and is not limited here. In this embodiment, point sampling is performed within the rectangular plane (TUVE) to obtain the line-of-sight points. Take the vertices of each grid and several viewpoints. The vertex of the grid can be the center point of the grid or other points. There are no restrictions on the method of sampling points within the rectangular plane (TUVE). You can sample according to the actual situation.

[0047] In this embodiment, the line-of-sight plane (TW) S -W S+1 The plane is expanded according to preset rules to form an extended plane. This extended plane is preferably a regular shape so that the collected line-of-sight points G are uniform, the number of comparison points is more evenly covered, the reliability is higher, and the flight path altitude design is more reasonable.

[0048] In other embodiments, the preset rules for forming the extended plane can also take other forms, for example, based on ground stations. With the center as the radius, Using a step size, expand to form a fan-shaped plane, and then perform point sampling within the fan-shaped plane to obtain several viewpoints. ; or using the line-of-sight plane (TW) S -W S+1 The outer center of the circle is the radius. Using a step size, expand to form a circular plane, and then perform point sampling within the circular plane to obtain several viewpoints. Therefore, different shapes of extended planes can be formed according to various other preset rules.

[0049] Therefore, the preset rules, the shape of the extended plane, and the viewpoint The sampling method is not restricted here and can be set according to the actual situation.

[0050] Step S4: Obtain the line-of-sight plane (TW) from the 3D elevation map. S -W S+1 Several viewpoints within) The corresponding elevation data, i.e., the line-of-sight point. Corresponding ground point The three-dimensional geocentric coordinates, due to the ground object points Located at the point of view Directly above or directly below, therefore ground objects The three-dimensional geocentric coordinates are ,in, Representing ground point The height of several ground points The three-dimensional geocentric coordinates form a matrix ,matrix for:

[0051] .

[0052] Obtain the line-of-sight plane (TW) from a 3D elevation map. S -W S+1 Several viewpoints within) The corresponding elevation data is based on existing technology, and any methods found in existing technologies will suffice; no restrictions are imposed here. To save computational efficiency, only data existing in the line-of-sight plane (TW) will be acquired. S -W S+1 The line of sight within) The corresponding elevation data is not acquired if it exists within the extended plane but not within the line-of-sight plane (TW). S -W S+1 The line of sight within) The corresponding elevation data, therefore, in the matrix In the middle, it does not exist in the line-of-sight plane (TW) S -W S+1 The line of sight within) Its corresponding ground point The three-dimensional geocentric coordinates can be assigned a constant of 0.

[0053] Step S5: Calculate the line-of-sight point of the Fresnel transmission channel. The influence value of height, and its effect on the line of sight. The height is corrected, and the corrected line of sight point is determined after height correction. The three-dimensional geocentric coordinates are The impact of Fresnel transmission channels on altitude ,Right now ,in, For the first Fresnel diffraction radius, the ground station Flight point Straight lines connected together form a straight line Correcting the line of sight With line of sight Connect to form a straight line , It is a straight line With a straight line The included angle; several correction line-of-sight points The three-dimensional geocentric coordinates form a matrix ,matrix for:

[0054] .

[0055] To save computational efficiency, only those existing in the line-of-sight plane (TW) are considered. S -W S+1 The line of sight within) The height is corrected for those existing in the extended plane but not in the line-of-sight plane (TW). S -W S+1 The line of sight within) The height is not corrected, therefore, in the matrix In the middle, it does not exist in the line-of-sight plane (TW) S -W S+1 The line of sight within) The corresponding correction line of sight. The three-dimensional geocentric coordinates can be assigned a constant of 0.

[0056] The impact of Fresnel transmission channels on altitude The specific calculation process is as follows: Since the Fresnel diffraction region is an ellipsoid, only the lower half perpendicular to the ground needs to be analyzed; other directions will not cause obstruction, thus not affecting the line-of-sight of the communication link. For example... Figure 2 As shown, ground stations Flight point Ground stations are located at the two foci of the ellipsoid. Flight point Straight lines connected together form a straight line , This represents a line segment. Length, line of sight Located on a straight line Above, correct the line of sight. Located at the point of view Directly below and located on the surface of the ellipsoid, by the correction line of sight point Towards a straight line Draw a perpendicular line to obtain a perpendicular line. The foot of the perpendicular is , Represents a perpendicular line segment In this embodiment, the length of , The first Fresnel diffraction radius Correcting the line of sight With line of sight Connect to form a straight line ,straight line Perpendicular to the ground, straight line With a straight line The included angle between them is , Represents line segment Length, That is, the line of sight. With correction of line of sight The height difference between them, i.e. Because of triangle It is a right triangle, therefore, .

[0057] According to the Fresnel diffraction principle, we can obtain:

[0058] (1)

[0059] in, The wavelength of the communication signal. For line segments Length, For line segments Length;

[0060] in addition, , Since all triangles are right triangles, then:

[0061] (2)

[0062] (3)

[0063] (4)

[0064] in, For line segments Length, For line segments Length;

[0065] From the formulas (1) to (4) above, we can derive:

[0066] ;

[0067] That is, the first Fresnel diffraction radius ;

[0068] therefore, .

[0069] Compared to existing technologies, the above correction method is more accurate and can improve the accuracy of communication link line-of-sight inspection.

[0070] Step S6: Correct the line of sight point height and ground objects height Compare and use the corrected line of sight point. Three-dimensional geocentric coordinates Correspondingly subtract ground object points Three-dimensional geocentric coordinates Obtain the difference coordinates Since only height coordinates affect the line-of-sight of the communication link, remove... , Coordinate values, retain only the height difference. Several correction points height With several ground points height By comparing the results, a height difference matrix is ​​obtained. Height difference matrix Represented as:

[0071] .

[0072] Step S7: Determine the height difference matrix Are all values ​​greater than 0 in the height difference matrix? If all values ​​are ≥0, then the waypoint , If the communication link line-of-sight check passes, proceed to step S9; if the height difference matrix... If at least one value is less than 0, then the waypoint is... , If the communication link visibility check fails, proceed to step S8.

[0073] Step S8: Replan waypoints , The location, and follow steps S2~S7 to complete the replanned waypoints. , Communication link visibility check, up to waypoint , The communication link visibility check passed.

[0074] Specifically, due to the height difference matrix If at least one value is less than 0, it indicates that the waypoint's altitude is too low. Therefore, waypoints need to be replanned. , When the location is determined, the waypoint should be increased first. , The altitude, as for waypoints , Whether the latitude and longitude need to be adjusted depends on the actual terrain.

[0075] Step S9: Perform communication link visibility checks on other waypoints according to steps S2 to S8 until all waypoints pass the communication link visibility check, thus obtaining a route with good communication link visibility.

[0076] Specifically, for example, waypoints , If the communication link line-of-sight check passes, the next step will be via ground station. With two adjacent waypoints 、 Connecting the three points in sequence forms a triangular line-of-sight plane (TW). S+1 -W S+2 Repeat steps S2 to S8, for The communication link is checked for line of sight. If the communication link line-of-sight test passes, the next step will be via ground station. With two adjacent waypoints 、 Connecting the three points in sequence forms a triangular line-of-sight plane (TW). S+2 -W S+3 Repeat steps S2 to S8, for The communication link is checked for line of sight. If the communication link visibility check passes, then the above process is repeated to check each waypoint until the communication link visibility check of all waypoints passes, thus obtaining a route with good communication link visibility.

[0077] ground stations With two adjacent waypoints 、 Connecting the three points in sequence forms a triangular line-of-sight plane (TW). S -W S+1 ), in the line-of-sight plane (TW) S -W S+1 Sampling of several viewpoints within the area First, the influence of the Fresnel transmission channel on altitude is used. line of sight The height is corrected to obtain the corrected line of sight point. This correction method offers higher accuracy and can improve the precision of communication link line-of-sight checks; then, the correction line-of-sight points are... height and ground objects height Compare the height differences Only the height difference matrix If all values ​​are ≥0, then determine the waypoint. 、 The communication link visibility check is passed. The above-mentioned method of surface matrix comparison is more accurate and can reduce the error of the communication link visibility check, thus increasing the reliability of the communication link visibility check. Moreover, this solution can check the communication link visibility of all waypoints on the route and adjust the positions of waypoints that fail the communication link visibility check to obtain a route with compliant communication link visibility.

[0078] The above descriptions are merely some embodiments of the present invention. Those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A method for flight planning based on communication link visibility check, characterized in that: It includes the following steps: Step S1, design an initial route to collect a plurality of waypoints on the initial route at a preset interval, and mark adjacent first and second waypoints as and respectively, wherein s and p are natural numbers. ​​​​​​​​ Step S2, Ground station With two adjacent waypoints 、 Connecting the three points in sequence forms a triangular line-of-sight plane (TW). S -W S+1 ), drone at waypoint 、 Mark its position as a flight point when flying between them. The flight point It is the signal transmission point, the ground station. It is a signal receiving point; Step S3: Position the line of sight plane (TW) S -W S+1 The system expands according to preset rules to form an extended plane, and then performs point sampling within the extended plane to obtain several line-of-sight points. The line of sight The three-dimensional geocentric coordinates are Several of the aforementioned line-of-sight points The three-dimensional geocentric coordinates form a matrix ,in, Indicates the line of sight point latitude, Indicates the line of sight point longitude, Indicates the line of sight point Height; Step S4: Obtain the line-of-sight plane (TW) using a three-dimensional elevation map. S -W S+1 Several viewpoints within) The corresponding elevation data, i.e., the line-of-sight point, is obtained. Corresponding ground point The three-dimensional geocentric coordinates of the ground object point The three-dimensional geocentric coordinates are Several of the aforementioned ground points The three-dimensional geocentric coordinates form a matrix ,in, Representing the ground object point Height; Step S5: Calculate the Fresnel transmission channel relative to the line-of-sight point. The influence value of height and for the line-of-sight point The height is corrected, and the corrected line of sight point is determined after height correction. The three-dimensional geocentric coordinates are ,and Several correction points The three-dimensional geocentric coordinates form a matrix ,in, The ground station is the first Fresnel diffraction radius. With the flight point Connect to form a straight line The corrected line of sight point With the aforementioned line of sight Connect to form a straight line , The straight line With the straight line The included angle; Step S6: Adjust the line of sight for the correction. height With the ground object point height For comparison, several of the aforementioned correction line-of-sight points were examined. height Subtract the corresponding number of ground points height Obtain the height difference matrix ; Step S7: Determine the height difference matrix Are all values ​​of the height difference matrix greater than 0? If all values ​​are ≥0, then the waypoint , If the communication link line-of-sight check passes, proceed to step S9; if the height difference matrix... If at least one value is less than 0, then the waypoint is... , If the communication link visibility check fails, proceed to step S8; Step S8: Replan waypoints , The location, and follow steps S2~S7 to complete the replanned waypoints. , Communication link visibility check, up to waypoint , The communication link visibility check passed; Step S9: Perform communication link visibility checks on other waypoints according to steps S2 to S8 until all waypoints pass the communication link visibility check, thus obtaining a route with good communication link visibility.

2. The route planning method based on communication link line-of-sight inspection as described in claim 1, characterized in that: The preset rule for forming the extended plane is: based on the ground stations Starting from point a, with a lateral step size of 'a' and a longitudinal step size of 'b', head towards the waypoint. 、 Extending to one side, n grids extend laterally and m grids extend vertically. The n grids extending laterally and the m grids extending vertically form the extended plane, which is a rectangular plane (TUVE). The line-of-sight plane (TW) S -W S+1 It is located inside the rectangular plane (TUVE).

3. The route planning method based on communication link line-of-sight inspection as described in claim 2, characterized in that: Point sampling is performed within the rectangular plane (TUVE), and the vertex of each grid is taken as the viewpoint. Several of the aforementioned line-of-sight points The three-dimensional geocentric coordinates form a matrix The three-dimensional geocentric coordinates of the ground station T are: Then the matrix for: ； Correspondingly, the matrix for: ； Correspondingly, the matrix for: ； Correspondingly, the height difference matrix for: 。 4. The route planning method based on communication link line-of-sight inspection as described in claim 3, characterized in that: In step S4, only data existing in the line-of-sight plane (TW) is acquired. S -W S+1 The line of sight within) The corresponding elevation data is in the matrix In, it does not exist in the line-of-sight plane (TW) S -W S+1 The line of sight within) Its corresponding ground point The three-dimensional geocentric coordinates are assigned a constant of 0.

5. The route planning method based on communication link line-of-sight inspection as described in claim 3, characterized in that: In step S5, only those existing in the line-of-sight plane (TW) are considered. S -W S+1 The line of sight within) The height is corrected in the matrix. In, it does not exist in the line-of-sight plane (TW) S -W S+1 The line of sight within) The corresponding correction line of sight. The three-dimensional geocentric coordinates are assigned a constant of 0.

6. The route planning method based on communication link line-of-sight inspection as described in claim 1, characterized in that: The preset rule for forming the extended plane is: based on the ground stations With the center as the radius, The step size is used to expand and form a fan-shaped plane.

7. The route planning method based on communication link line-of-sight inspection as described in claim 1, characterized in that: The preset rule for forming the extended plane is: based on the line-of-sight plane (TW) S -W S+1 The outer center of the circle is the radius. The step size is used to expand and form a circular plane.

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