Giant constellation inter-satellite communication network construction method based on complex network

Abstract

The invention relates to a giant constellation inter-satellite communication network construction method based on a complex network, and the method comprises the steps: obtaining the number of satellite orbits at a starting moment according to the spatial distribution of satellites at the starting moment in a system; according to a giant constellation satellite orbit forecasting algorithm, acquiring right ascension changes and true anomaly changes of ascending nodes of satellites in a preset time period; on the basis of the right ascension change and true anomaly change of the ascending node of the satellite in the preset time period, obtaining the number of satellite orbits in the preset time period; constructing an inter-satellite link based on the number of satellite orbits at the starting moment and the number of satellite orbits in the preset time period; and constructing a complex network model by taking the inter-satellite link as a connecting edge and taking a satellite as a node. According to the method, a complex network model is constructed by taking satellites as nodes and taking inter-satellite links as connecting edges on the basis of a giant constellation inter-satellite link connection constraint condition, the method is oriented to a complex system consisting of thousands of satellites, and the influence of inter-satellite cooperation capability on the stability of the system can be fully considered.

Description

Technical Field

[0001] The present invention relates to the field of satellite communication technology, and in particular to a method for constructing a giant constellation inter-satellite communication network based on a complex network. Background Art

[0002] With the high-speed deployment of large-scale low-orbit heterogeneous constellations represented by Starlink and OneNet, the application of satellite-based Internet in the future communication field is an inevitable trend. In 2016, my country began to comprehensively lay out satellite communication systems. China Aerospace Science and Technology and China Aerospace Science and Industry Corporation launched the "Hongyan Constellation" and "Hongyun Project" respectively. In 2020, my country included "satellite Internet" in the new infrastructure. In September 2021, my country has successfully completed the integration test of low-orbit broadband satellites and smart 5G private networks. In October 2022, SpaceX officially launched the "Starlink Aviation" service to provide airlines with "high-speed, low-latency, globally connected flight Internet". Unlike traditional medium and high-orbit satellite-based communications, the low-orbit constellation has a short transit time to the ground under the coverage area of ​​a single satellite, and the inter-satellite networking technology is not yet mature. It is still in the research and development, testing and verification stage worldwide. With the rapid development of satellite-based Internet, research on inter-satellite routing strategies for large-scale low-orbit heterogeneous constellations can provide a theoretical basis for constellation deployment, inter-satellite networking strategy design and optimization, which is of great significance and urgent need.

[0003] Unlike traditional medium and high orbit constellation networking, large low-orbit constellations have a large number of satellites, relatively fast speeds, and a small ground coverage area for a single satellite, which makes the layout planning of the constellation configuration more complicated. In 2016, J. Alvarez et al. discussed the relationship between large constellation configuration and communication capabilities, and summarized the key issues in the deployment process of large constellations; in 2021, Oltjon Kodheli et al. looked forward to the application prospects of large constellation communications, and proposed that the aviation field use large low-orbit constellations to deploy space-based ADS-B (Automatic Dependent Surveillance-Broadcast) receivers, and use low-orbit satellites as part of civil aviation traffic control to achieve low latency and global coverage of the ADS-B system. In 2020, Li Shun of Beijing University of Posts and Telecommunications analyzed the design and performance of LEO satellite network routing strategies, designed a routing strategy suitable for LEO satellite system networks, and built a LEO satellite network platform based on orbit design software STK and network simulation software. In 2022, Zheng Dan of Chongqing University of Posts and Telecommunications conducted an in-depth study of routing selection technology in low-orbit satellite networks.

[0004] However, most existing studies are based on homogeneous constellation systems, that is, it is assumed that low-orbit constellation satellites have unique orbital altitudes and orbital inclinations. In reality, due to the limited carrying capacity of space resources at the same orbital altitude, constellation systems are often distributed at multiple different orbital altitudes and inclinations. As the constellation deployment configuration becomes more complex, inter-satellite routing research will also gradually deepen. Therefore, the present invention provides a method for constructing a giant constellation inter-satellite communication network based on a complex network. Summary of the invention

[0005] The purpose of the present invention is to provide a method for constructing a giant constellation inter-satellite communication network based on a complex network, based on the connectivity constraints of the giant constellation inter-satellite links, with satellites as nodes and inter-satellite links as edges, to construct a complex network model.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A method for constructing a giant constellation inter-satellite communication network based on a complex network, comprising:

[0008] According to the spatial distribution of satellites in the system at the starting time, the number of satellite orbit elements at the starting time is obtained;

[0009] According to the giant constellation satellite orbit prediction algorithm, obtain the satellite ascending node right ascension change and true anomaly longitude change during the preset period;

[0010] Based on the change of the right ascension of the satellite ascending node and the change of the true anomaly angle during the preset period, obtaining the number of satellite orbit elements during the preset period;

[0011] Building an intersatellite link based on the number of satellite orbit elements at the starting time and the number of satellite orbit elements during the preset time period;

[0012] A complex network model is constructed by taking the intersatellite links as edges and the satellites as nodes.

[0013] Optionally, the method for obtaining the number of satellite orbit elements at the start time is:

[0014]

[0015] Among them, sate(γ / j γ-Ω / j γ-f |t0) is the jth altitude layer γ γ-Ω orbital plane, the jth γ-f satellites, the number of orbital elements at time t0, a γ is the semi-major axis of the satellite at the γth altitude layer, e γ is the eccentricity of the satellite at the γth altitude layer, incl γ is the orbital inclination of the satellite at the γth altitude layer, Ω0 is the simulation start time t0, the right ascension of the ascending node of the first orbital plane, N γ-Ωis the orbital plane number of the satellite in the γth altitude layer, j γ-Ω For the jth γ-Ω orbital plane, ω γ is the perigee angle of the satellite at the γth altitude layer, f0 is the simulation start time t0, the true perigee angle of the first satellite on each orbital plane, N γ-f is the number of satellites on each orbital plane of the γ-th altitude layer, j γ-f For the jth γ-f satellites.

[0016] Optionally, the method for obtaining the change in right ascension of the satellite ascending node during a preset period is:

[0017]

[0018] Where Ω is the change in the right ascension of the satellite ascending node during the Δt period, Δt is the Δt period, and R e is the radius of the earth, n is the average angular velocity of the satellite, J2 is the second-order harmonic of the earth, T is the orbital period, and μ is the gravitational constant of the earth.

[0019] Optionally, the method for obtaining the change of the true anomaly angle during a preset period is:

[0020]

[0021] Wherein, Δf is the change of the true anomaly of the satellite during the period Δt.

[0022] Optionally, building an intersatellite link includes:

[0023] For a satellite in the same orbital plane, based on the number of satellite orbit elements at the starting time and the number of satellite orbit elements during the preset period, an inter-satellite link in the same orbital plane is established between the satellite and an adjacent satellite in the same orbital plane:

[0024] link(sate(γ / j γ-Ω / j γ-f ),sate(γ / j γ-Ω / j γ-f ±1));

[0025] For satellites in different orbital planes, based on the number of satellite orbital elements at the starting time and the number of satellite orbital elements during the preset period, an inter-satellite link between the satellite and a satellite in the same phase in the adjacent orbital plane is constructed:

[0026] link(sate(γ / j γ-Ω / j γ-f ),sate(γ / j γ-Ω ±1 / j γ-f ));

[0027] For satellites at different altitudes, when the distance between the two satellites is less than Rangemax When constructing intersatellite links at different altitudes:

[0028] link(sate(γ1),sate(γ2)),Range(sate(γ1),sate(γ2))<Range max ;

[0029] Among them, sate(γ1) is any satellite at altitude level γ1, sate(γ2) is any satellite at altitude level γ2, Range max In order to meet the maximum inter-satellite distance constraint of communication conditions, Range(sate(γ1), sate(γ2)) is the spatial distance between the two satellites.

[0030] Optionally, the complex network model is an undirected simple graph G(V,E);

[0031] E={e ij =(v i , v j )|v i , v j ∈V}

[0032] Among them, E is the edge set, v i and v j is a node in the set V, e ij v i and v j The edges between them, V is the node set.

[0033] The beneficial effects of the present invention are as follows: Based on the connectivity constraints of intersatellite links of giant constellations, the present invention takes satellites as nodes and intersatellite links as edges to construct a complex network model. The construction of a complex network model of a giant constellation can lay a theoretical foundation for research on intersatellite information transmission efficiency, intersatellite communication network stability, key node identification, etc. Compared with the existing analysis ideas of single-satellite communication capabilities, the present invention is aimed at a complex system composed of tens of thousands of satellites, and can fully consider the impact of intersatellite collaboration capabilities on system stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 A flowchart of a method for constructing a giant constellation inter-satellite communication network based on a complex network according to an embodiment of the present invention;

[0036] Figure 2 This is a satellite orbit distribution diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] like Figure 1 This embodiment provides a method for constructing a giant constellation inter-satellite communication network based on a complex network, including:

[0040] According to the spatial distribution of satellites in the system at the starting time, the number of satellite orbit elements at the starting time is obtained;

[0041] According to the giant constellation satellite orbit prediction algorithm, obtain the satellite ascending node right ascension change and true anomaly longitude change during the preset period;

[0042] Based on the change of the right ascension of the satellite ascending node and the change of the true anomaly angle during the preset period, the number of satellite orbit elements during the preset period is obtained;

[0043] Building an intersatellite link based on the number of satellite orbit elements at the starting time and the number of satellite orbit elements during a preset period;

[0044] A complex network model is constructed by using intersatellite links as edges and satellites as nodes.

[0045] Furthermore, the method for obtaining the number of satellite orbit elements at the starting time is:

[0046]

[0047] Among them, sate(γ / j γ-Ω / j γ-f |t0) is the jth altitude layer γ γ-Ω orbital plane, the jth γ-f satellites, the number of orbital elements at time t0, a γ is the semi-major axis of the satellite at the γth altitude layer, e γ is the eccentricity of the satellite at the γth altitude layer, incl γ is the orbital inclination of the satellite at the γth altitude layer, Ω0 is the simulation start time t0, the right ascension of the ascending node of the first orbital plane, N γ-Ωis the orbital plane number of the satellite in the γth altitude layer, j γ-Ω For the jth γ-Ω orbital plane, ω γ is the perigee angle of the satellite at the γth altitude layer, f0 is the simulation start time t0, the true perigee angle of the first satellite on each orbital plane, N γ-f is the number of satellites on each orbital plane of the γ-th altitude layer, j γ-f For the jth γ-f satellites.

[0048] Specifically, this embodiment constructs the spatial distribution of multi-layer heterogeneous constellation satellites. Let t0 be the simulation start time, and the spatial distribution of satellites in the system at this time is described as follows:

[0049] Γ γ : altitude layer, γ=1,2,...,γ_max;

[0050] a γ : the semi-major axis of the satellite at the γth altitude layer;

[0051] e γ : the eccentricity of the satellite at the γth altitude layer;

[0052] incl γ : orbital inclination of the satellite at the γth altitude layer;

[0053] ω γ : the perigee angular distance of the satellite at the γth altitude layer;

[0054] Ω γ : right ascension of the ascending node of the γ-th altitude layer satellite;

[0055] N γ-Ω : The number of orbital planes of the satellite in the γth altitude layer;

[0056] Ω0: simulation start time t0, right ascension of the ascending node of the first orbital plane;

[0057] N γ-f : The number of satellites on each orbital plane of the γ-th altitude layer;

[0058] f0: The true anomaly angle of the first satellite in each orbital plane at the simulation start time t0.

[0059] Therefore, the jth γ-Ω orbital plane, the jth γ-f The satellite number is represented by γ / j γ-Ω / j γ-f At time t0, the six orbital elements of the satellite are as shown in formula (1).

[0060] Furthermore, the method for obtaining the change of the right ascension of the satellite ascending node during a preset period is:

[0061]

[0062] Among them, ΔΩ is the change of the satellite ascending node right ascension during the Δt period, Δt is the Δt period, R e is the radius of the earth, J2 is the second-order harmonic term of the earth, J2=1.08263×10 -3 , T is the orbital period, n is the average angular velocity of the satellite, μ is the Earth's gravitational constant μ = 398603m 3 / s 2 , π is the circumference of a circle.

[0063] Furthermore, the method for obtaining the change of the true anomaly angle during a preset period is:

[0064]

[0065] Wherein, Δf is the change of the true anomaly of the satellite during the period Δt.

[0066] Specifically, since giant constellations usually use orbit maintenance to keep them in the predetermined orbit, only the J2 orbit perturbation factor is considered here. Therefore, the change in the right ascension of the satellite ascending node during the Δt period can be expressed as shown in formulas (2)-(4).

[0067] Since the Walker constellation is a near-circular orbit, e is taken as an approximation here. γ = 0. Therefore, the satellite true anomaly angle during the Δt period can be expressed as shown in formula (5).

[0068] Calculate Δf and ΔΩ to replace sate(γ / j γ-Ω / j γ-f |t0) in the formula, Ω0 and f0 are used to obtain the number of satellite orbit elements during the preset period.

[0069] Furthermore, building an intersatellite link includes:

[0070] For satellites in the same orbital plane, based on the number of satellite orbital elements at the starting time and the number of satellite orbital elements during the preset period, an inter-satellite link in the same orbital plane is established between the satellite and the adjacent satellite in the same orbital plane:

[0071] link(sate(γ / j γ-Ω / j γ-f ), sate(γ / j γ-Ω / j γ-f ±1)) (6);

[0072] For satellites in different orbital planes, based on the number of satellite orbital elements at the starting time and the number of satellite orbital elements during the preset period, an inter-satellite link between the satellite and the satellite in the same phase in the adjacent orbital plane is constructed:

[0073] link(sate(γ / j γ-Ω / j γ-f ), sate(γ / j γ-Ω ±1 / j γ-f )) (7);

[0074] For satellites at different altitudes, when the distance between the two satellites is less than Range max When constructing intersatellite links at different altitudes:

[0075] link(sate(γ1),sate(γ2)),Range(sate(γ1),sate(γ2))<Range max (8);

[0076] Among them, sate(γ1) is any satellite at altitude level γ1, sate(γ2) is any satellite at altitude level γ2, Range(sate(γ1, sate(γ2)) is the spatial distance between the two satellites, Range max It is the maximum inter-satellite distance constraint for the inter-satellite link in the satellite design parameters, that is, the maximum inter-satellite distance constraint that satisfies the communication conditions. When the spatial distance between two satellites is less than the maximum inter-satellite distance constraint for the inter-satellite link in the satellite design parameters, the inter-satellite link is established; otherwise, there is no communication link between the two satellites.

[0077] Specifically, the relative position of the satellite orbit space is a constraint condition for constructing the intersatellite link. Referring to the constraints for constructing intersatellite links in existing large constellations such as STARLINK, this embodiment constructs an intersatellite link between a satellite and an adjacent satellite in the same orbital plane for satellites at the same altitude layer as shown in formula (6).

[0078] The spatial positions of all nodes (satellites) at time t0 can be calculated from the initial orbital elements of the large constellation at time t0, that is, formula (1). The spatial positions of all nodes (satellites) after the Δt period can be updated based on the initial orbital elements and combined with the orbit prediction algorithms in (2) to (5) to update the satellite orbital elements.

[0079] Similarly, an inter-satellite link is constructed between a satellite and a satellite with the same phase in an adjacent orbital plane, as shown in formula (7).

[0080] For satellites at different altitudes, when the distance between the two satellites is less than Range max When , the intersatellite link is constructed, as shown in formula (8).

[0081] Furthermore, the complex network model is an undirected simple graph G(V,E);

[0082] E={e ij =(v i , vj )|v i , v j ∈V} (9)

[0083] Among them, E is the edge set, v i and v j is a node in the set V, e ij v i and v j The edges between them, V is the node set.

[0084] Specifically, a path in a network refers to a sequence consisting of a set of nodes, where every two consecutive vertices in the sequence are connected by edges in the network.

[0085] This embodiment takes the 550km altitude layer and 340 altitude layer satellite system of the STARLINK giant constellation as an example to construct its inter-satellite link complex network model. Specifically:

[0086] There are 1584 satellites at an altitude of 550km, with an orbital inclination of 53°, 72 orbital planes in total, and 22 satellites in each orbital plane.

[0087] There are 5,280 satellites at an altitude of 340km, with an orbital inclination of 53°, 48 orbital planes, and 110 satellites in each orbital plane.

[0088] Altitude layer Γ1 = 550km, the semi-major axis a1 of the satellite at the Γ1 altitude layer = 550km + 6378km; 6378km is the radius of the earth. Eccentricity e1 = 0, orbital inclination incl1 = 53°, perigee angular distance ω0 = 0. The right ascensions of the ascending nodes of the 72 orbital planes at time t0 are:

[0089]

[0090] The true anomaly angle of 22 satellites in each orbital plane at time t0 is:

[0091]

[0092] Altitude layer Γ2 = 340km, the semi-major axis of the satellite at the Γ2 altitude layer a2 = 340km + 6378km; eccentricity e2 = 0, orbital inclination incl2 = 53°, perigee angular distance ω0 = 0. The right ascensions of the ascending nodes of the 48 orbital planes at time t0 are:

[0093]

[0094] The true anomaly angle of 110 satellites in each orbital plane at time t0 is:

[0095]

[0096] The above satellites are distributed as follows: Figure 2 As shown, there are two altitude layers (one altitude layer is 550km with 1584 satellites; the other altitude layer is 40km with 5280 satellites).

[0097] From formula (2), we can know that the precession rate of the right ascension of the ascending node of the satellite at altitude level Γ1 is -4.49° per year; the precession rate of the right ascension of the ascending node of the satellite at altitude level Γ2 is -5° per year.

[0098] From formula (5), we can know that the true anomaly precession speed of the satellite at altitude layer Γ1 is 0.0627° per second; the true anomaly precession speed of the satellite at altitude layer Γ2 is 0.0655° per second.

[0099] The 72 orbital planes of the satellites at altitude layer Γ1 and the 22 satellites in each orbital plane constitute a total of 72*22 inter-satellite links in the same orbital plane; and 22*72 inter-satellite links in different orbital planes.

[0100] The 48 orbital planes of the altitude layer Γ2 satellites and the 110 satellites in each orbital plane constitute a total of 48*110 inter-satellite links in the same orbital plane; and 110*48 inter-satellite links in different orbital planes.

[0101] Remember the Range between two altitude layers max =500km, then there are 500 intersatellite links at time t0.

[0102] This forms a complex network with 6864 nodes and 14228 edges.

[0103] The embodiments described above are only descriptions of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for constructing a giant constellation inter-satellite communication network based on a complex network, characterized in that: include: According to the spatial distribution of satellites in the system at the starting time, the number of satellite orbit elements at the starting time is obtained; According to the giant constellation satellite orbit prediction algorithm, obtain the satellite ascending node right ascension change and true anomaly longitude change during the preset period; Based on the change of the right ascension of the satellite ascending node and the change of the true anomaly angle during the preset period, obtaining the number of satellite orbit elements during the preset period; Building an intersatellite link based on the number of satellite orbit elements at the starting time and the number of satellite orbit elements during the preset time period; A complex network model is constructed by taking the intersatellite links as edges and the satellites as nodes.

2. The method for constructing a giant constellation inter-satellite communication network based on a complex network according to claim 1, characterized in that: The method to obtain the number of satellite orbit elements at the starting time is: Among them, sate(γ / j γ-Ω / j γ-f |t0) is the jth altitude layer γ γ-Ω orbital plane, the jth γ-f satellites, the number of orbital elements at time t0, a γ is the semi-major axis of the satellite at the γth altitude layer, e γ is the eccentricity of the satellite at the γth altitude layer, incl γ is the orbital inclination of the satellite at the γth altitude layer, Ω0 is the simulation start time t0, the right ascension of the ascending node of the first orbital plane, N γ-Ω is the orbital plane number of the satellite in the γth altitude layer, j γ-Ω For the jth γ-Ω orbital plane, ω γ is the perigee angle of the satellite at the γth altitude layer, f0 is the simulation start time t0, the true perigee angle of the first satellite on each orbital plane, N γ-f is the number of satellites on each orbital plane of the γ-th altitude layer, j γ-f For the jth γ-f satellites.

3. The method for constructing a giant constellation inter-satellite communication network based on a complex network according to claim 2, characterized in that: The method for obtaining the change of right ascension of the satellite ascending node during the preset period is: Among them, ΔΩ is the change of the satellite ascending node right ascension during the Δt period, Δt is the Δt period, R e is the radius of the earth, n is the average angular velocity of the satellite, J2 is the second-order harmonic of the earth, T is the orbital period, and μ is the gravitational constant of the earth.

4. The method for constructing a giant constellation inter-satellite communication network based on a complex network according to claim 3, characterized in that: The method for obtaining the change of true anomaly angle during a preset period is: Wherein, Δf is the change of the true anomaly of the satellite during the period Δt.

5. The method for constructing a giant constellation inter-satellite communication network based on a complex network according to claim 2, characterized in that: Building an intersatellite link includes: For a satellite in the same orbital plane, based on the number of satellite orbit elements at the starting time and the number of satellite orbit elements during the preset period, an inter-satellite link in the same orbital plane is established between the satellite and an adjacent satellite in the same orbital plane: link(sate(c / j γ-Ω / j γ-f ),sate(γ / j γ-Ω / j γ-f ±1)); For satellites in different orbital planes, based on the number of satellite orbital elements at the starting time and the number of satellite orbital elements during the preset period, an inter-satellite link between the satellite and a satellite in the same phase in the adjacent orbital plane is constructed: link(sate(c / j γ-Ω / j γ-f ),sate(γ / j γ-Ω ±1 / j γ-f )); For satellites at different altitudes, when the distance between the two satellites is less than Range max When constructing intersatellite links at different altitudes: link(sate(γ1),sate(γ2)),Range(sate(γ1),sate(γ2))<Range max ; Among them, sate(γ1) is any satellite at altitude level γ1, sate(γ2) is any satellite at altitude level γ2, Range max In order to meet the maximum inter-satellite distance constraint of communication conditions, Range(sate(γ1), sate(γ2)) is the spatial distance between the two satellites.

6. The method for constructing a giant constellation inter-satellite communication network based on a complex network according to claim 1, characterized in that: The complex network model is an undirected simple graph G(V,E); E={e ij =(v i ,v j )|v i ,v j ∈V} Among them, E is the edge set, v i and v j is a node in the set V, e ij v i and v j The edges between them, V is the node set.

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