A method and device for adjusting the height of a UAV flight path, and an electronic device, storage medium and program product

Abstract

The application relates to a method and device for adjusting the height of a UAV route, and an electronic device, a storage medium and a program product, and relates to the field of UAVs, and solves the technical problem that unreasonable flight height values in the existing UAV route cause flight risks. The method for adjusting the height of the UAV route comprises the following steps: S100, obtaining the elevation values of one or more interpolation points on a flight section in a UAV route according to the longitude and latitude values of two endpoints of the flight section; S200, determining the occlusion height values of the interpolation points according to the initial height values of the two endpoints and the elevation values of the interpolation points; S300, selecting the maximum occlusion height value from the occlusion height values of the one or more interpolation points; and S400, updating the initial height values of the two endpoints according to the maximum occlusion height value.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicles (UAVs), and more particularly to a method and apparatus for adjusting the flight path altitude of a UAV, as well as an electronic device, storage medium, and program product. Background Technology

[0002] Unmanned aerial vehicle (UAV) flight path planning refers to determining an optimal flight path based on the target characteristics of a mission under certain constraints. Currently, the most common method is to manually plan the UAV mission flight path on a two-dimensional digital map within the UAV ground control station software. This method requires manually setting the latitude and longitude coordinates of multiple waypoints, which are then automatically connected by the UAV ground control station software to create the UAV flight path. The planned path is then uploaded to the UAV via a data link, and the UAV begins flying according to the planned route.

[0003] Flight paths drawn using current route planning methods have automatically generated flight altitude values, typically a fixed value (e.g., 3000 meters). Manually drawn routes do not consider flight altitude constraints. The flight altitude of a UAV is crucial for safe flight. An appropriate altitude helps the UAV avoid collisions with other aircraft, evade obstacles, maintain adequate visibility and communication range, and ensure stability and efficiency during mission execution. However, limited by operator skill or facing complex, dynamic, multi-constrained, and highly uncertain reconnaissance environments, manually drawn routes often fail to adequately consider ground elevation and obstacles. Some segments may be too low, causing the route to pass over ground objects such as mountains, forests, and tall buildings, creating flight hazards. Furthermore, manually adjusting the altitude of flight paths to a uniformly high value reduces the UAV's flexibility, fails to meet diverse mission requirements, and wastes resources.

[0004] Some UAV ground control station software also supports automatic flight path planning using built-in algorithms. However, these algorithms vary in quality, and in complex and dynamic environments, automatically planned flight paths may exhibit excessively low altitudes. Furthermore, these algorithms cannot accurately and efficiently generate UAV flight paths with altitudes within a reasonable range using terrain data. Therefore, an efficient and reliable flight path detection technology is urgently needed to address these concerns. Summary of the Invention

[0005] Based on the above analysis, the embodiments of the present invention aim to provide a method, apparatus, electronic device, storage medium, and program product for adjusting the flight path altitude of a drone, in order to solve the technical problem of flight danger caused by unreasonable flight altitude values ​​in existing drone flight paths.

[0006] In a first aspect, embodiments of the present invention provide a method for adjusting the flight path altitude of a drone, comprising the following steps:

[0007] Step S100: Based on the latitude and longitude values ​​of the two endpoints of the flight segment in the UAV flight path, obtain the elevation values ​​of one or more interpolation points on the flight segment;

[0008] Step S200: Determine the occlusion height value of the interpolation point based on the initial height values ​​of the two endpoints and the elevation value of the interpolation point;

[0009] Step S300: Select the maximum occlusion height value from one or more of the occlusion height values ​​of the interpolation points; and

[0010] Step S400: Update the initial height values ​​of the two endpoints according to the maximum occlusion height value.

[0011] Based on a further improvement to the above adjustment method, before performing step S100, the following steps are also included:

[0012] Perform line-of-sight analysis on segments of the drone's flight path;

[0013] In response to the existence of a non-line-of-sight flight segment, proceed to step S100.

[0014] Based on a further improvement of the above adjustment method, the method for selecting the interpolation point is as follows:

[0015] Points are interpolated on the said route according to the resolution of the elevation map.

[0016] Based on a further improvement of the above adjustment method, step S200 includes:

[0017] The initial height value of the interpolation point is determined based on the initial height values ​​and latitude and longitude values ​​of the two endpoints;

[0018] The occlusion height value of the interpolation point is obtained by subtracting its initial height value from its elevation value.

[0019] Based on a further improvement to the above adjustment method, the initial height value of the interpolation point is determined according to the initial height values ​​and latitude and longitude values ​​of the two endpoints, including:

[0020] The initial height H of the interpolation point is calculated using the following formula. B :

[0021] H B =H S +(H T –H S )*(L SB / LST )

[0022] Among them, H S H T These are the initial height values ​​of the starting point S and the target point T, respectively, L. SB L ST These are the planar distances between the starting point S and the interpolation point B and the target point T, respectively.

[0023] Based on a further improvement of the above adjustment method, step S400 includes:

[0024] The maximum occlusion height value is increased to the initial height value of each of the two endpoints.

[0025] Secondly, embodiments of the present invention provide a device for adjusting the flight path altitude of a UAV, comprising:

[0026] The acquisition module is configured to acquire the elevation values ​​of one or more interpolation points on the flight segment based on the latitude and longitude values ​​of the two endpoints of the flight segment in the UAV flight path;

[0027] The determining module is configured to determine the occlusion height value of the interpolation point based on the initial height values ​​of the two endpoints and the elevation value of the interpolation point;

[0028] The selection module is configured to select the maximum occlusion height value from the occlusion height values ​​of one or more of the interpolation points; and

[0029] The update module is configured to update the initial height values ​​of the two endpoints based on the maximum occlusion height value.

[0030] Thirdly, embodiments of the present invention provide an electronic device, including:

[0031] At least one processor; and

[0032] A memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the method for adjusting the flight path altitude of a UAV as described in any of the first aspects of the present invention.

[0033] Fourthly, embodiments of the present invention provide a non-transitory computer-readable storage medium storing computer instructions, the computer instructions being used to cause the computer to execute the safety detection method for planning flight routes of unmanned aerial vehicles as described in any of the first aspects of the present invention.

[0034] Fifthly, embodiments of the present invention provide a computer program product, including program code instructions, wherein when the program product is executed by a computer, the program code instructions cause the computer to execute the safety detection method for planning flight routes of unmanned aerial vehicles as described in any of the first aspects of the present invention.

[0035] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0036] 1. The present invention provides an efficient and reliable flight path altitude detection technology, which can accurately detect unreasonable flight altitude values ​​in the planned flight path of UAVs and automatically generate new flight paths, thereby improving the safety of UAV flight.

[0037] 2. The flight path altitude detection technology provided by the present invention can cope with complex and dynamic environments and has good robustness.

[0038] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0039] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0040] Figure 1 A flowchart illustrating a method for adjusting the flight path altitude of a drone according to an embodiment of the present invention is shown.

[0041] Figure 2 A conceptual schematic diagram of a drone flight path is shown in an embodiment of the present invention.

[0042] Figure 3 A schematic diagram of interpolation points on a flight segment according to an embodiment of the present invention is shown.

[0043] Figure 4 An example of calculating the occlusion height value of the interpolation point is shown.

[0044] Figure 5 A schematic diagram illustrating the principle of view-through analysis according to an embodiment of the present invention is shown.

[0045] Figure 6 An exemplary block diagram of a drone flight path altitude adjustment device according to an embodiment of the present invention is shown.

[0046] Figure 7A schematic block diagram of an example electronic device 700 that can be used to implement embodiments of the present disclosure is shown. Detailed Implementation

[0047] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0048] Figure 1 A flowchart illustrating a method for adjusting the flight path altitude of a drone according to an embodiment of the present invention is shown. Figure 1 As shown, the method for adjusting the flight path altitude of this drone includes the following steps:

[0049] Step S100: Based on the latitude and longitude values ​​of the two endpoints of the flight segment in the UAV flight path, obtain the elevation values ​​of one or more interpolation points on the flight segment.

[0050] In this embodiment, the UAV flight path can be a manually drawn path. In this embodiment, manually drawn path data can be obtained by importing a path file. This path data includes the latitude, longitude, and altitude data of each waypoint along the path. Figure 2 A conceptual schematic diagram of a drone flight path according to an embodiment of the present invention is shown. Figure 2 As shown in the left figure, four waypoints can be marked on the two-dimensional map first. Figure 2 The waypoints (A, B, C, D) are then manually connected along the flight direction to form a flight path. The diagram on the right illustrates this path, which consists of three segments interconnected, each containing two waypoints. For example, the first segment includes waypoints A and B. The altitude of each waypoint along the UAV flight path is typically a fixed value generated by the system (e.g., 3000 meters). It should be noted that, unless otherwise specified, the terms "waypoint" and "endpoint of a segment" have the same meaning in this document.

[0051] In this embodiment, the UAV flight path can also be automatically planned using the automatic flight path planning algorithm built into the UAV ground station software. The UAV ground station software utilizes this algorithm to automatically generate a UAV flight path based on terrain features. The automatically planned flight path includes the latitude, longitude, and altitude data of each waypoint along the path.

[0052] In this embodiment, the elevation values ​​of the area traversed by the UAV flight path can be obtained through an imported Digital Elevation Model (DEM). A DEM is a data model used to represent the elevation of the Earth's surface. It is stored in digital form, typically in raster or grid format, with each cell containing an elevation value representing the elevation of that location on the ground. Locations on the ground can be represented by latitude and longitude values. In this embodiment, the elevation value of a waypoint can be obtained by indexing it in the imported DEM based on its latitude and longitude values. It should be noted that DEM data is also called an elevation map; in this document, the terms DEM and elevation map are used interchangeably.

[0053] In this embodiment, the interpolation point of the flight segment can be a point in the flight segment that is obscured by terrain. Figure 3 A schematic diagram of interpolation points for flight segments according to an embodiment of the present invention is shown. For example... Figure 3 As shown, S and T are the two endpoints of the two flight segments [S,T], with elevation value G at waypoint S and elevation value G1 at waypoint T. Flight segment [S,T] includes a region [B1,B2] obscured by terrain. Figure 3 The points are represented by dashed lines. The interpolation points for flight segment [S,T] can be one or more points on flight segment [B1,B2].

[0054] In some embodiments, the method for selecting interpolation points for a flight segment can be to interpolate points on the flight segment according to the resolution of the elevation map. To ensure the absolute safety of the flight route altitude, in this embodiment, points can be interpolated on the flight segment according to the resolution of the DEM terrain data, and each interpolation point is an interpolation point for the flight segment. For example, in Figure 3 In the case where the length of flight segment [S,T] is L ST The resolution of the DEM terrain data at flight segment [S,T] is T. res Then L can be calculated. ST / T res Rounded down, this number is denoted as Count. Count represents the number of interpolation points to be inserted in the segment [S,T]. The distance between the first interpolation point and waypoint S is L. ST / Count, the distance between the second interpolation point and waypoint S is 2L. ST / Count, the distance between the third interpolation point and waypoint S is 3L. ST / Count, and so on.

[0055] In this embodiment, the elevation value of the interpolation point can be obtained by indexing the imported DEM based on the latitude and longitude values ​​of the interpolation point on the flight segment.

[0056] Step S200: Determine the occlusion height value of the interpolation point based on the initial height values ​​of the two endpoints and the elevation value of the interpolation point.

[0057] The initial altitude value of a manually drawn drone flight path refers to the altitude generated by the system by default, usually a fixed value (e.g., 3000 meters). The initial altitude values ​​of each waypoint on the drone flight path are also fixed values. The initial altitude value of an automatically generated drone flight path refers to the altitude value generated by the system based on terrain characteristics.

[0058] In this embodiment, the initial altitude value of the interpolation point can be determined based on the initial altitude and latitude / longitude values ​​of the two endpoints of the flight segment. Then, the occlusion altitude value of the interpolation point can be obtained by subtracting the initial altitude value of the interpolation point from its elevation value.

[0059] Figure 4 An example of calculating the occlusion height value of the interpolation point is shown below. Figure 4 Step S200 will be explained. For example... Figure 4 As shown, let S and T be two adjacent waypoints on the route, where S is the starting point and T is the ending point. Let the initial altitude of the interpolation point B, which is obscured by terrain, be H. B The elevation value of interpolation point B is H. B1 From the vector calculation formula, we can obtain:

[0060] H B =H S +(H T –H S )*(L SB / L ST );

[0061] Among them, H S H T These are the initial height values ​​of the starting point S and the ending point T, respectively, L. SB L ST These are the planar distances between the starting point S, the interpolation point B, and the ending point T, respectively. SB L can be directly calculated from the latitude and longitude coordinates of the starting point S and the interpolation point B. ST H can be directly calculated from the latitude and longitude coordinates of the starting point S and the ending point T. B1 It can be read directly from the DEM. The occlusion height D of interpolation point B. BB1 It is calculated using the following formula:

[0062] D BB1＝ H B1 –H B .

[0063] Step S300: Select the maximum occlusion height value from one or more of the occlusion height values ​​of the interpolation points.

[0064] Step S400: Update the initial height values ​​of the two endpoints according to the maximum occlusion height value.

[0065] exist Figure 4 In the example, the occlusion height values ​​of all interpolation points in flight segment [S,T] can be compared, and the maximum value is retained, which is the maximum occlusion height value of flight segment [S,T], denoted as D. MAX .

[0066] In this embodiment, the maximum obstruction height value of the flight segment can be used to update the initial altitude values ​​of the two endpoints of the flight segment. In some embodiments, the maximum obstruction height value of the flight segment can be increased to the initial altitude values ​​of the two endpoints of the flight segment. Figure 4 In the example, the maximum obstruction height of flight segment [S,T] is the obstruction height value D at point B. BB1 Therefore, the occlusion height value D of point B can be determined. BB1 Add to the starting point S to obtain a new starting point S1, and change the occlusion height value D of point B. BB1 Adding to the destination T results in a new destination T1, and the segment [S1,T1] is the updated segment.

[0067] In some embodiments, before performing step S100, Figure 1 The method also includes the following steps: performing line-of-sight analysis on segments of the UAV flight path; and proceeding to step S100 in response to the existence of non-line-of-sight segments. Figure 5 A schematic diagram illustrating the principle of view-through analysis according to an embodiment of the present invention is shown. Figure 5 As shown, point O is the observation point, points B and C are target points, OG is the observation height of point O above the ground, and BG1 and CG1 are the observation heights of points B and C above the ground, respectively. Figure 5 As can be seen, there is no terrain obstruction between OCs, and they are line-of-sight. However, there is terrain obstruction between OBs. Point O can see point B1 at its furthest point. Although segment B2B is higher than the terrain, it is obstructed by B1B2, making it inaccessible to OBs. In this embodiment, a grid-based line-of-sight algorithm, the R3 algorithm, or the PDERL algorithm can be used to perform line-of-sight analysis on segments in the UAV flight path.

[0068] Figure 6 An exemplary block diagram of a drone flight path altitude adjustment device according to an embodiment of the present invention is shown. Figure 6As shown, the drone flight path altitude adjustment device 600 includes: an acquisition module 601 configured to acquire the elevation values ​​of one or more interpolation points on the flight path segment based on the latitude and longitude values ​​of two endpoints of the segment; a determination module 602 configured to determine the occlusion height value of the interpolation point based on the initial altitude values ​​of the two endpoints and the elevation value of the interpolation point; a selection module 603 configured to select the maximum occlusion height value from the occlusion height values ​​of one or more interpolation points; and an update module 604 configured to update the initial altitude values ​​of the two endpoints based on the maximum occlusion height value.

[0069] It should be understood that Figure 6 The various modules of the device 600 shown can be connected to the reference. Figure 1 The steps in the described method correspond accordingly. Therefore, the operations, features, and advantages described above for the method also apply to apparatus 600 and its included modules. For the sake of brevity, some operations, features, and advantages will not be repeated here.

[0070] Figure 7 A schematic block diagram of an example electronic device 700 that can be used to implement embodiments of the present disclosure is shown. See also Figure 7 The present invention describes a structural block diagram of an electronic device 700 that can serve as a server or client of the present disclosure, which is an example of a hardware device that can be applied to various aspects of the present disclosure. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present disclosure described and / or claimed herein. Figure 7As shown, the electronic device 700 includes a computing unit 701, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 702 or a computer program loaded from a storage unit 708 into a random access memory (RAM) 703. The RAM 703 may also store various programs and data required for the operation of the device 700. The computing unit 701, ROM 702, and RAM 703 are interconnected via a bus 704. An input / output (I / O) interface 705 is also connected to the bus 704. Multiple components in the device 700 are connected to the I / O interface 705, including: an input unit 706, such as a keyboard, mouse, etc.; an output unit 707, such as various types of displays, speakers, etc.; a storage unit 708, such as a disk, optical disk, etc.; and a communication unit 709, such as a network card, modem, wireless transceiver, etc. The communication unit 709 allows the device 700 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0071] The computing unit 701 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 701 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The computing unit 701 performs the various methods and processes described above, such as the method for adjusting the flight path altitude of a drone. For example, in some embodiments, the method for adjusting the flight path altitude of a drone can be implemented as a computer software program, which is tangibly contained in a machine-readable medium, such as storage unit 708. In some embodiments, part or all of the computer program can be loaded and / or installed on device 700 via ROM 702 and / or communication unit 709. When the computer program is loaded into RAM 703 and executed by the computing unit 701, one or more steps of the gift package recommendation method described above can be performed. Alternatively, in other embodiments, the computing unit 701 can be configured to perform the method for adjusting the flight path altitude of a drone by any other suitable means (e.g., by means of firmware).

[0072] This invention provides a non-transitory computer-readable storage medium storing computer instructions for instructing the computer to perform any of the above-described methods for adjusting the flight path altitude of a drone. In this document, one or more computer-readable non-transitory storage media may include one or more semiconductor-based or other integrated circuits (ICs) (e.g., field-programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs)), hard disk drives (HDDs), hybrid hard disk drives (HHDs), optical disks, optical disk drives (ODDs), magneto-optical disks, magneto-optical disk drives, floppy disks, floppy disk drives (FDDs), magnetic tape, solid-state drives (SSDs), RAM drives, and any other suitable computer-readable non-transitory storage media. The computer-readable non-transitory storage medium may be volatile, non-volatile, or a combination of volatile and non-volatile.

[0073] This invention provides a computer program product, including program code instructions. When the program product is executed by a computer, the program code instructions cause the computer to execute any of the above-described methods for adjusting the flight path altitude of a UAV.

[0074] Compared with the prior art, the embodiments of the present invention can achieve at least one of the following beneficial effects:

[0075] 1. The present invention provides an efficient and reliable flight path altitude detection technology, which can accurately detect unreasonable flight altitude values ​​in the planned flight path of UAVs and automatically generate new flight paths, thereby improving the safety of UAV flight.

[0076] 2. The flight path altitude detection technology provided by the present invention can cope with complex and dynamic environments and has good robustness.

[0077] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for adjusting the flight path altitude of a drone, characterized in that, Includes the following steps: Step S100: Based on the latitude and longitude values ​​of the two endpoints of the flight segment in the UAV flight path, obtain the elevation values ​​of one or more interpolation points on the flight segment, wherein the interpolation points are points in the flight segment that are obscured by terrain, and the flight segment in the UAV flight path that is obscured by terrain is a flight segment automatically obtained through line-of-sight analysis. Step S200: Determine the occlusion height value of the interpolation point based on the initial height values ​​of the two endpoints and the elevation value of the interpolation point; Step S300: Select the maximum occlusion height value from one or more of the occlusion height values ​​of the interpolation points; as well as Step S400: Update the initial height values ​​of the two endpoints according to the maximum occlusion height value; Step S400 includes: The maximum occlusion height value is increased to the initial height value of each of the two endpoints; Step S200 includes: The initial height value of the interpolation point is determined based on the initial height values ​​and latitude and longitude values ​​of the two endpoints; The occlusion height value of the interpolation point is obtained by subtracting the initial height value of the interpolation point from its elevation value. The elevation value of the interpolation point is directly obtained from the elevation map. The initial altitude value of the interpolation point is determined based on the initial altitude and latitude / longitude values ​​of the two endpoints, including: The initial height H of the interpolation point is calculated using the following formula. B : H B = H S + (H T -H S ) (L SB / L ST ) Among them, H S H T These are the initial height values ​​of the starting point S and the target point T, respectively, L. SB L ST These are the planar distances between the starting point S and the interpolation point B and the target point T, respectively.

2. The adjustment method according to claim 1, characterized in that, Before performing step S100, the following steps are also included: Perform line-of-sight analysis on segments of the drone's flight path; In response to the existence of a non-line-of-sight flight segment, proceed to step S100.

3. The adjustment method according to claim 1, characterized in that, The method for selecting the interpolation points is as follows: Points are interpolated on the said route according to the resolution of the elevation map.

4. A device for adjusting the flight path altitude of a drone, characterized in that, include: The acquisition module is configured to acquire the elevation values ​​of one or more interpolation points on the flight segment based on the latitude and longitude values ​​of the two endpoints of the flight segment in the UAV flight path, wherein the interpolation points are points in the flight segment that are obscured by terrain, and the flight segment in the UAV flight path that is obscured by terrain is a flight segment automatically acquired through line-of-sight analysis. The determining module is configured to determine the occlusion height value of the interpolation point based on the initial height values ​​of the two endpoints and the elevation value of the interpolation point; The selection module is configured to select the maximum occlusion height value from the occlusion height values ​​of one or more of the interpolation points; as well as The update module is configured to update the initial height values ​​of the two endpoints based on the maximum occlusion height value; The update module is further configured to increase the maximum occlusion height value to the initial height value of the two endpoints respectively; The determining module is further configured as follows: The initial height value of the interpolation point is determined based on the initial height values ​​and latitude and longitude values ​​of the two endpoints; The occlusion height value of the interpolation point is obtained by subtracting the initial height value of the interpolation point from its elevation value. The elevation value of the interpolation point is directly obtained from the elevation map. The initial altitude value of the interpolation point is determined based on the initial altitude and latitude / longitude values ​​of the two endpoints, including: The initial height H of the interpolation point is calculated using the following formula. B : H B = H S + (H T -H S ) (L SB / L ST ) Among them, H S H T These are the initial height values ​​of the starting point S and the target point T, respectively, L. SB L ST These are the planar distances between the starting point S and the interpolation point B and the target point T, respectively.

5. An electronic device, comprising: At least one processor; A memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform claim 1. The method for adjusting the flight path altitude of the UAV as described in any one of the 3.

6. A non-transitory computer-readable storage medium storing computer instructions for causing the computer to perform the functions of claim 1. The method for adjusting the flight path altitude of the UAV as described in any one of the 3.

7. A computer program product comprising program code instructions that, when executed by a computer, cause the computer to perform the method of at least one of claims 1 to 3.

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