Inter-satellite link communication simulation method, system and program product based on satellite constellation

Abstract

The invention provides an inter-satellite link communication simulation method and system based on a satellite constellation and a program product, and the method comprises the following steps: calculating the position and speed data of at least two satellites in a preset time sequence based on a satellite orbit parameter and acting force model; calculating attitude data of the at least two satellites in a preset time sequence based on the satellite attitude parameters and an attitude dynamics model; on the basis of the position, speed and attitude data and preset link parameters, inter-satellite link key parameters between the at least two satellites are calculated, and the key parameters comprise link delay, bandwidth, signal strength and bit error rate; and carrying out three-dimensional visual display on the position, speed, attitude data and inter-satellite link key parameters. The problems that in the prior art, a simulation system cannot comprehensively reflect the actual communication condition, and it is difficult to accurately simulate the electromagnetic wave propagation particularity in the space environment are solved, the performance of the communication link can be predicted more accurately, and the reliability of inter-satellite communication link simulation is enhanced.

Description

Technical Field

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

[0002] With the acceleration of global informatization, satellite communication technology is developing at an unprecedented pace. The concept of satellite constellations, in particular, is being widely applied in a variety of fields, including global navigation and positioning, remote sensing monitoring, and broadband internet access. In recent years, with technological advances and cost reductions, the deployment of small and microsatellites has become increasingly common, and the scale of satellite constellations has continued to expand. This trend has spawned new application scenarios, such as integrated space-ground networks, which aim to seamlessly integrate satellite communications with terrestrial communication networks to form a high-speed, stable information transmission network covering the entire globe. Against this backdrop, the design and operation of satellite constellations face unprecedented challenges, particularly in achieving efficient and stable communications in intersatellite networks to meet the growing demand for data transmission.

[0003] However, satellite constellation technology still faces numerous challenges in actual deployment and application, particularly in space-based edge computing scenarios, where multi-satellite collaborative operations rely heavily on intersatellite communications. Existing simulation systems have significant shortcomings in this area. Most focus on simulating satellite orbits and attitudes, ignoring the complexity and dynamics of intersatellite communication links. This results in simulation results that fail to fully reflect actual communication conditions. Even some systems that attempt to incorporate communication link simulation often struggle to accurately simulate the specific characteristics of electromagnetic wave propagation in space, such as free-space attenuation, multipath effects, atmospheric refraction, and the impact of these factors on communication quality, due to model simplification and inappropriate parameter settings. Furthermore, they struggle to provide intuitive and convenient monitoring and control methods, limiting researchers' ability to conduct in-depth analysis and optimization of satellite constellation performance. Therefore, a simulation method that can comprehensively simulate satellite orbits, attitudes, and communication links is urgently needed to study and optimize the performance of intersatellite communication systems and improve their reliability and efficiency in practical applications.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to ordinary technicians in this field. Summary of the Invention

[0005] In view of this, the present invention provides a satellite constellation-based inter-satellite link communication simulation method, system and program product to overcome the problems in the existing technology that the simulation system cannot fully reflect the actual communication conditions and is difficult to accurately simulate the particularities of electromagnetic wave propagation in the space environment. It can realize comprehensive simulation of satellite orbits, attitudes and key parameters of inter-satellite links, and provide a more accurate basis for the design, optimization and performance evaluation of satellite constellations.

[0006] An embodiment of the present invention provides a method for simulating inter-satellite link communication based on a satellite constellation, comprising the following steps:

[0007] Calculate the position and velocity data of at least two satellites in a predetermined time series based on satellite orbit parameters and a force model;

[0008] Calculate the attitude data of at least two satellites in a predetermined time series based on satellite attitude parameters and attitude dynamics model;

[0009] Calculate key parameters of the inter-satellite link between at least two satellites based on position, velocity, and attitude data and pre-set link parameters, including link delay, bandwidth, signal strength, and bit error rate;

[0010] The position, velocity, attitude data and key parameters of the intersatellite link are displayed in three dimensions.

[0011] In some optional embodiments, in the step of calculating satellite position and velocity data, the satellite orbit parameters include six orbital elements.

[0012] In some optional embodiments, in the step of calculating satellite position and velocity data, the force model includes at least one of an Earth non-spherical gravity model, an atmospheric drag model, and a solar radiation pressure model. The Earth non-spherical gravity model includes at least J2 and J4 perturbation terms. The atmospheric drag model calculates the atmospheric drag perturbation based on the atmospheric density model, and the solar radiation pressure model calculates the solar radiation pressure perturbation based on satellite reflection characteristics and a solar constant.

[0013] In some optional embodiments, in the step of calculating satellite attitude data, quaternions are used to represent the satellite attitude, and the attitude dynamics model takes into account the influence of external interference torques. The external interference torque includes at least one of gravity gradient torque, solar radiation pressure torque, and aerodynamic torque; the inter-satellite distance is calculated based on the position data, and the link delay is calculated based on the inter-satellite distance and signal propagation speed; the free space propagation loss is calculated based on the inter-satellite distance calculated by the position data; the antenna pointing loss is calculated based on the antenna pointing deviation calculated by the attitude data and the position data, and a preset antenna gain pattern; and the received signal strength is calculated based on the transmit power, antenna gain, and system loss among the preset link parameters, in combination with the free space propagation loss and / or antenna pointing loss.

[0014] In some optional embodiments, the step of calculating the key parameters of the intersatellite link includes: calculating the link bandwidth or data throughput based on the signal bandwidth and modulation order in the preset link parameters; calculating the energy per bit to noise power spectral density ratio (Eb / No) based on the received signal strength and the noise parameters in the preset link parameters, and calculating the bit error rate based on Eb / No and the Gaussian Q function.

[0015] In some optional embodiments, the step of performing three-dimensional visualization is performed using a game engine.

[0016] In some optional embodiments, the method further includes: receiving a user interaction instruction, and adjusting preset link parameters or controlling the execution of the calculation step according to the instruction.

[0017] Another aspect of an embodiment of the present invention provides a satellite constellation-based inter-satellite link communication simulation system, which is used to implement the steps of the above-mentioned satellite constellation-based inter-satellite link communication simulation method, including:

[0018] a satellite orbit simulation unit configured to calculate position and velocity data of at least two satellites in a predetermined time series based on satellite orbit parameters and a force model;

[0019] a satellite attitude simulation unit configured to calculate attitude data of at least two satellites in a predetermined time series based on satellite attitude parameters and an attitude dynamics model;

[0020] an intersatellite communication link simulation unit, communicatively connected to the satellite orbit simulation unit and the satellite attitude simulation unit, configured to receive position, velocity, and attitude data, and calculate key parameters of the intersatellite link between at least two satellites based on the received data and preset link parameters, the key parameters including link delay, bandwidth, signal strength, and bit error rate;

[0021] The visualization and interaction unit is connected to the intersatellite communication link simulation unit and is configured to receive position, velocity, attitude data and key parameters of the intersatellite link, and render and display the data in a three-dimensional visualization environment.

[0022] Another aspect of an embodiment of the present invention provides a satellite constellation-based inter-satellite link communication simulation program product, which includes computer instructions. When the computer instructions are executed by a processor, the steps of the above-mentioned satellite constellation-based inter-satellite link communication simulation method are implemented.

[0023] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

[0024] The satellite constellation-based inter-satellite link communication simulation method, system, and program product of the present invention have the following beneficial effects:

[0025] The intersatellite link communication simulation for a satellite constellation aims to simulate the in-orbit operation and communication processes of satellites. Its core objective is to accurately calculate the satellite's position, attitude, and intersatellite link communication quality. A satellite's orbital parameters determine its position in space, while the force model influences the accuracy of orbit calculations. For example, the Earth's non-spherical gravity, atmospheric drag, and solar radiation pressure all exert perturbations on the satellite's trajectory. The more accurate the force model, the closer the orbit calculation results are to reality. The satellite's attitude determines the antenna's pointing direction, which in turn affects the establishment of the communication link and the strength of the signal. The communication quality of the intersatellite link is affected by multiple factors, including the distance between satellites, the frequency of the signal, the antenna gain, and various losses in the space environment. By simulating these factors, key parameters such as link latency, bandwidth, signal strength, and bit error rate can be evaluated, providing a scientific basis for the design, optimization, and operation of satellite constellations. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Other features, objects and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0027] Figure 1 is a flow chart of a satellite constellation-based inter-satellite link communication simulation method according to an embodiment of the present invention;

[0028] Figure 2 1 is a schematic structural diagram of an inter-satellite link communication simulation system based on a satellite constellation according to an embodiment of the present invention;

[0029] Figure 3 It is a simulation flow diagram of an inter-satellite link communication simulation system based on a satellite constellation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be embodied in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0031] In addition, the accompanying drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale. Identical reference numerals in the figures denote identical or similar parts, and thus repetitive descriptions thereof will be omitted. Some of the block diagrams shown in the accompanying drawings are functional entities that do not necessarily correspond to physically or logically separate entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0032] The flowcharts shown in the accompanying drawings are merely exemplary and do not necessarily include all steps. For example, some steps may be decomposed, while some steps may be combined or partially combined. Therefore, the actual execution order may change according to actual circumstances.

[0033] This paper provides a method for simulating intersatellite link communications based on a satellite constellation. By establishing an intersatellite communication link simulation model, key intersatellite link metrics, namely link latency, bandwidth, signal strength, and bit error rate, can be calculated in real time. This allows researchers and engineers to predict communication link performance before actual satellite launch, thus providing a basis for optimizing satellite network design and operation. Furthermore, this paper can provide more accurate satellite orbit predictions and enhance the reliability of intersatellite communication link simulation by considering multiple influencing factors.

[0034] like Figure 1 As shown, the present invention provides an inter-satellite link communication simulation method based on a satellite constellation, comprising:

[0035] P100, based on satellite orbit parameters and force model, calculate the position and velocity data of at least two satellites in a predetermined time series;

[0036] P200, based on satellite attitude parameters and attitude dynamics model, calculate the attitude data of at least two satellites in a predetermined time series;

[0037] P300, based on the position data, velocity data, attitude data and preset link parameters, calculates key parameters of the inter-satellite link between at least two satellites, including link delay, bandwidth, signal strength and bit error rate;

[0038] P400, displays position data, velocity data, attitude data and key parameters of intersatellite links in three dimensions.

[0039] Satellite orbit parameters refer to parameters that describe the satellite's trajectory in space, such as the six orbital parameters: semi-major axis, eccentricity, inclination, right ascension of the ascending node, argument of periapsis, and true anomaly. These parameters define the shape, size, and direction of the satellite orbit. The force model describes the various forces that affect satellite motion, such as Earth's gravity, atmospheric drag, and solar radiation pressure. In the present invention, the satellite orbit parameters and the force model can be used to accurately calculate the satellite's position and velocity data in a predetermined time series, providing a basis for subsequent intersatellite link simulation. The force model can include at least one of the Earth's non-spherical gravity model, the atmospheric drag model, and the solar radiation pressure model. The Earth's non-spherical gravity model can include at least J2 and J4 perturbation terms. The atmospheric drag model calculates the atmospheric drag perturbation based on the atmospheric density model. The solar radiation pressure model calculates the solar radiation pressure perturbation based on the satellite's reflection characteristics and the solar constant. For example, the two-body model is selected as the satellite orbit model, and factors such as the irregularity of the Earth's gravity field, atmospheric drag, and solar radiation pressure are taken into account. The motion trajectory of the satellite under the Earth's gravity field is calculated based on the six orbital elements, and the J2 and J4 perturbation models are introduced to improve the accuracy of orbit prediction, especially in the prediction of long-term orbital evolution and high-orbit satellites.

[0040] Satellite attitude parameters, such as Euler angles and quaternions, describe the satellite's attitude in space. These parameters define the satellite's rotational state relative to the reference coordinate system. The attitude dynamics model describes how the satellite's attitude changes over time, influenced by various torques such as gravity gradient torque, solar radiation pressure torque, and aerodynamic torque. In embodiments of the present invention, satellite attitude parameters and the attitude dynamics model can be used to accurately calculate satellite attitude data over a predetermined time series, providing antenna pointing information for subsequent intersatellite link simulations. The external interference torque may include at least one of the gravity gradient torque, the solar radiation pressure torque and the aerodynamic torque; the inter-satellite distance is calculated based on the position data, and the link delay is calculated based on the inter-satellite distance and the signal propagation speed; the free space propagation loss is calculated based on the inter-satellite distance calculated based on the position data; the antenna pointing loss is calculated based on the antenna pointing deviation calculated based on the attitude data and the position data, and the preset antenna gain pattern; the attitude representation method may use Euler angles and quaternions to represent the satellite attitude, simulate the satellite's rotation, yaw, pitch and roll, apply the satellite attitude dynamics model to describe the change of the satellite attitude over time, consider external disturbances such as the earth's gravity gradient, solar radiation pressure, atmospheric resistance, etc., calculate the satellite's attitude change through numerical integration, and update the satellite's attitude in real time.

[0041] Link parameters refer to various parameters that affect the quality of the intersatellite communication link, such as transmit power, antenna gain, signal frequency, and modulation mode. In the present invention, using position, velocity, and attitude data along with preset link parameters, key intersatellite link parameters can be calculated, including link delay, bandwidth, signal strength, and bit error rate (BER). These parameters reflect the performance of the intersatellite communication link. The key parameter calculation steps include: calculating the link bandwidth or data throughput based on the signal bandwidth and modulation order in the preset link parameters; calculating the energy per bit to noise power spectral density ratio (Eb / No) based on the received signal strength and the noise parameters in the preset link parameters; and calculating the bit error rate based on Eb / No and the Gaussian Q function.

[0042] 3D visualization uses computer graphics technology to display satellite position, velocity, attitude data, and key intersatellite link parameters in a 3D image format. For example, Unreal Engine UE can be used for 3D visualization development. This visualization helps users intuitively understand the operating status of the satellite constellation and the performance of the intersatellite communication links.

[0043] Through the above steps, the present invention can comprehensively simulate the inter-satellite link communication process of a satellite constellation, providing technical support for satellite constellation design, optimization, and performance evaluation. By considering the combined influence of multiple factors, communication link performance can be more accurately predicted, reducing the risk of actual deployment, and helping to optimize satellite resource allocation and improve overall communication efficiency.

[0044] In some embodiments, in step P100 of calculating satellite position and velocity data, the satellite orbit parameters include six orbital elements. The six orbital elements are six basic parameters describing the satellite orbit state, namely the semi-major axis, eccentricity, inclination, right ascension of the ascending node, argument of perigee, and true anomaly. Through these parameters, the satellite orbit can be uniquely determined. Precise orbit parameters are a prerequisite for link simulation. Through these parameters, it is possible to accurately know the position of the satellite at a certain moment. When implementing the six orbital elements specifically, they include: the semi-major axis (a), which characterizes the size of the orbit and determines the period of the satellite's operation; the eccentricity (e), which characterizes the shape of the orbit. When e = 0, the orbit is circular, and when 0 < e < 1, the orbit is elliptical; the inclination (i), which characterizes the angle between the orbit plane and the reference plane (usually the Earth's equatorial plane); the right ascension of the ascending node (Ω), which characterizes the direction of the orbit plane in the reference plane; the argument of perigee (ω), which characterizes the position of the satellite on the orbit; and the true anomaly (ν), which characterizes the true position of the satellite along the orbit at a specific moment. These parameters together completely describe the satellite's orbit state in space and provide accurate orbit information for subsequent link simulation. For example, the two-body model can be used in combination with the six orbital elements to calculate the satellite's motion trajectory under the Earth's gravitational field. Specifically, by defining mathematical expressions, that is, the satellite acceleration, using the six orbital elements to describe the orbit state, including eccentricity, inclination, and right ascension of the ascending node, calculating the true anomaly through Kepler's equation and transformation formulas, and then calculating the satellite position using the elliptical orbit equation, introducing the J2 and J4 perturbation models, and considering the influence of the Earth's non-spherical shape on the orbit, more accurate orbit prediction can be provided.

[0045] Using the six orbital elements as satellite orbit parameters can achieve an accurate description of the satellite orbit state, provide reliable orbit information for subsequent inter-satellite link simulation, and improve the accuracy of simulation results.

[0046] In some embodiments, in step P100 of calculating satellite position and velocity data, the force model includes at least one of the Earth's non-spherical gravitational model, the atmospheric drag model, and the solar radiation pressure model. The Earth's non-spherical gravitational model includes at least J2 and J4 perturbation terms. The atmospheric drag model calculates the atmospheric drag perturbation based on the atmospheric density model, and the solar radiation pressure model calculates the solar radiation pressure perturbation based on the satellite reflection characteristics and the solar constant. The force model describes various forces affecting the satellite's motion. An accurate force model is an important guarantee for accurately calculating satellite position and velocity data.

[0047] Earth's non-spherical gravitational model: The Earth is not an ideal sphere, and its gravitational field has irregularities. The J2 and J4 perturbation terms are an approximate description of the Earth's gravitational field, considering the influence of the Earth's shape on the satellite orbit. Higher-order perturbation terms can provide more accurate orbit prediction, especially in long-term orbit evolution and the prediction of high-orbit satellites.

[0048] Atmospheric Drag Model: Atmospheric drag is a significant perturbation factor for low-orbit satellites. The magnitude of atmospheric drag is related to atmospheric density, which varies with factors such as altitude and solar activity. Atmospheric density models are used to estimate atmospheric density and, in turn, calculate the effect of atmospheric drag on satellite orbits.

[0049] Solar Radiation Pressure Model: Solar radiation pressure is the pressure of sunlight on the satellite surface. Its magnitude is related to the satellite's reflective properties and the solar constant. While solar radiation pressure has a minor impact on satellite orbits, it still needs to be considered in long-term orbit predictions.

[0050] For example, in step P100 of the satellite orbit simulation stage, a two-body model can be selected as the satellite orbit model, and factors such as the irregularity of the Earth's gravity field, atmospheric drag, and solar radiation pressure can be taken into account. The motion trajectory of the satellite under the Earth's gravity field is calculated based on the six orbital parameters (semi-major axis, eccentricity, inclination, longitude of ascending node, anomaly, and true anomaly). The J2 and J4 perturbation models are introduced to improve the accuracy of orbit prediction, especially in the prediction of long-term orbital evolution and high-orbit satellites. The position and velocity of the satellite are calculated and updated in real time to reflect its dynamic changes in orbit.

[0051] The use of an accurate force model can improve the accuracy of satellite orbit prediction, thereby providing more accurate satellite position and velocity data for intersatellite link communication simulation and improving the reliability of simulation results.

[0052] In some embodiments, in step P200 of calculating satellite attitude data, quaternions are used to represent the satellite attitude, and the attitude dynamics model takes into account the influence of external interference torques. The external interference torque includes at least one of the gravity gradient torque, the solar radiation pressure torque, and the aerodynamic torque; the inter-satellite distance is calculated based on the position data, and the link delay is calculated based on the inter-satellite distance and the signal propagation speed; the free space propagation loss is calculated based on the inter-satellite distance calculated based on the position data; the antenna pointing deviation is calculated based on the attitude data and the position data, and the preset antenna gain pattern, and the antenna pointing loss is calculated. Accurate satellite attitude is crucial to the establishment of inter-satellite links and the quality of communication. Among them, quaternions are a mathematical tool for representing rotations. Compared with Euler angles, they can avoid the gimbal deadlock problem and provide a more stable attitude description. The attitude dynamics model describes the law of satellite attitude changes over time, which is affected by various torques. External disturbance torques are important factors affecting satellite attitude. These include: gravity gradient torque, which is caused by the uneven distribution of satellite mass and the varying forces exerted by Earth's gravity on different parts of the satellite; solar radiation pressure torque, which is caused by the pressure of sunlight on the satellite surface; and aerodynamic torque, which is caused by the force of atmospheric drag on the satellite surface for low-orbit satellites. Intersatellite distance is calculated based on position data, and link delay is calculated based on the intersatellite distance and signal propagation speed. Link delay calculations provide a reference for subsequent communications. Free space propagation loss is calculated based on the intersatellite distance calculated from position data, providing a reference for subsequent communication link budgets. Antenna pointing loss is calculated based on the antenna pointing deviation calculated from attitude and position data, along with the preset antenna gain pattern, providing a reference for subsequent communication link budgets.

[0053] For example, in step P200 of the satellite attitude simulation phase, Euler angles and quaternions are used to represent the satellite attitude, simulating the satellite's rotation, yaw, pitch, and roll. A satellite attitude dynamics model is applied to describe the change of the satellite attitude over time, taking into account external disturbances such as the earth's gravitational gradient, solar radiation pressure, and atmospheric resistance. The satellite's attitude changes are calculated through numerical integration, and the satellite's attitude is updated in real time.

[0054] Using quaternions to represent satellite attitude and considering the effects of various external disturbance torques can improve the accuracy of satellite attitude simulation, thereby providing more accurate satellite attitude information for intersatellite link communication simulation and improving the reliability of simulation results. At the same time, the influence of various losses is taken into account, improving the accuracy of link simulation.

[0055] In some embodiments, step P300 of calculating key intersatellite link parameters includes: calculating the link bandwidth or data throughput based on the signal bandwidth and modulation order in the preset link parameters; calculating the energy per bit to noise power spectral density ratio (Eb / No) based on the received signal strength and the noise parameter in the preset link parameters; and calculating the bit error rate based on Eb / No and the Gaussian Q function. Accurately calculating key intersatellite link parameters is crucial for evaluating communication link performance.

[0056] Signal bandwidth refers to the frequency range occupied by the signal, and modulation order refers to the order of the modulation scheme, such as QPSK and 16QAM. Link bandwidth or data throughput refers to the amount of data that can be transmitted per unit time and is related to the signal bandwidth and modulation order. Received signal strength refers to the power of the received signal, and noise parameters include noise power spectral density. The ratio of energy per bit to noise power spectral density (Eb / No) is an important indicator of signal quality and is related to received signal strength and noise parameters. The bit error rate (BER) refers to the proportion of bits that experience errors during transmission and is related to Eb / No and the Gaussian Q function. For example, in step S300 of the intersatellite communication link simulation phase, the distance and relative position between satellites are calculated based on satellite orbit and attitude information. The free-space propagation loss formula is used to calculate the signal loss during propagation. The link budget, including parameters such as transmit power, receive power, and noise, is calculated to evaluate the communication quality of the link. The peculiarities of electromagnetic wave propagation in space, such as free-space attenuation, multipath effects, and atmospheric refraction, are considered to calculate key parameters such as link delay, bandwidth, signal strength, and bit error rate. The calculation of the link bandwidth B depends on the signal bandwidth W and the modulation order M, and its mathematical expression is: B = W * log2(M). The calculation of the bit error rate (BER) is based on the energy per bit, the single-sided noise power spectral density, and the Gaussian error function, and its mathematical expression is: BER = Q(sqrt(2*Eb / N0)), where Q(x) = (1 / sqrt(2*pi))*integral(x,inf,exp(-t^2 / 2)dt).

[0057] Through these calculations, we can derive key intersatellite link parameters, providing a basis for evaluating communication link performance. Accurate parameter calculations help predict intersatellite link performance more accurately, providing better guidance for satellite constellation design and operation.

[0058] In some embodiments, the step of performing the three-dimensional visualization display is performed using a game engine. A game engine is a software tool specifically used for game development and real-time 3D rendering. It provides rich graphics rendering, physics simulation, user interface and other functions, and can efficiently create a realistic three-dimensional visualization environment.

[0059] In the present invention, a game engine is used for three-dimensional visualization display, which can present satellite orbits, attitude data and key parameters of intersatellite links in the form of intuitive three-dimensional images, making it convenient for users to observe and analyze. Game engines can include Unreal Engine UE, Unity3D, etc. For example, the visualization and interaction technology module uses Unreal Engine UE in combination with C++ and blueprint language to develop three-dimensional visualization, realizing real-time status display of satellite orbits, attitudes and intersatellite links. UE is selected as the three-dimensional visualization platform, and the blueprint system is closely integrated with the C++ back-end service to achieve a realistic 3D visualization environment. Dynamic visualization technology ensures real-time updates of satellite behavior and communication status, while the data synchronization mechanism ensures real-time exchange of satellite orbits, attitudes and communication data.

[0060] Using a game engine for three-dimensional visualization can improve the visualization of simulation results, allowing users to intuitively understand the operating status of satellite constellations and the performance of inter-satellite communication links, thereby enhancing user experience.

[0061] In some embodiments, the satellite constellation-based inter-satellite link communication simulation method further includes: receiving user interaction instructions, and adjusting preset link parameters or controlling the execution of calculation steps according to the instructions. User interaction instructions refer to instructions issued by the user through the user interface, such as adjusting link parameters such as transmit power, antenna gain, signal frequency, or starting, pausing, and resetting the simulation process. Receiving user interaction instructions and adjusting preset link parameters or controlling the execution of calculation steps according to the instructions can realize real-time control of the simulation process by the user and meet the user's simulation needs for different scenarios. For example, an intuitive user interface is designed, including a dialogue sequence, form layout, and control panel, to facilitate user monitoring and control of the simulation process, provide real-time data display, including satellite orbit parameters, attitude parameters, and key indicators of the inter-satellite link, realize interactive functions, and allow users to control the simulation process through the UI, such as starting, pausing, and resetting the simulation.

[0062] By receiving user interaction instructions and adjusting preset link parameters or controlling the execution of calculation steps according to the instructions, the flexibility and customizability of the simulation can be enhanced to meet the user's needs for different simulation scenarios.

[0063] like Figure 2 As shown, an embodiment of the present invention further provides an inter-satellite link communication simulation system based on a satellite constellation, comprising:

[0064] A satellite orbit simulation unit M100 configured to calculate position and velocity data of at least two satellites in a predetermined time series based on satellite orbit parameters and a force model;

[0065] A satellite attitude simulation unit M200 is configured to calculate attitude data of at least two satellites in a predetermined time series based on satellite attitude parameters and an attitude dynamics model;

[0066] The intersatellite communication link simulation unit M300 is in communication with the satellite orbit simulation unit M100 and the satellite attitude simulation unit M200, and is configured to receive position, velocity, and attitude data, and calculate key parameters of the intersatellite link between at least two satellites based on the received data and preset link parameters, the key parameters including link delay, bandwidth, signal strength, and bit error rate;

[0067] The visualization and interaction unit M400 is connected to the intersatellite communication link simulation unit M300, and is configured to receive position, velocity, attitude data and key parameters of the intersatellite link, and render and display the data in a three-dimensional visualization environment.

[0068] Among them, the satellite orbit simulation unit M100 is responsible for calculating the position and velocity data of the satellite in a predetermined time series, providing satellite orbit information for the simulation of the inter-satellite communication link. It is based on satellite orbit parameters and force models. Satellite orbit parameters are parameters that describe the state of the satellite orbit, such as the six orbital elements. The force model describes the various forces that affect the motion of the satellite, such as the earth's gravity, atmospheric drag, solar radiation pressure, etc. In specific implementation, the orbit simulation unit can use a two-body model as the basis, combined with high-precision six orbital elements, to calculate the motion trajectory of the satellite under the earth's gravitational field. During the simulation process, the irregularities of the earth's gravitational field, atmospheric drag, and solar radiation pressure are taken into account, and the position and velocity of the satellite are calculated and updated in real time to reflect its dynamic changes in orbit.

[0069] The Satellite Attitude Simulation Unit (M200) calculates satellite attitude data over a predetermined time series, providing satellite attitude information for intersatellite communication link simulation and antenna pointing information for subsequent link calculations. It is based on satellite attitude parameters and an attitude dynamics model. Satellite attitude parameters, such as Euler angles and quaternions, describe the satellite's attitude in space. The attitude dynamics model describes how the satellite's attitude changes over time, influenced by various torques such as gravity gradient torque, solar radiation pressure torque, and aerodynamic torque. In practice, the attitude simulation unit accurately simulates satellite attitude control and pointing based on Euler angles and quaternions. Euler angles describe the satellite's rotation relative to the inertial coordinate system, while quaternions are used to avoid gimbal lock. This module simulates the satellite's rotation, yaw, pitch, and roll, as well as its maneuvers and alignment in space.

[0070] The Intersatellite Communication Link Simulator (M300) is responsible for calculating key parameters of the intersatellite communication link, including link latency, bandwidth, signal strength, and bit error rate. It communicates with the Satellite Orbit Simulator (M100) and Satellite Attitude Simulator (M200) modules and is configured to receive position, velocity, and attitude data. Based on this data and preset link parameters, it calculates key parameters of the intersatellite link between at least two satellites. Preset link parameters include transmit power, antenna gain, signal frequency, and modulation method. By monitoring the relative position and attitude of satellites in real time, the M300 calculates the effective transmission path and loss of the link, thereby assessing communication quality. Furthermore, this module takes into account the specific characteristics of electromagnetic wave propagation in the space environment, namely free-space attenuation, multipath effects, and atmospheric refraction.

[0071] The visualization and interaction unit M400 is responsible for displaying satellite orbits, attitude data, and key parameters of intersatellite links in the form of three-dimensional images and providing user interaction functions. It is connected to the intersatellite communication link simulation unit M300 and is configured to receive position, velocity, attitude data, and key parameters of intersatellite links, and render and display the data in a three-dimensional visualization environment. In specific implementation, the visualization and interaction unit M400 can use Unreal Engine UE combined with C++ and Blueprint language for three-dimensional visualization development. UE can efficiently present the real-time status of satellite orbits, attitudes, and intersatellite links. In addition, a user interface is designed, including dialogue sequences and form layouts, to help users easily monitor and control the simulation process.

[0072] By combining these elements, the present invention comprehensively simulates the intersatellite link communication process within a satellite constellation, providing technical support for satellite constellation design, optimization, and performance evaluation. The system's various elements collaborate to achieve joint simulation of satellite orbits, attitudes, and communication links, improving the accuracy and reliability of simulation results and providing users with a more comprehensive understanding of intersatellite communication link performance.

[0073] An embodiment of the present invention also provides a program product for simulating inter-satellite link communications based on a satellite constellation. The program product includes computer instructions that, when executed by a processor, implement the steps of the aforementioned method for simulating inter-satellite link communications based on a satellite constellation. This program product addresses the problems in existing simulation systems, which fail to fully reflect actual communication conditions and accurately simulate the specific characteristics of electromagnetic wave propagation in space environments. It enables comprehensive simulation of satellite orbits, attitudes, and key inter-satellite link parameters, providing a more accurate basis for the design, optimization, and performance evaluation of satellite constellations. Computer instructions refer to instruction sequences executable by a processor and can be assembly instructions, machine instructions, or instructions compiled from a high-level language. A program product refers to a storage medium containing computer instructions, such as an optical disc, magnetic disk, or flash drive, or a computer instruction file transmitted over a network. For example, the program product may include the following modules: a satellite orbit simulation module, a satellite attitude simulation module, an inter-satellite communication link simulation module, a visualization and interaction module, and a data interaction and system testing module. Users can install the program product on a computer and operate it through a user interface to simulate inter-satellite link communications within a satellite constellation.

[0074] By providing a program product containing computer instructions, users can conveniently deploy and run the simulation method of the present invention on various computing platforms, providing a convenient tool for the design, optimization and performance evaluation of satellite constellations.

[0075] like Figure 3 As shown, the embodiment of the present invention also provides another implementation of an inter-satellite link communication simulation system and method based on a satellite constellation.

[0076] This embodiment provides a visualization system and platform for calculating key intersatellite link indicators and parameters in real time based on a simulated constellation, enabling simulation of multiple satellite orbits, attitude, and communication links. This constellation-based intersatellite communication link simulation system, implemented using Unreal Engine combined with C++ and Blueprint technology, offers stable performance and reliable 3D visualization and digital simulation of constellations and celestial bodies, providing a precise research platform for today's rapid satellite development.

[0077] In the specific implementation, the satellite's motion trajectory in the Earth's gravitational field is calculated based on the two-body model and the six orbital elements. Specifically, in the standard J2000 geocentric inertial coordinate system, the satellite acceleration is defined by the mathematical expression The orbital state is described using six orbital numbers, including eccentricity e, inclination i, longitude of ascending node Ω, semi-major axis a, argument of perihelion ω, and true anomaly f. The true anomaly is calculated using the Kepler equation M = Ee sin(E), where M is the mean anomaly and E is the eccentric anomaly, and the conversion formula. Then use the elliptical orbit equation to calculate the satellite position In order to improve the accuracy, it is preferred to introduce the J2 and J4 perturbation models as part of the standard Earth gravity field model such as EGM96 to consider the impact of the Earth's non-spherical shape on the orbit; at the same time, introduce a standard atmospheric density model such as NRLMSISE-00, combined with the satellite's ballistic coefficient, to calculate the atmospheric drag perturbation; and take into account the solar radiation pressure perturbation, which is calculated based on the optical properties of the satellite surface, the effective area, and the sunshine conditions (considering the earth's shadow). The equations of motion containing these perturbation terms are solved by a high-order numerical integrator such as the Runge-Kutta RK4 / 5 method to provide more accurate orbit predictions than the pure two-body model. Calculate the satellite velocity using Kepler's second law and Newton's laws of motion, that is,

[0078] Then, the satellite attitude simulation module is based on the Euler angle and quaternion theory, and preferably uses quaternions to represent the satellite attitude to avoid the gimbal deadlock problem in the Euler angle representation and ensure the continuity of the attitude description. and Accurately simulate the attitude control and pointing of the satellite. The specific steps include using Euler angles to describe the satellite's rotation angle relative to the inertial coordinate system, and using quaternions to avoid the gimbal deadlock problem. The dynamic equations of Euler angles and quaternions are used to simulate the satellite's rotation, yaw, pitch and roll in space. In addition, we also combine the impact of external disturbances on the satellite's attitude to specifically model and calculate the main interference torques, including the gravity gradient torque calculated based on the satellite's inertia tensor and position, the solar radiation pressure torque calculated based on the satellite's surface characteristics and sunlight direction, and the aerodynamic torque calculated based on the atmospheric density and satellite shape for low-orbit satellites. The changes in satellite attitude are calculated through numerical integration.

[0079] Subsequently, the intersatellite communication link simulation module is responsible for calculating the key parameters of intersatellite communication, including link delay, bandwidth, signal strength and bit error rate, and calculating the distance between any two satellites based on the position information provided by the satellite orbit simulation module. Calculate signal propagation loss using the free space propagation loss formula The link budget comprehensively considers the transmit power P_t, transmit / receive antenna gain G_t / G_r, well-defined system loss L (such as feeder and connector loss), free space loss L_f, and the key antenna pointing loss L_pointing to calculate the received power P r =P t +G t +G r -LL f, calculate the signal transmission delay based on the inter-satellite distance and signal propagation speed, calculate the link bandwidth B = W·log2(M) based on the signal bandwidth and modulation order, and finally calculate the bit error rate based on the energy per bit, the single-sided noise power spectral density and the Gaussian error function in, All these parameters are displayed through the 3D visualization tool Unreal Engine to intuitively understand the communication status.

[0080] Next, the visualization and interaction technology module used Unreal Engine UE combined with C++ and Blueprint language to develop three-dimensional visualization, realizing the real-time status display of satellite orbits, attitudes and intersatellite links. UE was selected as the three-dimensional visualization platform, and the blueprint system was closely integrated with the C++ back-end service to achieve a realistic 3D visualization environment. Dynamic visualization technology ensured real-time updates of satellite behavior and communication status, while the data synchronization mechanism ensured real-time exchange of satellite orbits, attitudes and communication data. An intuitive user interface was designed, including form layouts for parameter settings, dashboards and charts for status monitoring, and buttons and dialogue sequences for process control, to facilitate users to monitor and control the simulation process.

[0081] Finally, the data interaction and system testing module designed the data interface between modules (for example, through API or shared memory mechanism), realized data exchange between different modules, and supported dynamic updating of visual content. During the performance testing and optimization phase, key indicators such as rendering efficiency, frame rate and response time were evaluated, and system optimization was carried out accordingly. In addition, detailed user manuals and operation guides were written, system integration testing was carried out, and technical support and maintenance services were provided. During the testing phase, white-box testing and black-box testing methods were adopted. Through carefully designed test cases, the correctness and performance of satellite orbit, attitude and communication functions were comprehensively tested to ensure the stability and reliability of the system.

[0082] In summary, the various modules of the inter-satellite link communication simulation design based on the satellite constellation in this embodiment, from orbit and attitude simulation to communication link calculation, and then to visualization and system testing, constitute a complete simulation system aimed at comprehensively simulating the behavior and performance of the satellite constellation.

[0083] Another aspect of this embodiment provides a visualization method for calculating key indicators and parameters of real-time inter-satellite links based on a simulated constellation, realizing orbit simulation, attitude simulation, and communication link simulation of multiple satellites around the Earth. This method not only simulates the orbit and attitude of the satellite, but also deeply simulates the key parameters of the inter-satellite communication link, such as link delay, bandwidth, signal strength, and bit error rate. By introducing high-precision six orbital numbers and considering the irregularities of the Earth's gravity field (using a high-order gravity field model), atmospheric drag (using a standard atmosphere model), solar radiation pressure (taking into account satellite characteristics and illumination), and other influencing factors, this method can calculate and update the satellite's position and velocity in real time, and accurately calculate the antenna pointing in combination with the attitude simulation results, thereby achieving high-precision prediction of the satellite's orbit and attitude.

[0084] First, enter the satellite orbit simulation stage S100, select the two-body model as the satellite orbit model, consider the irregularities of the Earth's gravity field, adopt factors such as the J2, J4 terms or higher-order terms of the EGM96 model, atmospheric drag (based on models such as NRLMSISE-00 and ballistic coefficients), solar radiation pressure (based on surface optical properties and sunshine models), etc., calculate the motion trajectory of the satellite in the Earth's gravity field based on the six orbital parameters (semi-major axis, eccentricity, inclination, longitude of ascending node, anomaly, true anomaly), introduce J2 and J4 perturbation models to improve the accuracy of orbit prediction, especially in the prediction of long-term orbit evolution and high-orbit satellites, calculate and update the satellite's position and velocity in real time to reflect its dynamic changes in orbit.

[0085] Then, the satellite attitude simulation stage S200 is entered. Euler angles and quaternions are used to represent the satellite attitude. The satellite's rotation, yaw, pitch and roll are simulated. Satellite attitude dynamics (based on the Euler equation or equivalent quaternion kinematic equations) are applied to describe the change of satellite attitude over time. External disturbances such as the earth's gravitational gradient, solar radiation pressure, and atmospheric resistance are considered for specific torque modeling. The satellite's attitude changes are calculated through numerical integration, and the satellite's attitude is updated in real time.

[0086] Next, we enter the inter-satellite communication link simulation phase S300. Based on the satellite orbit and attitude information, we calculate the distance and relative position between the satellites. We use the free space propagation loss formula to calculate the signal loss during propagation, and calculate the link budget, including the transmit power, antenna gain, system loss, FSPL, and antenna pointing loss calculated based on real-time attitude and relative position, to obtain the received power. The communication quality of the link is evaluated. Free space attenuation is taken into account, and based on the link characteristics, it is determined whether the model needs to be simplified to account for multipath effects (such as the Rician model) and atmospheric refraction (usually ignored in ISL). Key parameters such as link delay (based on distance), bandwidth (based on settings), signal strength (based on link budget), and bit error rate (based on Eb / No and Q function) are calculated.

[0087] Next, we enter the visualization and interaction technology stage S400, using Unreal Engine UE, C++, and Blueprint language for 3D visualization development, leveraging its real-time rendering and physical simulation capabilities to display the real-time status of satellite orbits, attitudes, and intersatellite links. We design a user interface, including dialogue sequences, form layouts, and control panels, to facilitate users to monitor and control the simulation process, provide real-time data display, including satellite orbit parameters, attitude parameters, and key indicators of intersatellite links, implement interactive functions, and allow users to control the simulation process through the UI, such as starting, pausing, resetting the simulation, and adjusting key simulation parameters.

[0088] Finally, we enter the data interaction and system testing phase S500, designing the front-end and back-end interaction mechanisms to ensure that data can be smoothly exchanged between the client and the server. We develop API interfaces to allow external systems to access and control the system, implement data input and output, and automate testing. We conduct system testing, including white-box and black-box testing, to comprehensively verify the correctness and performance of the satellite's orbit, attitude, and communication functions. We also conduct performance testing to evaluate the response time and resource consumption of the simulation system under different load conditions.

[0089] Through the above embodiments, the present invention provides a satellite constellation-based inter-satellite link communication simulation design and implementation method, which can calculate the key indicators of the inter-satellite link in real time and realize three-dimensional visual simulation of satellite orbits, attitudes and communication links. This method has the advantages of high simulation accuracy, good reliability, good visualization effect and strong user interactivity, and can effectively improve the performance and efficiency of the inter-satellite communication system.

[0090] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A satellite constellation-based inter-satellite link communication simulation method, characterized in that: The following steps are involved: Calculate the position and velocity data of at least two satellites in a predetermined time series based on satellite orbit parameters and a force model; Calculating attitude data of the at least two satellites in the predetermined time series based on satellite attitude parameters and an attitude dynamics model; Calculating key parameters of an intersatellite link between the at least two satellites based on the position data, the velocity data, the attitude data, and preset link parameters, the key parameters including link delay, bandwidth, signal strength, and bit error rate; The position data, the speed data, the attitude data and the key parameters of the intersatellite link are displayed in a three-dimensional visual manner.

2. The method for automatically generating business trip invention forms according to claim 1, characterized in that: The force model includes at least one of an earth non-spherical gravity model, an atmospheric resistance model and a solar radiation pressure model.

3. The method for automatically generating business trip invention forms according to claim 2, characterized in that: The non-spherical gravity model of the Earth includes at least J2 and J4 perturbation terms.

4. The method for automatically generating business trip invention forms according to claim 2, characterized in that: The atmospheric resistance model calculates the atmospheric resistance perturbation based on the atmospheric density model, and the solar radiation pressure model calculates the solar radiation pressure perturbation based on the satellite reflection characteristics and the solar constant.

5. The method for automatically generating business trip invention forms according to claim 1, characterized in that: In the step of calculating the attitude data of the at least two satellites in the predetermined time series, quaternions are used to represent the satellite attitudes, and the attitude dynamics model is implemented based on external interference torques, and the external interference torques include at least one of gravity gradient torques, solar radiation pressure torques and aerodynamic torques.

6. The method for automatically generating business trip invention forms according to claim 1, characterized in that: The step of calculating the key parameters of the inter-satellite link includes: calculating the inter-satellite distance based on the position data, and calculating the link delay based on the inter-satellite distance and signal propagation speed.

7. The method for automatically generating business trip invention forms according to claim 1, characterized in that: The step of calculating the key parameters of the intersatellite link includes: calculating the signal strength based on the transmit power, antenna gain, and system loss in the preset link parameters, and in combination with the free space propagation loss and / or the antenna pointing loss.

8. The method for automatically generating business trip invention forms according to claim 1, characterized in that: The step of calculating the key parameters of the intersatellite link includes: calculating the ratio of energy per bit to noise power spectrum density based on the signal strength and the noise parameter in the preset link parameters, and calculating the bit error rate based on the density ratio and a Gaussian Q function.

9. A satellite constellation-based inter-satellite link communication simulation system, configured to implement the steps of the satellite constellation-based inter-satellite link communication simulation method according to any one of claims 1 to 8, comprising: a satellite orbit simulation unit configured to calculate position data and velocity data of at least two satellites in a predetermined time series based on the satellite orbit parameters and the force model; a satellite attitude simulation unit configured to calculate attitude data of at least two satellites in a predetermined time series based on satellite attitude parameters and an attitude dynamics model; an intersatellite communication link simulation unit, communicatively connected to the satellite orbit simulation unit and the satellite attitude simulation unit, configured to receive the position data, the velocity data, and the attitude data, and calculate key parameters of the intersatellite link between at least two satellites based on the received data and preset link parameters, the key parameters including link delay, bandwidth, signal strength, and bit error rate; The visualization and interaction unit is communicatively connected to the intersatellite communication link simulation unit and is configured to receive position data, velocity data, attitude data and key parameters of the intersatellite link, and render and display the data in a three-dimensional visualization environment.

10. A satellite constellation-based inter-satellite link communication simulation program product, the program product comprising computer instructions, which, when executed by a processor, implement the steps of the satellite constellation-based inter-satellite link communication simulation method according to any one of claims 1 to 8.

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