Civil aircraft star air-ground communication link construction method based on large satellite constellation

Abstract

The invention discloses a civil aircraft star air-ground communication link construction method based on a large-scale satellite constellation, and the method comprises the following steps: constructing large-scale satellite constellation star air-ground communication network nodes and an edge connection model, the nodes including satellite nodes, civil aircraft nodes and ground station nodes, the edge connection model is constructed based on a spatial position relationship among satellite nodes, civil aircraft nodes and ground station nodes and communication constraint conditions; on the basis of a large constellation satellite orbit forecasting algorithm, predicting the orbit position of a satellite node in a preset time; dynamically constructing a starry sky-ground communication link based on the orbit position of the satellite node and the communication constraint condition of the starry sky-ground; and based on an inter-satellite routing screening algorithm, screening out an optimal communication link from the constructed star-sky-ground communication links. The method can lay a theoretical reference for civil aircraft star air-ground communication link construction under the support of a large-scale constellation communication network.

Description

Technical Field

[0001] The present invention belongs to the technical field of the construction of space-air-ground communication networks, and particularly relates to a method for constructing a space-air-ground communication link for civil aircraft based on a large satellite constellation. Background Art

[0002] With the rapid deployment of large low-earth orbit constellations represented by Starlink and OneWeb, the application of satellite-based Internet in the future communication field is an irresistible trend. In recent years, new satellite networks have been widely commercialized and become an indispensable important network infrastructure for providing global communication and broadband Internet. At the same time, the growing safety requirements of the civil aviation industry have put forward higher requirements for the network in terms of global coverage, reliable transmission, and efficient computing. For example, for civil aircraft, synchronizing the data recorded in the black box to a cloud server can greatly speed up the process of accident analysis and investigation after an air crash. Subsequently, various parameters of the aircraft can be obtained directly by querying the cloud server during the follow-up investigation.

[0003] Different from traditional ground communication networks which are mostly based on ground nodes, the technology of space-air-ground communication networks is not yet mature and is still in the stage of research, testing, and verification globally. Existing research on large constellation networks has the problem of insufficient consideration of high dynamicity. Based on this, there is an urgent need to propose a method for constructing a space-air-ground communication link for civil aircraft based on a large satellite constellation. Summary of the Invention

[0004] To solve the above technical problems, the present invention proposes a method for constructing a space-air-ground communication link for civil aircraft based on a large satellite constellation to solve the problems existing in the above prior art.

[0005] To achieve the above object, the present invention provides a method for constructing a space-air-ground communication link for civil aircraft based on a large satellite constellation, including the following steps:

[0006] Construct a space-air-ground communication network node and edge model for a large constellation, where the nodes include satellite nodes, civil aircraft nodes, and ground station nodes, and the edge model is constructed based on the spatial position relationship and communication constraint conditions among the satellite nodes, civil aircraft nodes, and ground station nodes;

[0007] Based on a large constellation satellite orbit prediction algorithm, predict the orbital positions of satellite nodes within a preset time;

[0008] Based on the orbital positions of satellite nodes and the communication constraint conditions with space-air-ground, dynamically construct a space-air-ground communication link;

[0009] Based on an inter-satellite routing screening algorithm, screen out the optimal communication link from the constructed space-air-ground communication links.

[0010] Optionally, the process of constructing the spatial positions of the nodes of the large constellation space-air-ground communication network includes:

[0011] Construct the spatial distribution of the multi-layer heterogeneous constellation satellites, and determine the spatial positions of the satellite nodes in the inertial system;

[0012] Based on the route data of civil aircraft, generate the spatial positions of the civil aircraft nodes in the inertial system;

[0013] Based on the positions of the ground stations in the Earth-fixed coordinate system, convert them into the spatial positions of the ground nodes in the inertial system.

[0014] Optionally, the process of predicting the orbital positions of satellite nodes within a preset time based on the large constellation satellite orbit prediction algorithm includes:

[0015] Based on the functional relationship between the second-order zonal harmonic perturbation of the Earth, the gravitational constant of the Earth, the radius of the Earth, and pi, predict the change in the right ascension of the ascending node of the satellite and the change in the true anomaly of the satellite.

[0016] Optionally, the process of dynamically constructing the space-air-ground communication link based on the orbital positions of the satellite nodes and the communication constraints with the space-air-ground includes:

[0017] Based on the relative position and velocity constraints between satellite nodes, activate the satellite-satellite link;

[0018] Based on the elevation angle constraint between the satellite node and the ground target, activate the satellite-ground station link and the satellite-civil aircraft link;

[0019] Based on the relative position constraint between the civil aircraft and the ground station, activate the civil aircraft-ground station link.

[0020] Optionally, the inter-satellite routing screening algorithm includes:

[0021] Prioritize selecting the path with the minimum number of hops from the starting point to the ending point; if there are several paths with the minimum number of hops, prioritize selecting the path with the closest total spatial distance between nodes.

[0022] Optionally, the process of screening the satellite-ground station link based on the inter-satellite routing screening algorithm includes:

[0023] For the screening of the satellite-ground station link, among all the satellites with the activation function of the edge connected to the ground station being 1, select the one with the smallest included angle of the geocentric distance as the communication node.

[0024] Optionally, the process of screening the satellite-civil aircraft link based on the inter-satellite routing screening algorithm includes:

[0025] For the screening of the satellite-civil aircraft link, among all the satellites with the activation function of the edge connected to the civil aircraft being 1, select the one with the smallest included angle of the geocentric distance as the communication node.

[0026] The present invention also provides a computer device, including a memory, a processor, and a computer program stored on the memory, and the processor executes the computer program to implement the steps of the method.

[0027] The present invention also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the method are implemented.

[0028] The present invention also provides a computer program product, including a computer program, and when the computer program is executed by a processor, the steps of the method are implemented.

[0029] Compared with the prior art, the present invention has the following advantages and technical effects:

[0030] Based on the connectivity constraint conditions of the inter-satellite links of large constellations, the present invention constructs a space-air-ground communication link with satellites, civil aircraft, and ground stations as nodes and space-air-ground communication links as network edges, which can lay a theoretical reference for the construction of civil aircraft space-air-ground communication links supported by large constellation communication networks. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings constituting a part of this application are used to provide a further understanding of this application. The schematic embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation to this application. In the drawings:

[0032] Figure 1 is a schematic flowchart of the method of an embodiment of the present invention;

[0033] Figure 2 is a schematic diagram of the aircraft-large constellation-ground station communication link constructed in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will refer to the drawings and combine the embodiments to detail this application.

[0035] It should be noted that the steps shown in the flowchart of the drawings can be executed in a computer system such as a set of computer-executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0036] Embodiment 1

[0037] As Figure 1 shown, this embodiment provides a method for constructing a civil aircraft space-air-ground communication link based on a large satellite constellation, including the following steps:

[0038] Construct a sky-earth communication network node and link model for a large constellation. The nodes include satellite nodes, civil aircraft nodes, and ground station nodes. The link model is constructed based on the spatial position relationship and communication constraint conditions among the satellite nodes, civil aircraft nodes, and ground station nodes;

[0039] Based on the large constellation satellite orbit prediction algorithm, predict the orbital positions of satellite nodes within a preset time;

[0040] Based on the orbital positions of satellite nodes and the communication constraint conditions with the sky-earth, dynamically construct sky-earth communication links;

[0041] Based on the inter-satellite routing screening algorithm, screen out the optimal communication links from the constructed sky-earth communication links.

[0042] As an implementable approach, the process of constructing the spatial positions of the sky-earth communication network nodes for a large constellation includes:

[0043] 1) Satellite nodes:

[0044] In this embodiment, the spatial distribution of multi-layer heterogeneous constellation satellites is constructed. Denote t 0 as the starting time of the simulation. The spatial distribution of satellites at this time in the system is described as follows:

[0045] Γ γ : altitude layer, γ = 1, 2, …, γ_max;

[0046] a γ : semi-major axis of the satellites in the γ-th altitude layer;

[0047] e γ : eccentricity of the satellites in the γ-th altitude layer;

[0048] i γ : orbital inclination of the satellites in the γ-th altitude layer;

[0049] ω γ : argument of perigee of the satellites in the γ-th altitude layer;

[0050] Ω γ : right ascension of the ascending node of the satellites in the γ-th altitude layer;

[0051] N γ-Ω : number of orbital planes of the satellites in the γ-th altitude layer;

[0052] Ω 0 : at the starting time t 0 , right ascension of the ascending node of the first orbital plane;

[0053] N γ-f : number of satellites on each orbital plane of the satellites in the γ-th altitude layer;

[0054] f0 : The starting time t of the simulation 0 , the true anomaly of the first satellite in each orbital plane.

[0055] Thus, for the jth γ-Ω orbital plane in altitude layer γ, the serial number of the jth γ-f satellite is represented as γ / j γ-Ω / j γ-f . At time t 0 , the six orbital elements of this satellite are:

[0056]

[0057] Among them:

[0058]

[0059] The spatial position of the satellite in the orbital coordinate system can be derived from the six orbital elements:

[0060]

[0061] The rotation matrix from the orbital coordinate system to the inertial coordinate system is:

[0062]

[0063] The position of the satellite in the inertial coordinate system is:

[0064]

[0065] 2) Civil aircraft node:

[0066] The civil aircraft nodes considered in this embodiment can be generated from the route data. The specific parameters include the spatial positions of the civil aircraft in the Earth-fixed coordinate system at different times:

[0067]

[0068] The Earth-fixed coordinate system (with the origin at the center of the Earth, the X-axis pointing to the intersection of the prime meridian and the equator, the Z-axis parallel to the Earth's axis and pointing to the North Pole, and the Y-axis satisfying the right-hand coordinate system. Hereinafter referred to as the Earth-fixed system), the angular velocity of rotation relative to the Earth inertial coordinate system (with the origin at the center of the Earth, the x-axis in the equatorial plane and pointing to the vernal equinox, the z-axis parallel to the Earth's axis and pointing to the North Pole, and the y-axis satisfying the right-hand coordinate system. Hereinafter referred to as the inertial system) is ω e = 7.292×10 -5 rad / s. Denote t G as 12:00 on January 1, 2000. The geographical longitude of the aircraft in the Earth-fixed coordinate system is λ, and the geographical longitude in the J2000 inertial coordinate system is φ. Then at time t 1 there is:

[0069] φ = λ + ω e t 1 -t G (8)

[0070] Then its spatial position in the J2000 inertial system is:

[0071]

[0072] 3) Ground station node:

[0073] Denote the longitude of the ground station as φ and the latitude as θ in the Earth-fixed coordinate system. Then its position in the J2000 inertial system can be characterized as:

[0074]

[0075] As an implementable method, the process of predicting the orbital positions of satellite nodes within a preset time based on the large constellation satellite orbit prediction algorithm includes: predicting the change in the right ascension of the ascending node of the satellite and the change in the true anomaly of the satellite based on the functional relationship between the second-order zonal harmonic perturbation of the Earth, the gravitational constant of the Earth, the radius of the Earth, and pi.

[0076] Specifically, since giant constellations usually adopt orbit maintenance to keep them operating on a predetermined orbit. Therefore, this embodiment only considers the J 2 -term orbital perturbation factors. Then, the change in the right ascension of the ascending node of the satellite during the Δt time period can be expressed as:

[0077]

[0078] where J 2 = 1.08263×10 -3 , is the second-order zonal harmonic term of the Earth; μ = 398603 m 3 / s 2 , is the gravitational constant of the Earth; R e = 6378 km, is the radius of the Earth; π is pi.

[0079] Since the Walker constellation is a near-circular orbit, here e γ is approximately taken as 0. Then the change in the true anomaly of the satellite during the Δt time period can be expressed as:

[0080]

[0081] As an implementable method, the process of dynamically constructing the space-ground communication link based on the orbital positions of satellite nodes and the communication constraint conditions between space, sky, and ground includes:

[0082] Activating the satellite-satellite link based on the relative position and velocity constraints between satellite nodes;

[0083] Based on the elevation angle constraint between the satellite node and the ground target, activate the satellite-ground station link and the satellite-civil aircraft link;

[0084] Based on the relative position constraint between the civil aircraft and the ground station, activate the civil aircraft-ground station link.

[0085] Specifically:

[0086] 1) The link edge activation function of "satellite-satellite" is as follows:

[0087] A) For adjacent satellites in the same orbital plane, since they are relatively stationary to each other, the activation function is always 1.

[0088] B) For adjacent satellites in adjacent orbital planes, if their relative velocity is always less than the relative velocity threshold of the inter-satellite link within Δt, the inter-satellite link activation function is 1; otherwise it is 0.

[0089] C) For satellites in different altitude layers, denote the satellite in the H A layer (higher layer) as A p , and the satellite in the H B layer (lower layer) as B p . If B p is the one with the smallest relative distance among all the H j layer satellites that "satisfy the relative position and velocity constraints with A p at time t" in the lower layer satellites, then the inter-satellite link activation function between the two is 1; otherwise it is 0. B e

[0090] D) To eliminate the interference of the Earth's occlusion on the inter-satellite link, the maximum distance between satellites in the same orbital layer shall not exceed:

[0091]

[0092] where R e is the radius of the Earth and h is the satellite orbital altitude.

[0093] 2) "Satellite-ground station / civil aircraft" link:

[0094] Denote the ground target (aircraft or ground station) as φ and the satellite as A p . If A p is the one with the largest elevation angle among all the satellites that "meet the elevation angle threshold for φ", then the activation function is 1; otherwise it is 0.

[0095] 3) "Civil aircraft-ground station" link:

[0096] When the aircraft is within the coverage area of the ground station, the activation function is 1; otherwise it is 0.

[0097] As an implementable approach, the inter-satellite routing screening algorithm includes: preferentially selecting the path with the minimum number of hops from the starting point to the ending point; if there are several paths with the minimum number of hops, preferentially selecting the path with the closest total spatial distance between nodes.

[0098] Further, for the screening of satellite-ground station communication links, among all the satellites with the link activation function to the ground station being 1, the one with the minimum included angle of the geocentric distances is screened as the communication node. The geocentric distance between the satellite and the ground station can be calculated by the following formula:

[0099]

[0100] Further, for the screening of satellite-civil aircraft communication links, among all the satellites with the link activation function to the civil aircraft being 1, the one with the minimum included angle of the geocentric distances is screened as the communication node. The geocentric distance between the satellite and the civil aircraft can be calculated by the following formula:

[0101]

[0102] As a specific embodiment, a large constellation deployment plan is set based on the above method, as shown in Table 1:

[0103] Table 1

[0104]

[0105] At time t, the position of the aircraft is 127.0° east longitude and 37.1° north latitude, and the position of the ground station is 83.2° west longitude and 31.0° north latitude. Thus, an aircraft-large constellation-ground station communication link can be constructed as Figure 2 shown.

[0106] Embodiment 2

[0107] This embodiment also provides a computer device, including a memory, a processor, and a computer program stored on the memory, and the processor executes the computer program to implement the steps of the method.

[0108] Embodiment 3

[0109] This embodiment also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the method are implemented.

[0110] Embodiment 4

[0111] This embodiment also provides a computer program product, including a computer program, and when the computer program is executed by a processor, the steps of the method are implemented.

[0112] The above are only the preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for constructing a civil aircraft space-to-ground communication link based on a large satellite constellation, characterized in that: The following steps are involved: Construct a large-scale constellation space-to-ground communication network node and edge model, wherein the nodes include satellite nodes, civil aircraft nodes and ground station nodes, and the edge model is constructed based on the spatial position relationship and communication constraints between satellite nodes, civil aircraft nodes and ground station nodes; Based on the large constellation satellite orbit prediction algorithm, the orbital position of the satellite node is predicted within the preset time; Based on the orbital position of the satellite node and the communication constraints with the space and the ground, the space-ground communication link is dynamically constructed; Based on the inter-satellite routing screening algorithm, the optimal communication link is selected from the constructed space-to-ground communication links.

2. The method according to claim 1, characterized in that: The process of constructing the spatial locations of nodes in a large constellation space-to-ground communication network includes: Construct the spatial distribution of multi-layer heterogeneous constellation satellites and determine the spatial position of satellite nodes in the inertial system; Based on the flight route data of civil aircraft, the spatial position of the civil aircraft node in the inertial system is generated; Based on the position of the ground station in the earth-fixed coordinate system, it is converted into the spatial position of the ground node in the inertial system.

3. The method according to claim 1, characterized in that Based on the large constellation satellite orbit prediction algorithm, the process of predicting the orbital position of the satellite node within the preset time includes: Based on the functional relationship between the second-order harmonic perturbation of the Earth, the Earth's gravitational constant, the Earth's radius and pi, the changes in the right ascension of the satellite ascending node and the true anomaly longitude of the satellite are predicted.

4. The method according to claim 1, characterized in that Based on the orbital position of the satellite node and the communication constraints with the space and ground, the process of dynamically building the space-ground communication link includes: Activate satellite-satellite links based on relative position and velocity constraints between satellite nodes; Based on the pitch angle constraint between the satellite node and the ground target, the satellite-ground station link and the satellite-civil aircraft link are activated; Based on the relative position constraints between the civil aircraft and the ground station, the civil aircraft-ground station link is activated.

5. The method according to claim 1, characterized in that: The inter-satellite routing screening algorithm comprises: The path with the minimum number of hops from the starting point to the end point is given priority; if there are several paths with the minimum number of hops, the path with the shortest total spatial distance between nodes is given priority.

6. The method according to claim 5, characterized in that Based on the inter-satellite routing screening algorithm, the process of screening satellite-ground station links includes: For satellite-ground station link screening, among all satellites whose edge activation function with the ground station is 1, the one with the smallest angle from the center of the earth is selected as the communication node.

7. The method according to claim 5, characterized in that Based on the inter-satellite routing screening algorithm, the process of screening satellite-civilian aircraft links includes: For satellite-civilian aircraft link screening, among all satellites with activation functions of 1 connected to civil aircraft, the one with the smallest angle from the center of the earth is selected as the communication node.

8. A computer device comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the steps of the method according to any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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