Intersatellite link communication simulation system and method based on satellite constellation

Abstract

The invention relates to an inter-satellite link communication simulation system and method based on a satellite constellation. The system comprises a satellite orbit simulation module, a satellite attitude simulation module, an inter-satellite communication link simulation module, a visualization and interaction technology module and a data interaction and system test module. The satellite orbit simulation module is used for calculating a movement track of a satellite in an earth gravitational field; the satellite attitude simulation module is used for accurately simulating a satellite attitude; the inter-satellite communication link simulation module is used for evaluating inter-satellite communication quality; the visualization and interaction technology module is used for presenting real-time states of satellite orbits, attitudes and inter-satellite links; and the data interaction and system test module is used for smoothly exchanging data, and comprehensively testing and checking the correctness and performance of satellite orbits, attitudes and communication functions. The method has the beneficial effects that the real-time states of the satellite orbit, the attitude and the inter-satellite link are efficiently presented, so that a user can easily monitor and control the simulation process.

Description

[Technical field]

[0001] The present invention relates to the field of satellite aerospace technology, and in particular to an inter-satellite link communication simulation system and method based on a satellite constellation. [Background technology]

[0002] With the acceleration of the global informatization process, satellite communication technology is developing at an unprecedented speed, especially the concept of satellite constellations has been widely used in many fields, namely global navigation and positioning, remote sensing monitoring, and broadband Internet access. In recent years, with the advancement of technology and the reduction of costs, the deployment of small satellites and microsatellites has become more and more common, and the scale of satellite constellations has continued to expand. This trend has spawned new application scenarios, such as the integrated air-space-ground network, which aims to seamlessly integrate satellite communications with ground communication networks to form a high-speed and stable information transmission network covering the world. In this context, the design and operation of satellite constellations face unprecedented challenges, especially how to achieve efficient and stable communications in inter-satellite networks to meet the growing demand for data transmission.

[0003] Although satellite constellation technology has made significant progress, it still faces many challenges in its actual deployment and application. In particular, in the space-based edge computing scenario, the collaborative work of multiple satellites is highly dependent on inter-satellite communications, and the existing simulation systems have obvious deficiencies in this area. On the one hand, most simulation systems focus on the single simulation of satellite orbits and attitudes, ignoring the complexity and dynamics of inter-satellite communication links, resulting in the simulation results being unable to fully reflect the actual communication conditions. On the other hand, even if some systems try to add communication link simulation, it is often difficult to accurately simulate the particularities of electromagnetic wave propagation in the space environment (i.e., free space attenuation, multipath effects, and atmospheric refraction), as well as the profound impact of these factors on communication quality, due to model simplification and unreasonable parameter settings. It is also difficult to provide intuitive and convenient monitoring and control methods, which limits the in-depth analysis and optimization of satellite constellation performance by scientific researchers.

[0004] To summarize, in order to meet the growing demand for satellite services, the present invention aims to solve the technical problem that the existing inter-satellite link communication simulation focuses on the single simulation of satellite orbit and attitude, ignores the complexity and dynamics of the inter-satellite communication link, and limits the in-depth analysis and optimization of satellite constellation performance by scientific researchers. The invention makes technical improvements to the inter-satellite communication link simulation model and implementation method, so as to comprehensively simulate the satellite's orbit, attitude and communication link, study and optimize the performance of the inter-satellite communication system, and improve its reliability and efficiency in practical applications. [Summary of the invention]

[0005] The purpose of the present invention is to provide an intersatellite link communication simulation system which can efficiently present the real-time status of satellite orbit, attitude and intersatellite link, so that users can easily monitor and control the simulation process.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is an inter-satellite link communication simulation system based on a satellite constellation, including a satellite orbit simulation module, a satellite attitude simulation module, an inter-satellite communication link simulation module, a visualization and interaction technology module, and a data interaction and system testing module;

[0007] The satellite orbit simulation module is used to calculate the motion trajectory of the satellite under the earth's gravitational field;

[0008] The satellite attitude simulation module is used to accurately simulate the satellite's rotation, yaw, pitch and roll attitude, as well as the satellite's maneuvering and aiming process in space;

[0009] The intersatellite communication link simulation module is used to calculate the effective transmission path and loss of the intersatellite communication link, and then evaluate the intersatellite communication quality;

[0010] The visualization and interaction technology module is used to intuitively display the dynamic behavior and communication status of the satellite constellation, and efficiently present the real-time status of the satellite orbit, attitude and inter-satellite link;

[0011] The data interaction and system testing module is used for smooth data exchange and comprehensive testing and verification of the correctness and performance of satellite orbit, attitude and communication functions.

[0012] Another object of the present invention is to provide an intersatellite link communication simulation method that efficiently presents satellite orbits, attitudes and real-time status of intersatellite links, allowing users to easily monitor and control the simulation process.

[0013] To achieve the above-mentioned further object, the technical solution adopted by the present invention is a satellite constellation-based inter-satellite link communication simulation method, based on the above-mentioned satellite constellation-based inter-satellite link communication simulation system, comprising the following steps:

[0014] S100, satellite orbit simulation: The satellite orbit simulation module uses a two-body model as a basis, combined with high-precision orbit six elements, to calculate the motion trajectory of the satellite under the earth's gravitational field. During the simulation process, the influence factors of the irregularity of the earth's gravitational field, atmospheric resistance, and solar radiation pressure are considered, and the position and speed of the satellite are calculated and updated in real time to reflect the dynamic changes of the satellite in orbit;

[0015] S200, satellite attitude simulation: The satellite attitude simulation module is based on Euler angle and quaternion theory to accurately simulate the attitude control and pointing of the satellite. The Euler angle is used to describe the rotation angle of the satellite relative to the inertial coordinate system, while the quaternion is used to avoid the "universal joint deadlock" problem, simulating the rotation, yaw, pitch and roll of the satellite, as well as the process of the satellite maneuvering and aligning to the target in space;

[0016] S300, intersatellite communication link simulation: the intersatellite communication link simulation module calculates key parameters of intersatellite communication, including link delay, bandwidth, signal strength and bit error rate, calculates the effective transmission path and loss of the link by real-time monitoring the relative position and attitude between satellites, and then evaluates the communication quality. In addition, the intersatellite communication link simulation module also considers the particularity of electromagnetic wave propagation in the space environment, namely free space attenuation, multipath effect and atmospheric refraction;

[0017] S400, visualization and interaction technology: The visualization and interaction technology module intuitively displays the dynamic behavior and communication status of the satellite constellation. It uses Unreal Engine UE combined with C++ and Blueprint language for three-dimensional visualization development, and can efficiently present the real-time status of satellite orbits, attitudes and intersatellite links. In addition, the visualization and interaction technology module also designs the user interface, including dialogue sequences and form layouts, to help users easily monitor and control the simulation process;

[0018] S500, data interaction and system testing: The design of the front-end and back-end interaction of the data interaction and system testing module enables smooth data exchange, and the API interface interaction design provides seamless connection with external systems. The data interaction and system testing module adopts white box testing method in the testing phase, and comprehensively verifies the correctness and performance of satellite orbit, attitude and communication functions through carefully designed test cases.

[0019] Preferably, step S100 specifically includes the following sub-steps:

[0020] S110. Definition of six orbital elements: six orbital elements are six basic parameters describing the state of satellite orbits, including the size of the semi-major axis a of the elliptical orbit, the eccentricity e of the orbital shape, the inclination angle i between the orbital plane and the reference plane, the longitude of the ascending node Ω where the orbital plane intersects the reference plane, the anomaly ω from the ascending node to the perigee, the true anomaly v and the mean anomaly M describing the position of the satellite on the orbit;

[0021] S120. Conversion between mean anomaly and true anomaly: The mean anomaly M and true anomaly v reflect the average position and true position of the satellite in orbit. The conversion relationship between them is given by the Kepler equation: M = E-esin(E), where E is the eccentric anomaly.

[0022] S130. Introduction of perturbation model: For higher-precision orbit prediction, the J2 perturbation model is introduced to consider the impact of the non-spherical shape of the earth on the orbit. For long-term orbital evolution and orbit prediction of high-orbit satellites, the J4 perturbation model is introduced to further consider higher-order terms of the earth's shape and provide more accurate orbit predictions.

[0023] Preferably, step S100 specifically further includes the following sub-steps:

[0024] S101, calculation of satellite position and velocity, i.e. determination of six orbital elements and true anomaly, calculation of satellite position and velocity using Kepler equations and Newton's laws of motion;

[0025] Calculate the true anomaly: Given the eccentric anomaly E, use the conversion formula, i.e.

[0026] Calculate the satellite position: Use the elliptical orbit equation to calculate the satellite's position in the orbital plane, that is, r is the distance from the satellite to the central body;

[0027] Calculate satellite velocity: Use Kepler's second law and Newton's laws of motion to calculate the velocity, i.e.

[0028] Preferably, step S200 specifically includes the following sub-steps:

[0029] S210, Satellite attitude representation: Satellite attitude is represented by Euler angles and quaternions. Euler angles describe the position of the satellite relative to a fixed reference coordinate system through three consecutive rotation angles, while quaternions provide a representation method to avoid gimbal deadlock.

[0030] S220, Applied Satellite Attitude Dynamics: Describes the change of satellite attitude over time. In the absence of external torque, the satellite attitude will remain unchanged. Due to external disturbances, i.e., the Earth's gravitational gradient, solar radiation pressure, and atmospheric drag, the satellite attitude will change;

[0031] S230, Dynamic equation of Euler angle: For Euler angle, the posture dynamics is expressed as: φ, θ, ψ are Euler angles, I x ,I y ,I z is the moment of inertia of the satellite's main axis, M x 、M y 、M z is the external torque exerted on the satellite;

[0032] S40, Quaternion dynamics equation: For quaternion, the rotation representing the attitude change, the attitude dynamics is expressed as: Ω(q) is a matrix associated with the quaternion q, M is the external moment vector;

[0033] S250, attitude simulation calculation: Based on the Euler angle, quaternion attitude representation method and dynamic equations, numerical integration is performed to calculate the satellite's attitude changes.

[0034] Preferably, step S300 specifically includes the following sub-steps:

[0035] S310, calculate the distance between satellites: calculate the distance between any two satellites according to the satellite position information provided by the satellite orbit simulation module (x1, y1, z1) and (x2, y2, z2) are the position coordinates of the two satellites respectively;

[0036] S320, Calculate free space propagation loss: Use the free space propagation loss formula to calculate the signal loss L during propagation. f ,Right now d is the distance between satellites, λ is the wavelength of the signal;

[0037] S330, calculate link budget: The link budget includes parameters of transmit power, receive power, and noise. Calculate receive power P r , that is, P r =P t +G t +G r -LL f , P t is the transmit power, G t is the transmit antenna gain, G r is the receiving antenna gain, L is the system loss, and L f is the free space loss;

[0038] S340, calculate the signal transmission delay: the signal transmission delay is determined by the inter-satellite distance d and the signal propagation speed v, that is,

[0039] S350, calculating the link bandwidth: 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);

[0040] S360, calculate the bit error rate: the bit error rate BER is calculated based on the energy per bit E b , unilateral noise power spectrum density N0 and Gaussian error function Q(x), whose mathematical expressions are: in,

[0041] Preferably, step S400 specifically includes the following sub-steps:

[0042] S410, Visualization Design and Implementation: Unreal Engine UE is selected as the 3D visualization platform, and the blueprint system is used to closely integrate with C++ backend services to achieve a highly realistic 3D visualization environment;

[0043] S420, Dynamic Visualization: Through the real-time rendering technology of UE, the real-time status of satellite orbit, attitude and intersatellite link is dynamically displayed. The physics engine of UE is used to simulate various mechanical phenomena of satellite in space environment, making the visualization effect closer to reality.

[0044] S430, data synchronization: through the interaction between the C++ backend and the UE front end, the satellite orbit, attitude and communication data are updated in real time;

[0045] S440, Interaction Design and Implementation: Design intuitive user interfaces, including dialogue sequences, form layouts, and control panels, to ensure that users can easily monitor and control the simulation process; use UE's UMG system to create user interface elements to support data presentation in the form of charts and dashboards;

[0046] S450, interactive logic development: Utilize the UE's blueprint system to encapsulate complex logic and interactions into visual nodes, call backend data and functions through the blueprint language, and realize dynamic update of satellite trajectory attitude visualization and intersatellite communication link visualization.

[0047] Preferably, step S500 specifically includes the following sub-steps:

[0048] S510, data interface and interaction implementation: Develop data interface to realize data exchange between visualization module and satellite orbit simulation module, satellite attitude simulation module and intersatellite communication link simulation module, and support dynamic update of visualization content during simulation;

[0049] S520, Deployment and Maintenance: Deploy the visualization and interaction technology modules to the target platform, conduct system integration testing, and provide technical support and maintenance services, including software updates, troubleshooting, and user feedback processing.

[0050] Preferably, the data interaction and system testing module tests the performance including the following steps:

[0051] Test case design: Based on simulation requirements, design test cases covering the functions and performance of each module, including normal operation, abnormal conditions and boundary conditions;

[0052] Test environment construction: configure the test environment, including hardware resources, software environment and test tools, to ensure the stability and reliability of the test environment;

[0053] Automated testing: Use automated testing tools and methods to execute test cases, collect test results, and perform automatic analysis and evaluation;

[0054] White box testing: white box testing is performed on key modules of satellite orbit simulation module, satellite attitude simulation module, and intersatellite communication link simulation module to check code logic, algorithm implementation, and internal data structure;

[0055] Black box testing: Perform black box testing on the entire simulation system to verify whether the system functions and performance meet the requirements specifications;

[0056] Problem tracking and repair: Record problems found during testing, track the repair of problems, and perform regression testing to ensure that problems are completely resolved.

[0057] Preferably, the data interaction and system testing module further comprises the following steps of testing the performance:

[0058] Load testing: simulate high load conditions to test the performance and stability of the system under large amounts of data processing;

[0059] Stress testing: Testing the system's performance under extreme conditions to prevent system crashes and data loss;

[0060] Boundary condition testing: Testing the system's performance under boundary conditions, i.e., extremely low and high orbits, and satellite-dense areas;

[0061] Exception handling testing: Verify the system's ability to handle errors and abnormal data, and help the system respond and recover correctly;

[0062] User interface testing: Testing the usability and functionality of the user interface to ensure that users can intuitively understand and operate the system;

[0063] Real-time data testing: testing the system in a real environment to ensure the accuracy and timeliness of real-time data;

[0064] User Acceptance Testing: Conduct user acceptance testing to let end users test the simulation system, collect user feedback, and adjust and optimize the system based on user feedback.

[0065] The present invention provides a satellite constellation-based intersatellite link communication simulation method and device with the following beneficial effects: it can calculate intersatellite link key indicators in real time, realize three-dimensional visualization simulation of satellite orbit, attitude and communication link, and 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 intersatellite communication system;

[0066] First, by establishing an inter-satellite communication link simulation model, the key indicators of the inter-satellite link, namely link delay, bandwidth, signal strength and bit error rate, can be calculated in real time. This real-time simulation capability allows researchers and engineers to predict the performance of the communication link before the actual launch of the satellite, thereby optimizing the design and operation of the satellite network; in addition, by considering the irregularities of the earth's gravity field, atmospheric drag, and solar radiation pressure, more accurate satellite orbit predictions can be provided, thereby enhancing the reliability of the inter-satellite communication link.

[0067] 2. Using Unreal Engine UE in combination with C++ and Blueprint language for 3D visualization development can intuitively display the dynamic behavior and communication status of satellite constellations. Its 3D visualization provides richer and more intuitive information, which helps users better understand the real-time status of satellite orbits, attitudes, and intersatellite links. In addition, the designed user interface, including dialogue sequences and form layouts, enables users to easily monitor and control the simulation process, improving the user-friendliness and ease of operation of the system.

Brief Description of the Drawings

[0068] Figure 1 It is an operational flow chart of the simulation design of inter-satellite link communication based on satellite constellation.

[0069] Figure 2 It is a flow chart of the implementation method of inter-satellite link communication simulation design based on satellite constellation. [Specific implementation method]

[0070] The present invention will be further described below in conjunction with embodiments and with reference to the accompanying drawings.

[0071] Example 1

[0072] This embodiment implements a satellite constellation-based inter-satellite link communication simulation design and implementation method.

[0073] This embodiment can perform three-dimensional visualization development by using Unreal Engine UE in combination with C++ and Blueprint language, and can efficiently present the real-time status of satellite orbits, attitudes, and intersatellite links. A user interface is designed, including dialogue sequences and form layouts, so that users can easily monitor and control the simulation process.

[0074] Figure 1 This is an operational flow chart of the inter-satellite link communication simulation design based on the satellite constellation. Figure 1 As shown, this embodiment provides the following technical solutions: on the one hand, an inter-satellite link communication simulation design based on a satellite constellation, the components of which include: a satellite orbit simulation module, a satellite attitude simulation module, an inter-satellite communication link simulation module, a visualization and interaction technology module, and a data interaction and system testing module.

[0075] The satellite orbit simulation module is based on a two-body model and combines high-precision orbital six elements to calculate the motion trajectory of the satellite under the earth's gravitational field. During the simulation process, the irregularity of the earth's gravitational field, atmospheric resistance, and solar radiation pressure are considered to calculate and update the satellite's position and speed in real time to reflect its dynamic changes in orbit.

[0076] The satellite attitude simulation module is based on Euler angle and quaternion theory to accurately simulate the attitude control and pointing of the satellite. Euler angle is used to describe the rotation angle of the satellite relative to the inertial coordinate system, while quaternion is used to avoid the "gimbal deadlock" problem. This module simulates the satellite's rotation, yaw, pitch and roll, as well as the process of the satellite maneuvering and aligning to the target in space.

[0077] 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. By monitoring the relative position and attitude between satellites in real time, the effective transmission path and loss of the link are calculated, and the communication quality is evaluated. In addition, the module also takes into account the particularity of electromagnetic wave propagation in the space environment, namely free space attenuation, multipath effect and atmospheric refraction.

[0078] The visualization and interaction technology module intuitively displays the dynamic behavior and communication status of the satellite constellation. It uses 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.

[0079] The design of data interaction and front-end and back-end interaction of the system test module enables smooth data exchange, and the API interface interaction design provides seamless connection with external systems. The white box testing method is adopted in the testing phase. Through carefully designed test cases, the correctness and performance of the satellite orbit, attitude and communication functions are comprehensively tested.

[0080] Furthermore, the satellite orbit simulation module is used to predict and analyze the movement of the satellite in its orbit, and its specific simulation steps are:

[0081] Selecting a satellite orbit model: The satellite orbit model depends on the required accuracy and computing resources. The two-body model is the most basic and is suitable for the preliminary design and analysis of low-Earth orbit satellites. In the two-body model, the satellite is only affected by the Earth's gravity and the influence of other forces is ignored.

[0082] Define the mathematical expression of the two-body model: In the two-body model, the satellite and the earth are the only two interacting objects. The earth is regarded as a point mass, and the satellite's motion trajectory is regarded as an ellipse and is only affected by the earth's gravity. That is, the mathematical expression is: a sat is the acceleration of the satellite, μ is the gravitational constant of the Earth, r is the distance from the satellite to the center of the Earth, and r is the position vector pointing from the center of the Earth to the satellite;

[0083] Definition of six orbital numbers: six orbital numbers are six basic parameters that describe the state of a satellite orbit, including: semi-major axis a is the size of the elliptical orbit, eccentricity e is the shape of the orbit, inclination i is the inclination angle between the orbital plane and the reference plane, ascending node longitude Ω is the position of the intersection of the orbital plane and the reference plane, anomaly ω is the angle from the ascending node to the perigee, true anomaly v and mean anomaly M describe the position of the satellite in orbit;

[0084] Conversion between mean anomaly and true anomaly: The mean anomaly M and true anomaly v reflect the average position and true position of the satellite in orbit. The conversion relationship between them is given by the Kepler equation: M = E-esin(E), where E is the eccentric anomaly;

[0085] Introduction of perturbation model: For higher-precision orbit prediction, the J2 perturbation model is introduced to consider the impact of the non-spherical shape of the Earth on the orbit. The J4 perturbation model further considers higher-order terms of the Earth's shape to provide more accurate orbit predictions, especially in the prediction of long-term orbital evolution and high-orbit satellites.

[0086] Furthermore, the satellite orbit simulation module also includes the calculation of satellite position and velocity, that is, determining the six orbit elements and the true anomaly, and using Kepler's equations and Newton's laws of motion to calculate the satellite's position and velocity. The specific simulation steps are as follows:

[0087] Calculate the true anomaly: Given the eccentric anomaly E, use the conversion formula, i.e.

[0088] Calculate the satellite position: Use the elliptical orbit equation to calculate the satellite's position in the orbital plane, that is, r is the distance from the satellite to the central body;

[0089] Calculate satellite velocity: Use Kepler's second law and Newton's laws of motion to calculate the velocity, i.e.

[0090] Orbit visualization and analysis: The 3D visualization tool Unreal Engine is used to display simulation results of satellite orbits, helping to understand and analyze orbital characteristics.

[0091] Furthermore, the satellite attitude simulation module is responsible for simulating the orientation and control of the satellite in space, ensuring that the satellite can correctly align with the earth and other targets, and accurately simulating the attitude changes of the satellite in space. The specific simulation steps are:

[0092] Satellite attitude representation: Satellite attitude is represented by Euler angles and quaternions. Euler angles describe the position of the satellite relative to a fixed reference coordinate system through three consecutive rotation angles, while quaternions provide a representation method to avoid gimbal deadlock.

[0093] Application of satellite attitude dynamics: describes the change of satellite attitude over time. In the absence of external torque, the satellite attitude will remain unchanged. Due to external disturbances, i.e., the earth's gravitational gradient, solar radiation pressure, and atmospheric drag, the satellite attitude will change;

[0094] Dynamic equation of Euler angle: For Euler angle, the posture dynamics is expressed as: φ, θ, ψ are Euler angles, I x ,I y ,I z is the moment of inertia of the satellite's main axis, M x 、M y 、M z is the external torque exerted on the satellite;

[0095] Quaternion dynamics equation: For quaternion, the rotation representing the attitude change, the attitude dynamics is expressed as: Ω(q) is a matrix associated with the quaternion q, M is the external moment vector;

[0096] Attitude simulation calculation: Based on Euler angles, quaternion attitude representation method and dynamic equations, numerical integration is performed to calculate the satellite's attitude changes;

[0097] Attitude visualization and analysis: The 3D visualization tool Unreal Engine is used to display the simulation results of satellite orbit and attitude, helping to understand and analyze attitude characteristics.

[0098] Furthermore, the intersatellite communication link simulation module is used to calculate the key parameters of intersatellite communication, including link delay, bandwidth, signal strength and bit error rate. By monitoring the relative position and attitude between satellites in real time, the effective transmission path and loss of the link are calculated, and the communication quality is evaluated. The simulation process is as follows:

[0099] Intersatellite distance: Calculate the distance between any two satellites based on the satellite position information provided by the satellite orbit simulation module (x1, y1, z1) and (x2, y2, z2) are the position coordinates of the two satellites respectively;

[0100] Calculate free space propagation loss: Use the free space propagation loss formula to calculate the signal loss L during propagation. f ,Right now d is the distance between satellites, λ is the wavelength of the signal;

[0101] Calculate link budget: The link budget includes the parameters of transmit power, receive power, and noise. Calculate the receive power P r , that is, P r =P t +G t +G r -LL f , P t is the transmit power, G t is the transmit antenna gain, G r is the receiving antenna gain, L is the system loss, and L f is the free space loss;

[0102] Calculate the signal transmission delay: The signal transmission delay is determined by the inter-satellite distance d and the signal propagation speed v, that is,

[0103] Calculate link bandwidth: The calculation of link bandwidth B depends on signal bandwidth W and modulation order M. Its mathematical expression is: B = W·log2(M);

[0104] Calculate the bit error rate: The bit error rate BER is calculated based on the energy per bit E b , unilateral noise power spectrum density N0 and Gaussian error function Q(x), whose mathematical expressions are: in,

[0105] Link simulation visualization: The calculated key parameters of the intersatellite link and the communication quality assessment results are displayed through the 3D visualization tool Unreal Engine, including link establishment, signal propagation path, loss and communication status.

[0106] Furthermore, the visualization and interaction technology module provides intuitive 3D visualization of satellite constellation dynamic behavior and communication status, and allows users to easily monitor and control the simulation process through an interactive interface. The following are the specific steps:

[0107] Visualization design and implementation: Unreal Engine UE is selected as the 3D visualization platform, and the blueprint system is used to closely integrate with C++ backend services to achieve a highly realistic 3D visualization environment;

[0108] Dynamic visualization: Through UE's real-time rendering technology, the satellite orbit, attitude and real-time status of the intersatellite link are dynamically displayed. The UE's physical engine is used to simulate various mechanical phenomena of the satellite in the space environment, making the visualization effect closer to reality.

[0109] Data synchronization: Update satellite orbit, attitude and communication data in real time through the interaction between the C++ backend and the UE frontend;

[0110] Interaction design and implementation: Design intuitive user interfaces, including dialogue sequences, form layouts, and control panels, to ensure that users can easily monitor and control the simulation process; use UE's UMG system to create user interface elements to support data presentation in the form of charts and dashboards;

[0111] Interaction logic development: Utilize the UE's blueprint system to encapsulate complex logic and interactions into visual nodes, call backend data and functions through the blueprint language, and realize dynamic update of satellite trajectory attitude visualization and intersatellite communication link visualization.

[0112] Furthermore, the specific steps of the data interaction and system testing module are:

[0113] Data interface and interaction implementation: Develop data interface to realize data exchange between visualization module and satellite orbit simulation module, satellite attitude simulation module, and intersatellite communication link simulation module, and support dynamic update of visualization content during simulation;

[0114] Performance testing and optimization: Perform performance testing on visualization and interactive technology modules, evaluate key indicators such as rendering efficiency, frame rate, and response time, and optimize based on the test results;

[0115] User training and documentation: Write detailed user manuals and operation guides to help users understand and use the simulation system, provide training services, and introduce the system's usage, precautions, and advanced functions to users;

[0116] Deployment and maintenance: Deploy the visualization and interaction technology modules to the target platform, conduct system integration testing, and provide technical support and maintenance services, including software updates, troubleshooting, and user feedback processing.

[0117] Furthermore, the process of the data interaction and system testing module in testing performance is as follows:

[0118] Test case design: Based on simulation requirements, design test cases covering the functions and performance of each module, including normal operation, abnormal conditions and boundary conditions;

[0119] Test environment construction: configure the test environment, including hardware resources, software environment and test tools, to ensure the stability and reliability of the test environment;

[0120] Automated testing: Use automated testing tools and methods to execute test cases, collect test results, and perform automatic analysis and evaluation;

[0121] White box testing: white box testing is performed on key modules of satellite orbit simulation module, satellite attitude simulation module, and intersatellite communication link simulation module to check code logic, algorithm implementation, and internal data structure;

[0122] Black box testing: Perform black box testing on the entire simulation system to verify whether the system functions and performance meet the requirements specifications;

[0123] Problem tracking and repair: Record problems found during testing, track the repair of problems, and perform regression testing to ensure that problems are completely resolved.

[0124] Figure 2 This is a flow chart of the inter-satellite link communication simulation design implementation method based on satellite constellations. Figure 2 As shown, on the other hand, a method for implementing the inter-satellite link communication simulation design based on a satellite constellation, the specific steps of the method are:

[0125] S100, satellite orbit simulation: Based on the two-body model, combined with high-precision orbit six elements, the motion trajectory of the satellite under the earth's gravitational field is calculated. During the simulation process, the irregularity of the earth's gravitational field, atmospheric resistance, and solar radiation pressure are considered to calculate and update the satellite's position and speed in real time to reflect its dynamic changes in orbit;

[0126] S200, satellite attitude simulation: Based on Euler angle and quaternion theory, it accurately simulates the attitude control and pointing of the satellite. Euler angle is used to describe the rotation angle of the satellite relative to the inertial coordinate system, while quaternion is used to avoid the "gimbal deadlock" problem. This module simulates the rotation, yaw, pitch and roll of the satellite, as well as the process of the satellite maneuvering and aligning to the target in space;

[0127] S300, intersatellite communication link simulation: responsible for calculating the key parameters of intersatellite communication, including link delay, bandwidth, signal strength and bit error rate. By monitoring the relative position and attitude between satellites in real time, the effective transmission path and loss of the link are calculated to evaluate the communication quality. In addition, this module also takes into account the particularities of electromagnetic wave propagation in the space environment, namely free space attenuation, multipath effect and atmospheric refraction;

[0128] S400, Visualization and Interaction Technology: Intuitively display the dynamic behavior and communication status of the satellite constellation. Unreal Engine UE is used in combination with C++ and Blueprint language for 3D 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.

[0129] S500, data interaction and system testing: The design of front-end and back-end interaction enables smooth data exchange, and the API interface interaction design provides seamless connection with external systems. The white box testing method is adopted in the testing phase. Through carefully designed test cases, the correctness and performance of the satellite orbit, attitude and communication functions are fully verified.

[0130] Furthermore, the S500 further includes:

[0131] Load testing: simulate high load conditions to test the performance and stability of the system under large amounts of data processing;

[0132] Stress testing: Testing the system's performance under extreme conditions to prevent system crashes and data loss;

[0133] Boundary condition testing: Testing the system's performance under boundary conditions, i.e., extremely low and high orbits, and satellite-dense areas;

[0134] Exception handling testing: Verify the system's ability to handle errors and abnormal data, and help the system respond and recover correctly;

[0135] User interface testing: Testing the usability and functionality of the user interface to ensure that users can intuitively understand and operate the system;

[0136] Real-time data testing: testing the system in a real environment to ensure the accuracy and timeliness of real-time data;

[0137] User Acceptance Testing: Conduct user acceptance testing to let end users test the simulation system, collect user feedback, and adjust and optimize the system based on user feedback.

[0138] Example 2

[0139] This embodiment implements an inter-satellite link communication simulation system based on a satellite constellation.

[0140] like Figure 1 As shown, this embodiment calculates key indicators and parameters of real-time intersatellite links based on simulated constellations to realize simulation of multiple satellite orbits around the earth, attitude simulation and communication link visualization simulation; the intersatellite communication link simulation system based on satellite constellations implemented based on Unreal Engine UE (Unreal Engine) combined with C++ and blueprint technology has stable performance, can reliably realize three-dimensional visualization and digital simulation of constellations and celestial bodies, and provide an accurate research platform for the rapid development of satellites today.

[0141] In the specific implementation, the motion trajectory of the satellite under the earth's gravitational field is calculated based on the two-body model and the six orbital elements. Specifically, the mathematical expression is defined, that is, the satellite acceleration The orbit state is described using six orbital numbers, including eccentricity, inclination, and ascending node longitude. The true anomaly angle is calculated using Kepler equations and conversion formulas. Then use the elliptical orbit equation to calculate the satellite position The J2 and J4 perturbation models are introduced to consider the impact of the non-spherical shape of the Earth on the orbit and provide more accurate orbit predictions.

[0142] Then, the satellite attitude simulation module is based on Euler angle and quaternion theory, namely 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 consider the impact of external disturbances on the satellite's attitude, such as the earth's gravitational gradient, solar radiation pressure and atmospheric drag, and calculate the changes in the satellite's attitude through numerical integration.

[0143] 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 Calculate the received power P through link budget 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 unilateral 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.

[0144] Next, the visualization and interaction technology module used Unreal Engine UE combined with C++ and Blueprint language to carry out 3D visualization development, realizing the real-time status display of satellite orbit, attitude and intersatellite link. UE was selected as the 3D visualization platform, and the blueprint system was closely integrated with the C++ back-end service to realize 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 orbit, attitude and communication data. An intuitive user interface was designed, including dialogue sequences, form layouts and control panels, to facilitate users to monitor and control the simulation process.

[0145] Finally, the data interaction and system testing module designed a data interface, 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 performed accordingly. In addition, detailed user manuals and operating guides were written, system integration testing was performed, and technical support and maintenance services were provided. During the testing phase, white-box and black-box testing methods were adopted. Through carefully designed test cases, the correctness and performance of the satellite orbit, attitude, and communication functions were comprehensively tested to ensure the stability and reliability of the system.

[0146] 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, which aims to comprehensively simulate the behavior and performance of the satellite constellation.

[0147] Example 3

[0148] This embodiment implements an inter-satellite link communication simulation method based on a satellite constellation.

[0149] like Figure 2 As shown, this embodiment aims to elaborate on the specific application and implementation process of the inter-satellite link communication simulation design and implementation method based on satellite constellation. The method of this embodiment 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 orbit six numbers and considering the irregularity of the earth's gravity field, atmospheric resistance, solar radiation pressure and other influencing factors, the method can calculate and update the position and speed of the satellite in real time, thereby realizing high-precision prediction of the satellite orbit and attitude.

[0150] First, enter the satellite orbit simulation stage (S100), select the two-body model as the satellite orbit model, consider the irregularity of the earth's gravity field, atmospheric drag, solar radiation pressure and other factors, calculate the motion trajectory of the satellite under the earth's gravity field according to the six orbital elements (semi-major axis, eccentricity, inclination, ascending node longitude, anomaly angle, true anomaly angle), 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 position and velocity of the satellite in real time to reflect its dynamic changes in orbit.

[0151] Then, the satellite attitude simulation stage (S200) is entered, and the satellite attitude is represented by Euler angles and quaternions, and the satellite's rotation, yaw, pitch and roll are simulated. Satellite attitude dynamics are applied to describe the change of satellite attitude over time, and external disturbances such as the earth's gravity gradient, solar radiation pressure, and atmospheric resistance are considered. The satellite's attitude change is calculated through numerical integration, and the satellite's attitude is updated in real time.

[0152] Secondly, enter the inter-satellite communication link simulation stage (S300), calculate the distance and relative position between satellites according to the satellite orbit and attitude information, use the free space propagation loss formula to calculate the signal loss during the propagation process, calculate the link budget, including parameters such as transmit power, receive power, and noise, evaluate the communication quality of the link, consider the particularities of electromagnetic wave propagation in space environments such as free space attenuation, multipath effect, and atmospheric refraction, and calculate key parameters such as link delay, bandwidth, signal strength, and bit error rate.

[0153] Next, we enter the visualization and interaction technology stage (S400), using Unreal Engine UE and C++ and Blueprint language for 3D visualization development, displaying the real-time status of satellite orbit, attitude and intersatellite link, designing the user interface, including dialogue sequence, form layout and control panel, to facilitate users to monitor and control the simulation process, and provide real-time data display, including satellite orbit parameters, attitude parameters and key indicators of intersatellite links, to realize interactive functions, and allow users to control the simulation process through the UI, such as starting, pausing and resetting the simulation.

[0154] Finally, enter the data interaction and system testing phase (S500), design the front-end and back-end interaction mechanisms to ensure that data can be smoothly exchanged between the client and the server, develop API interfaces to allow external systems to access and control the system, implement data input and output and automated testing, and conduct system testing, including white-box testing and black-box testing, to comprehensively verify the correctness and performance of the satellite orbit, attitude, and communication functions, conduct performance testing, and evaluate the response time and resource consumption of the simulation system under different load conditions.

[0155] A person of ordinary skill in the art can understand that all or part of the steps to implement the above embodiments can be completed by hardware, or can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium, wherein the storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0156] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the principle of the present invention. These improvements and supplements should also be regarded as the scope of protection of the present invention.

Claims

1. An inter-satellite link communication simulation system based on a satellite constellation, characterized in that: It includes satellite orbit simulation module, satellite attitude simulation module, intersatellite communication link simulation module, visualization and interaction technology module, data interaction and system testing module; The satellite orbit simulation module is used to calculate the motion trajectory of the satellite under the earth's gravitational field; The satellite attitude simulation module is used to accurately simulate the satellite's rotation, yaw, pitch and roll attitude, as well as the satellite's maneuvering and aiming process in space; The intersatellite communication link simulation module is used to calculate the effective transmission path and loss of the intersatellite communication link, and then evaluate the intersatellite communication quality; The visualization and interaction technology module is used to intuitively display the dynamic behavior and communication status of the satellite constellation, and efficiently present the real-time status of the satellite orbit, attitude and inter-satellite link; The data interaction and system testing module is used for smooth data exchange and comprehensive testing and verification of the correctness and performance of satellite orbit, attitude and communication functions.

2. A satellite constellation-based inter-satellite link communication simulation method, characterized in that The satellite constellation-based inter-satellite link communication simulation system according to claim 1 comprises the following steps: S100, satellite orbit simulation: The satellite orbit simulation module uses a two-body model as a basis, combined with high-precision orbit six elements, to calculate the motion trajectory of the satellite under the earth's gravitational field. During the simulation process, the influence factors of the irregularity of the earth's gravitational field, atmospheric resistance, and solar radiation pressure are considered, and the position and speed of the satellite are calculated and updated in real time to reflect the dynamic changes of the satellite in orbit; S200, satellite attitude simulation: The satellite attitude simulation module is based on Euler angle and quaternion theory to accurately simulate the attitude control and pointing of the satellite. Euler angle is used to describe the rotation angle of the satellite relative to the inertial coordinate system, while quaternion is used to avoid the "universal joint deadlock" problem, simulating the rotation, yaw, pitch and roll of the satellite, as well as the process of the satellite maneuvering and aligning to the target in space; S300, intersatellite communication link simulation: the intersatellite communication link simulation module calculates key parameters of intersatellite communication, including link delay, bandwidth, signal strength and bit error rate, calculates the effective transmission path and loss of the link by real-time monitoring the relative position and attitude between satellites, and then evaluates the communication quality. In addition, the intersatellite communication link simulation module also considers the particularity of electromagnetic wave propagation in the space environment, namely free space attenuation, multipath effect and atmospheric refraction; S400, visualization and interaction technology: The visualization and interaction technology module intuitively displays the dynamic behavior and communication status of the satellite constellation. It uses Unreal Engine UE combined with C++ and Blueprint language for three-dimensional visualization development, and can efficiently present the real-time status of satellite orbits, attitudes and intersatellite links. In addition, the visualization and interaction technology module also designs the user interface, including dialogue sequences and form layouts, to help users easily monitor and control the simulation process; S500, data interaction and system testing: The design of the front-end and back-end interaction of the data interaction and system testing module enables smooth data exchange, and the API interface interaction design provides seamless connection with external systems. The data interaction and system testing module adopts white box testing method in the testing phase, and comprehensively verifies the correctness and performance of satellite orbit, attitude and communication functions through carefully designed test cases.

3. The method for simulating inter-satellite link communication based on a satellite constellation according to claim 2, characterized in that Step S100 specifically includes the following sub-steps: S110. Definition of six orbital elements: six orbital elements are six basic parameters describing the state of satellite orbits, including the size of the semi-major axis a of the elliptical orbit, the eccentricity e of the orbital shape, the inclination angle i between the orbital plane and the reference plane, the longitude of the ascending node Ω where the orbital plane intersects the reference plane, the anomaly ω from the ascending node to the perigee, the true anomaly v and the mean anomaly M describing the position of the satellite on the orbit; S120. Conversion between mean anomaly and true anomaly: The mean anomaly M and true anomaly v reflect the average position and true position of the satellite in orbit. The conversion relationship between them is given by the Kepler equation: M = E-esin(E), where E is the eccentric anomaly. S130. Introduction of perturbation model: For higher-precision orbit prediction, the J2 perturbation model is introduced to consider the impact of the non-spherical shape of the earth on the orbit. For long-term orbital evolution and orbit prediction of high-orbit satellites, the J4 perturbation model is introduced to further consider higher-order terms of the earth's shape and provide more accurate orbit predictions.

4. The method for simulating inter-satellite link communication based on a satellite constellation according to claim 3, characterized in that Step S100 specifically includes the following sub-steps: S101, calculation of satellite position and velocity, i.e. determination of six orbital elements and true anomaly, calculation of satellite position and velocity using Kepler equations and Newton's laws of motion; Calculate the true anomaly: Given the eccentric anomaly E, use the conversion formula, i.e. Calculate the satellite position: Use the elliptical orbit equation to calculate the satellite's position in the orbital plane, that is, r is the distance from the satellite to the central body; Calculate satellite velocity: Use Kepler's second law and Newton's laws of motion to calculate the velocity, i.e.

5. The method for simulating inter-satellite link communication based on a satellite constellation according to claim 4, characterized in that Step S200 specifically includes the following sub-steps: S210, Satellite attitude representation: Satellite attitude is represented by Euler angles and quaternions. Euler angles describe the position of the satellite relative to a fixed reference coordinate system through three consecutive rotation angles, while quaternions provide a representation method to avoid gimbal deadlock. S220, Applied Satellite Attitude Dynamics: Describes the change of satellite attitude over time. In the absence of external torque, the satellite attitude will remain unchanged. Due to external disturbances, i.e., the Earth's gravitational gradient, solar radiation pressure, and atmospheric drag, the satellite attitude will change; S230, Dynamic equation of Euler angle: For Euler angle, the posture dynamics is expressed as: φ, θ, ψ are Euler angles, I x ,I y ,I z is the moment of inertia of the satellite's main axis, M x 、M y 、M z is the external torque exerted on the satellite; S40, Quaternion dynamics equation: For quaternion, the rotation representing the attitude change, the attitude dynamics is expressed as: Ω(q) is a matrix associated with the quaternion q, M is the external moment vector; S250, attitude simulation calculation: Based on the Euler angle, quaternion attitude representation method and dynamic equations, numerical integration is performed to calculate the satellite's attitude changes.

6. The method for simulating inter-satellite link communication based on a satellite constellation according to claim 5, characterized in that Step S300 specifically includes the following sub-steps: S310, calculate the distance between satellites: calculate the distance between any two satellites according to the satellite position information provided by the satellite orbit simulation module (x1, y1, z1) and (x2, y2, z2) are the position coordinates of the two satellites respectively; S320, Calculate free space propagation loss: Use the free space propagation loss formula to calculate the signal loss L during propagation. f ,Right now d is the distance between satellites, λ is the wavelength of the signal; S330, calculate link budget: The link budget includes parameters of transmit power, receive power, and noise. Calculate receive power P r , that is, P r =P t +G t +G r -LL f , P t is the transmit power, G t is the transmit antenna gain, G r is the receiving antenna gain, L is the system loss, and L f is the free space loss; S340, calculate the signal transmission delay: the signal transmission delay is determined by the inter-satellite distance d and the signal propagation speed v, that is, S350, calculating the link bandwidth: 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); S360, calculate the bit error rate: the bit error rate BER is calculated based on the energy per bit E b , unilateral noise power spectrum density N0 and Gaussian error function Q(x), whose mathematical expressions are: in, 7. The method for simulating inter-satellite link communication based on a satellite constellation according to claim 6, characterized in that Step S400 specifically includes the following sub-steps: S410, Visualization Design and Implementation: Unreal Engine UE is selected as the 3D visualization platform, and the blueprint system is used to closely integrate with C++ backend services to achieve a highly realistic 3D visualization environment; S420, Dynamic Visualization: Through the real-time rendering technology of UE, the real-time status of satellite orbit, attitude and intersatellite link is dynamically displayed. The physics engine of UE is used to simulate various mechanical phenomena of satellite in space environment, making the visualization effect closer to reality. S430, data synchronization: through the interaction between the C++ backend and the UE front end, the satellite orbit, attitude and communication data are updated in real time; S440, Interaction Design and Implementation: Design intuitive user interfaces, including dialogue sequences, form layouts, and control panels, to ensure that users can easily monitor and control the simulation process; use UE's UMG system to create user interface elements to support data presentation in the form of charts and dashboards; S450, interactive logic development: Utilize the UE's blueprint system to encapsulate complex logic and interactions into visual nodes, call backend data and functions through the blueprint language, and realize dynamic update of satellite trajectory attitude visualization and intersatellite communication link visualization.

8. The method for simulating inter-satellite link communication based on a satellite constellation according to claim 7, characterized in that Step S500 specifically includes the following sub-steps: S510, data interface and interaction implementation: Develop data interface to realize data exchange between visualization module and satellite orbit simulation module, satellite attitude simulation module and intersatellite communication link simulation module, and support dynamic update of visualization content during simulation; S520, Deployment and Maintenance: Deploy the visualization and interaction technology modules to the target platform, conduct system integration testing, and provide technical support and maintenance services, including software updates, troubleshooting, and user feedback processing.

9. The method for simulating inter-satellite link communication based on a satellite constellation according to claim 1, characterized in that The data interaction and system testing module tests the performance including the following steps: Test case design: Based on simulation requirements, design test cases covering the functions and performance of each module, including normal operation, abnormal conditions and boundary conditions; Test environment construction: configure the test environment, including hardware resources, software environment and test tools, to ensure the stability and reliability of the test environment; Automated testing: Use automated testing tools and methods to execute test cases, collect test results, and perform automatic analysis and evaluation; White box testing: white box testing is performed on key modules of satellite orbit simulation module, satellite attitude simulation module, and intersatellite communication link simulation module to check code logic, algorithm implementation, and internal data structure; Black box testing: Perform black box testing on the entire simulation system to verify whether the system functions and performance meet the requirements specifications; Problem tracking and repair: Record problems found during testing, track the repair of problems, and perform regression testing to ensure that problems are completely resolved.

10. The method for implementing the satellite constellation-based inter-satellite link communication simulation design according to claim 9, characterized in that The data interaction and system testing module further includes the following steps to test the performance: Load testing: simulate high load conditions to test the performance and stability of the system under large amounts of data processing; Stress testing: Testing the system's performance under extreme conditions to prevent system crashes and data loss; Boundary condition testing: Testing the system's performance under boundary conditions, i.e., extremely low and high orbits, and satellite-dense areas; Exception handling testing: Verify the system's ability to handle errors and abnormal data, and help the system respond and recover correctly; User interface testing: Testing the usability and functionality of the user interface to ensure that users can intuitively understand and operate the system; Real-time data testing: testing the system in a real environment to ensure the accuracy and timeliness of real-time data; User Acceptance Testing: Conduct user acceptance testing to let end users test the simulation system, collect user feedback, and adjust and optimize the system based on user feedback.

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