A method for ocean data communication based on non-geostationary low-orbit small satellites

Abstract

The present invention provides a method for offshore data communication based on a non-geostationary low-orbit small satellite, comprising: when a satellite network automation management system receives a signaling command from a maritime satellite relay communication terminal within a target sea area to transmit uplink data, the signaling is analyzed to determine the privacy requirements, timeliness requirements, and recipient information of the information; when the privacy requirements and timeliness requirements meet preset conditions, the target low-orbit satellite is determined based on the location of the maritime satellite relay communication terminal and the recipient information; the target low-orbit satellite receives the uplink data transmitted by the maritime satellite relay communication terminal and caches it; when the target low-orbit satellite moves to a position covering the recipient, the downlink data is transmitted to the recipient. By implementing the present invention, data with high privacy requirements and low timeliness requirements is transmitted via a low-orbit satellite with a delayed transmission until it reaches the recipient's location, and the data is transmitted to the recipient, which can reduce the frequency of intermediate transmissions and reduce the risk of data leakage.

Description

Technical Field

[0001] The present invention belongs to the technical field of information transmission, and in particular relates to a method for communicating data over the open sea based on a small non-geostationary low-orbit satellite. Background Art

[0002] Low-orbit satellites have the characteristics of small size, low launch cost, rapid technological updates, and global coverage. They can improve the ability to communicate directly with ground terminals and have broad development prospects in the era of rapid development of satellite communication networks.

[0003] Traditional low-orbit satellite data transmission methods typically require satellites to transmit data via intersatellite links after receiving it until it reaches the target user. This method is suitable for data with high timeliness requirements and low privacy requirements. Due to the high-speed movement of low-orbit satellites and the complexity of satellite networks, data may pass through multiple relay satellites during transmission, increasing the risk of data leakage. Therefore, it is no longer suitable for data with low timeliness requirements and high privacy requirements. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a method and device for ocean data communication based on a non-geostationary low-orbit small satellite to meet the demand for improving the privacy of data transmission.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] According to a first aspect, the present invention provides a method for far sea data communication based on a non-geostationary low-orbit small satellite, comprising: when a satellite network automation management system receives a signaling from a maritime satellite relay communication terminal within a target sea area to send uplink data, the signaling is analyzed to determine the privacy requirements, timeliness requirements and recipient information of the information; when the privacy requirements and timeliness requirements meet preset conditions, the target low-orbit satellite is determined based on the position of the maritime satellite relay communication terminal and the recipient information; the target low-orbit satellite receives the uplink data sent by the maritime satellite relay communication terminal and caches the uplink data; when the target low-orbit satellite moves to a position covering the recipient, the downlink data is sent to the recipient.

[0007] Optionally, the target low-orbit satellite is determined based on the position of the maritime satellite relay communication terminal and the receiver information, including: determining a first low-orbit satellite set based on the signal coverage of all low-orbit satellites and the position of the maritime satellite relay communication terminal; judging whether there is a low-orbit satellite whose signal coverage covers the receiver in the first low-orbit satellite set, and if so, using the low-orbit satellite as the target low-orbit satellite; if not, selecting a low-orbit satellite in the first low-orbit satellite set whose minimum distance between the signal coverage and the receiver position is less than a preset threshold to obtain a second low-orbit satellite set; determining the minimum orbit change cost of a low-orbit satellite in the second low-orbit satellite set to change orbit to a target position during operation, wherein the target position is a position where the signal coverage covers the receiver; and determining the target low-orbit satellite based on the minimum orbit change cost of the low-orbit satellite in the second low-orbit satellite set.

[0008] Optionally, determining the minimum orbit change cost of a low-orbit satellite in the second low-orbit satellite set when changing its orbit to a target position during operation includes: determining the optimal trajectory of each low-orbit satellite when changing its orbit to the target position under energy consumption constraints and time constraints based on the fixed operating orbits and target positions of all low-orbit satellites in the second low-orbit satellite set; determining the collision probability of each low-orbit satellite based on the optimal trajectory of each low-orbit satellite when changing its orbit to the target position, and taking multiple low-orbit satellites with a collision probability lower than a preset probability as the third low-orbit satellite set; and determining the comprehensive energy consumption and time cost of each low-orbit satellite in the third low-orbit satellite set based on the optimal trajectory of each low-orbit satellite in the third low-orbit satellite set.

[0009] Optionally, based on the fixed operating orbits and target positions of all low-orbit satellites in the second low-orbit satellite set, the optimal trajectory of each low-orbit satellite when changing orbit to the target position is determined under energy consumption constraints and time constraints, including: obtaining current state parameters; inputting the current state parameters into the current policy network in the reinforcement learning model, determining the next state parameter set, and using the reward function and the next state parameter set to determine the rewards corresponding to multiple next states, wherein the reward function is determined comprehensively based on energy consumption and time costs; inputting the rewards corresponding to multiple next states into the value function to obtain multiple values, and selecting the next state corresponding to the highest value function as the target state; based on the current state and the target state, determining the optimal trajectory of the low-orbit satellite when changing orbit to the target position.

[0010] Optionally, the reward function is:

[0011]

[0012] Among them, R(s,ac) represents the reward function, s represents the current state, ac represents the action taken in the state, α, β, and γ are weight coefficients respectively, and F thIndicates the thrust, v t represents the speed from the current state to the next state, S represents the straight-line distance from the current state to the target position, and ΔS represents the difference between the straight-line distance from the current state to the target position and the straight-line distance from the target state to the target position.

[0013] Optionally, based on the fixed operating orbits and target positions of all low-orbit satellites in the second low-orbit satellite set, the optimal trajectory of each low-orbit satellite when changing its orbit to the target position is determined under energy consumption constraints and time constraints, including: establishing an optimal trajectory control model based on energy consumption constraints and time constraints based on the orbit differential equation of the low-orbit satellite based on the Gaussian perturbation equation and the continuous directional thrust direction angle function based on Fourier series fitting; solving the optimal solution of the optimal trajectory control model according to the particle swarm optimization algorithm to obtain the optimal trajectory.

[0014] Optionally, the collision probability of each low-orbit satellite is determined based on the optimal trajectory of each low-orbit satellite when it changes orbit to the target position, including: obtaining the operating position and operating speed of all other low-orbit satellites; determining the spatial positions of multiple target time points during the operation process based on the operating position and operating speed, wherein the target time point is an arbitrarily selected time point in the time period when the low-orbit satellite changes orbit to the target position; connecting the spatial positions of multiple time points to obtain the rough orbits of the multiple low-orbit satellites; judging whether there is an intersection between the rough orbits of the multiple low-orbit satellites and the optimal trajectory when the low-orbit satellite changes orbit to the target position, and if so, marking the collision probability as the first collision probability; if not, marking the collision probability as the second collision probability.

[0015] Optionally, when the privacy requirements and timeliness requirements do not meet the preset conditions, the target low-orbit satellite is determined based on the position of the maritime satellite relay communication terminal; the target low-orbit satellite receives the uplink data sent by the maritime satellite relay communication terminal, and sends the data to the recipient based on the inter-satellite link.

[0016] According to the second aspect, an embodiment of the present invention provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the steps of the method for far-sea data communication based on a non-geostationary low-orbit small satellite as described in the first aspect or any embodiment of the first aspect.

[0017] According to the third aspect, an embodiment of the present invention provides a computer storage medium having computer instructions stored thereon, which, when executed by a processor, implement the steps of the method for far-sea data communication based on a non-geostationary low-orbit small satellite as described in the first aspect or any embodiment of the first aspect.

[0018] An embodiment of the present invention provides a method for communicating data over the open sea based on a non-geostationary low-orbit small satellite. By determining the privacy and timeliness requirements of the information, data with high privacy requirements and low timeliness requirements are sent in a delayed manner via a low-orbit satellite until it reaches the receiver's location. The data is then transmitted to the receiver, which can effectively reduce the frequency of intermediate transmissions and lower the risk of data leakage.

[0019] Other advantages, objectives and features of the present invention will be described in the following description and will be apparent to those skilled in the art to some extent, or those skilled in the art can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to make the purpose, technical solutions and beneficial effects of the present invention more clear, the present invention provides the following drawings for illustration:

[0021] Figure 1 This is a specific example flow chart of a method for ocean data communication based on a non-geostationary low-orbit small satellite in the present invention;

[0022] Figure 2 This is a schematic diagram of a specific example module of a high-sea data communication device based on a non-geostationary low-orbit small satellite in the present invention;

[0023] Figure 3 This is a principle block diagram of a specific example of an electronic device in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0025] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components; wireless connections or wired connections. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0026] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0027] The embodiment of the present invention provides a method for ocean data communication based on a non-geostationary low-orbit small satellite, such as Figure 1 As shown, including:

[0028] S101, when the satellite network automation management system receives a signaling message from a maritime satellite relay communication terminal within the target sea area to transmit uplink data, the system analyzes the signaling message to determine privacy requirements, timeliness requirements, and recipient information of the information;

[0029] S102, when the privacy requirement and timeliness requirement meet the preset conditions, determining the target low-orbit satellite based on the location of the maritime satellite relay communication terminal and the receiver information;

[0030] S103, the target low-orbit satellite receives the uplink data sent by the maritime satellite relay communication terminal and buffers the uplink data;

[0031] S104: When the target low-orbit satellite moves to a position covering the receiver, downlink data is sent to the receiver.

[0032] For example, an automated satellite network management system refers to a system for managing and controlling a low-orbit satellite constellation, enabling automated satellite operation and management. Within the automated satellite network management system, areas requiring key information protection can be pre-demarcated. In this embodiment, to achieve private communication of data in the target offshore waters, the target offshore waters can be pre-demarcated as areas requiring key information protection.

[0033] A maritime satellite relay communication terminal is a device used to transmit data via satellite in a maritime environment. It is typically installed on ships, buoys, or other offshore platforms, and can transmit acquired data via satellite relay to a shore-based base station or other receiving terminal. When the satellite network automation management system receives signaling from a maritime satellite relay communication terminal within the target sea area to send uplink data, it parses the signaling to determine the privacy and timeliness requirements of the information. Since signaling generally does not directly carry privacy and timeliness requirements, but can carry encryption keys or encryption algorithm identifiers and priority information, the parsing method can be to determine whether the signaling carries the above information. If it carries the encryption key or encryption algorithm identifier but not priority information, it is considered that the information has a high privacy requirement and a low timeliness requirement, meeting the preset conditions.

[0034] For information with high privacy requirements and low timeliness requirements, if it is forwarded using an intersatellite link, its security is low. Therefore, for this type of information, the method proposed in this embodiment first determines a target low-orbit satellite. When the information covers the maritime satellite relay communication terminal, the target low-orbit satellite receives the uplink data of the maritime satellite relay communication terminal and stores the uplink data. When the information reaches the receiver, it sends the downlink data to the receiver, thereby improving the privacy of information transmission.

[0035] The receiver information may include the receiver's identification information, location information, device type and function, and communication parameters. First, the receiver's location is determined by parsing the receiver information carried in the signaling. Then, based on the location of the maritime satellite relay communication terminal and the receiver's location, a determination is made as to whether a low-orbit satellite exists that covers both. If so, the information transmission task is assigned to that low-orbit satellite. A ground control center typically maintains a user location database that records the location information of user terminal devices. When the receiver needs to receive information, the ground control center can direct a satellite to transmit the information to the receiver's location based on the information in the database, completing the information transmission. If no such satellite exists, the ground control center randomly selects a low-orbit satellite from among those covering the maritime satellite relay communication terminal's location and assigns the information transmission task to that satellite. To ensure data transmission, the low-orbit satellite must maneuver according to the receiver's location, including adjusting its orbital parameters, such as its inclination and altitude. Therefore, a low-orbit satellite with the lowest orbital maneuvering cost can be selected as the satellite for information transmission. This embodiment does not limit the method for selecting the target low-orbit satellite, and those skilled in the art can determine this as needed.

[0036] An embodiment of the present invention provides a method for communicating data over the open sea based on a non-geostationary low-orbit small satellite. By determining the privacy and timeliness requirements of the information, data with high privacy requirements and low timeliness requirements are sent in a delayed manner via a low-orbit satellite until it reaches the receiver's location. The data is then transmitted to the receiver, which can effectively reduce the frequency of intermediate transmissions and lower the risk of data leakage.

[0037] As an optional implementation, the target low-orbit satellite is determined according to the position of the maritime satellite relay communication terminal and the position of the receiver, including: determining a first low-orbit satellite set according to the signal coverage of all low-orbit satellites and the position of the maritime satellite relay communication terminal; judging whether there is a low-orbit satellite whose signal coverage covers the receiver in the first low-orbit satellite set, and if so, using the low-orbit satellite as the target low-orbit satellite; if not, selecting a low-orbit satellite in the first low-orbit satellite set whose minimum distance between the signal coverage and the receiver position is less than a preset threshold to obtain a second low-orbit satellite set; determining the minimum orbit change cost of a low-orbit satellite in the second low-orbit satellite set to change orbit to a target position during operation, wherein the target position is a position where the signal coverage covers the receiver; and determining the target low-orbit satellite according to the minimum orbit change cost of the low-orbit satellite in the second low-orbit satellite set.

[0038] For example, low-orbit satellites generally operate in fixed orbits, and the signal coverage range is calculated based on the fixed orbit path, orbital altitude, and satellite-to-ground distance. Determine whether the signal coverage range of each low-orbit satellite orbiting the earth includes the receiver's location, and use all low-orbit satellites whose signal coverage range includes the receiver's location as the first low-orbit satellite set. Determine whether there is a satellite in the first low-orbit satellite set whose coverage range includes the receiver's location. If so, use the low-orbit satellite as the target low-orbit satellite for information transmission. If not, select a low-orbit satellite in the first low-orbit satellite set whose minimum distance between the signal coverage range and the receiver's location is less than a preset threshold to obtain a second low-orbit satellite set. Based on the distance between the signal coverage range and the receiver's location, some low-orbit satellites with a closer distance are screened to reduce the computational complexity of the subsequent orbit change cost.

[0039] The distance can be calculated using the Euclidean distance formula applied to three-dimensional space. The minimum distance can be determined by treating each low-orbit satellite coverage trajectory as a spatial curve and the receiver position as a spatial point. Calculus is used to find the minimum value from the spatial curve to the spatial point. Specifically, the shortest distance can be solved by taking a derivative. The following is a specific implementation method:

[0040] Assume that the trajectory curve of the low-orbit satellite coverage range is: r(t) = (x(t), y(t), z(t)), and the receiver position is: P(x0, y0, z0); in order to find the shortest distance, it is necessary to construct a minimum distance function, which can be obtained by derivation:

[0041]

[0042] By solving the above formula, we get the value of t, and then we put it into the following distance formula to get the minimum distance d:

[0043]

[0044] All low-orbit satellites with a minimum distance less than a preset threshold are taken as a second low-orbit satellite set, and the minimum orbit change cost of changing the orbit to the target position during the operation of the low-orbit satellite is determined in the second low-orbit satellite set. The low-orbit satellite corresponding to the minimum value among multiple minimum orbit change costs is selected as the target satellite.

[0045] The minimum orbit change cost is measured in terms of energy loss and time. Specifically, as an optional implementation method, the minimum orbit change cost of a low-orbit satellite in the second low-orbit satellite set changing its orbit to a target position during operation is determined, including: determining the optimal trajectory of each low-orbit satellite when changing its orbit to the target position under energy and time constraints based on the fixed operating orbits and target positions of all low-orbit satellites in the second low-orbit satellite set; determining the collision probability of each low-orbit satellite based on the optimal trajectory of each low-orbit satellite when changing its orbit to the target position, and taking multiple low-orbit satellites with a collision probability lower than a preset probability as the third low-orbit satellite set; and determining the comprehensive energy and time cost of each low-orbit satellite in the third low-orbit satellite set based on the optimal trajectory of each low-orbit satellite in the third low-orbit satellite set.

[0046] For example, the optimal trajectory for each low-orbit satellite when maneuvering to a target location under energy and time constraints can be determined using reinforcement learning. This involves optimizing the low-thrust maneuver strategy while taking into account the effects of various orbital perturbations and the Earth's shadow constraint to achieve the optimal time-based orbit transfer. The optimal trajectory is determined using reinforcement learning as follows:

[0047] Based on the fixed operating orbits and target positions of all low-orbit satellites in the second low-orbit satellite set, the optimal trajectory of each low-orbit satellite when changing orbit to the target position is determined under energy consumption constraints and time constraints, including: obtaining current state parameters; inputting the current state parameters into the current policy network in the reinforcement learning model, determining the next state parameter set, and using the reward function and the next state parameter set to determine the rewards corresponding to multiple next states, wherein the reward function is comprehensively determined based on energy consumption and time costs; inputting the rewards corresponding to the multiple next states into the value function to obtain multiple values, and selecting the next state corresponding to the highest value function as the target state; and determining the optimal trajectory of the low-orbit satellite when changing orbit to the target position based on the current state and the target state.

[0048] Specifically, before using a reinforcement learning model to find a strategy, a satellite orbital environment model is first constructed for offline learning. This process involves describing the satellite's initial position, velocity, target position, and the effects of various forces in space (such as Earth's gravity and atmospheric drag) on ​​its motion. Next, a state space is defined. The state can include information such as the satellite's position (3D coordinates), velocity (3D velocity vector), and remaining fuel. These state variables fully describe the satellite's state in orbit. The actions that the satellite can take are then determined, essentially constructing an action space. For example, turning thrusters on and off in different directions can change the magnitude and direction of the velocity. Each action results in a change in the satellite's state.

[0049] The reward function is designed by considering energy consumption constraints and time constraints. For example, to meet the energy consumption constraint, energy consumption can be penalized; to meet the time constraint, a higher reward is given when the satellite reaches the target location within the specified time, and a lower reward or penalty is given when the time limit is exceeded. The reward function provided in this embodiment is:

[0050]

[0051] Among them, R(s,ac) represents the reward function, s represents the current state, ac represents the action taken in the state, α, β, and γ are weight coefficients respectively, and F th Indicates the thrust, v t represents the speed from the current state to the next state, S represents the straight-line distance from the current state to the target position, and ΔS represents the difference between the straight-line distance from the current state to the target position and the straight-line distance from the target state to the target position.

[0052] Next, a Deep Q-Network (DQN) is selected for initial training using historical or simulated data. Based on the current state, an action is selected, which is applied to the satellite orbit model to change the satellite's state. Rewards are calculated based on the new state and a predefined reward function, and the policy network is updated. Information such as state, action, and reward is stored in an experience replay buffer. Data is periodically sampled from the experience replay buffer to update the parameters of the reinforcement learning algorithm to optimize the policy, enabling the low-orbit satellite to select better actions and obtain higher rewards.

[0053] This embodiment relies on the construction and training process of the reinforcement learning model described above. When actually using the reinforcement learning model to obtain the optimal trajectory, the current state parameters include the current position, velocity, energy consumption, and other parameters of the low-orbit satellite. The current state parameters are input into the current policy network within the reinforcement learning model to determine the next state parameter set. Using the reward function and the next state parameter set, the rewards corresponding to multiple next states are determined. These rewards are then input into the value function to obtain multiple values. The next state corresponding to the highest value function is selected as the target state. Based on the current state and the target state, the optimal trajectory for the low-orbit satellite to change orbit to the target position is determined. The value function is used to evaluate the expected long-term reward of a state or state-action pair.

[0054] In addition to determining the optimal trajectory of each low-orbit satellite when changing orbit to the target position under energy consumption constraints and time constraints through reinforcement learning as mentioned above, the optimal trajectory can also be determined in the following way: according to the orbit differential equation of the low-orbit satellite based on the Gaussian perturbation equation and the continuous directional thrust direction angle function based on Fourier series fitting, an optimal trajectory control model based on energy consumption constraints and time constraints is established; the optimal solution of the optimal trajectory control model is solved using the particle swarm optimization algorithm to obtain the optimal trajectory.

[0055] For example, during the orbit change process, the satellite's orbital elements will change due to the applied thrust, and the perturbation caused by the thrust can be reflected by modifying the perturbation force term in the Gaussian perturbation equation. By incorporating the orbit change thrust into the Gaussian perturbation equation, the dynamic change process of the satellite orbit under the action of thrust can be accurately simulated. The orbit differential equation of the Gaussian perturbation equation of the satellite orbit under the action of thrust for a low-orbit satellite is given below:

[0056]

[0057] Where a is the semi-major axis, e is the eccentricity, i is the orbital inclination, γ is the right ascension of the ascending node, ω is the argument of perigee, z is the true anomaly, n is the mean motion, r is the distance from the center of the satellite, E is the eccentric anomaly, p is the semi-diameter, and F is the orbital inclination. r_all It represents the radial component of the resultant force of thrust and perturbation in the orbital coordinate system, F t_all It represents the lateral component of the resultant force of thrust and perturbation in the orbital coordinate system, F n_all It represents the normal component of the resultant force of thrust and perturbation in the orbital coordinate system.

[0058] The continuous directional thrust direction angle function based on Fourier series fitting is:

[0059]

[0060] Among them, M is the Fourier series, a0,am ,b m is the Fourier coefficient, and T represents the period. The above function shows the direction change of thrust of low-orbit satellite at different times.

[0061] According to the orbit differential equation of the low-orbit satellite based on the Gaussian perturbation equation and the continuous directional thrust direction angle function based on Fourier series fitting, the optimal trajectory control model based on energy consumption constraints and time constraints is established as follows:

[0062]

[0063] stE≤E max ;

[0064] T target -T ini ≤T max ;

[0065] P i 、P target_i Satisfy formulas (1)-(6);

[0066] Among them, λ i Represents the weight coefficient, P i Indicates the final actual satellite orbit parameters, P target_i represents the orbital parameters of the target position, that is, the orbital parameters that can cover the signal range of the receiver, E represents the actual energy consumption, E max is the maximum energy consumption, T max is the maximum time difference, T target It represents the time it takes for the low-orbit satellite to reach the target location, T ini Indicates the initial time of the low-orbit satellite.

[0067] By building the optimal trajectory control model, a particle swarm is constructed, and the optimal trajectory is solved according to the particle swarm optimization algorithm. The particle swarm consists of multiple particles, each of which represents a possible trajectory solution. The position vector of each particle corresponds to the decision variable in the optimization problem (such as the Fourier coefficient), and the velocity vector represents the moving speed of the particle in the search space. During initialization, the position and velocity of the particle are randomly generated. For each particle, its position vector is substituted into the optimal trajectory control model and the optimal trajectory is calculated. The value of is used as the fitness value of the particle. The smaller the fitness value, the better the trajectory corresponding to the particle.

[0068] An embodiment of the present invention provides a method for ocean data communication based on a non-geostationary low-orbit small satellite. Through the above two methods, the optimal trajectory can be obtained, so as to facilitate subsequent evaluation of the optimal trajectory and selection of the optimal low-orbit satellite for data transmission.

[0069] As an optional implementation, the collision probability of each low-orbit satellite is determined based on the optimal trajectory of each low-orbit satellite when it changes orbit to the target position, including: obtaining the operating position and operating speed of all other low-orbit satellites; determining the spatial positions of multiple target time points during the operation process based on the operating position and operating speed, wherein the target time point is an arbitrarily selected time point in the time period when the low-orbit satellite changes orbit to the target position; connecting the spatial positions of multiple time points to obtain the rough orbits of multiple low-orbit satellites; judging whether there is an intersection between the rough orbits of multiple low-orbit satellites and the optimal trajectory when the low-orbit satellite changes orbit to the target position, and if so, marking the collision probability as the first collision probability; if not, marking the collision probability as the second collision probability.

[0070] For example, if the current position and speed of the satellite are known, the satellite's equation of motion can be established. The target time point can be arbitrarily selected during the time period from the low-orbit satellite changing orbit to the target position, can be selected at equal intervals, or can be selected based on specific needs, which is not limited in this embodiment. For each low-orbit satellite, the calculated spatial positions of different target time points are connected in chronological order to form a continuous curve, which is the rough trajectory of the satellite. For example, assuming that the position of the satellite at three time points is obtained, these points are connected in sequence with straight line segments to form a broken line. When the time interval is small and the orbit is relatively stable, this broken line can approximately represent the satellite's trajectory. For the optimal trajectory of the changing orbit satellite and the rough trajectories of other low-orbit satellites, it is necessary to check whether they intersect within the same time period.

[0071] When it is determined that there is an intersection, it is considered that the possibility of a collision is greater and is marked as the first collision probability. This first collision probability can be a relatively high value, such as 90%. The specific value needs to be set according to the risk assessment and accuracy requirements of the task. When there is no intersection, it is marked as the second collision probability. The second collision probability is usually lower, indicating that the collision risk is smaller, but it does not mean absolute safety, because the calculation of the trajectory is based on certain assumptions and approximations, and there are other factors that are not considered in practice (such as orbital perturbations, errors, etc.), so it can be set to 20%. This embodiment does not limit the method for determining the size of the first collision probability and the second collision probability.

[0072] An embodiment of the present invention provides a method for ocean data communication based on a small satellite in a non-geostationary low-orbit orbit. For multiple satellites, by comparing the trajectories of different satellites, their relative position relationship in space can be more clearly seen, thereby making a preliminary judgment on whether there may be a collision risk, providing a basis for subsequent detailed analysis. In addition, the target time point can be arbitrarily selected within the time period when the low-orbit satellite changes its orbit to the target position. Therefore, the number of time points can be flexibly adjusted according to different accuracy requirements and computing resources.

[0073] As an optional implementation method, when the privacy requirements and timeliness requirements do not meet the preset conditions, the target low-orbit satellite is determined based on the position of the maritime satellite relay communication terminal; the target low-orbit satellite receives the uplink data sent by the maritime satellite relay communication terminal and sends the data to the recipient based on the inter-satellite link.

[0074] An embodiment of the present invention provides a method for communicating data over the open sea based on a small, non-geostationary low-orbit satellite, which provides another channel for information that does not require high privacy but has low timeliness requirements, thereby ensuring the rapid transmission of data with high timeliness.

[0075] The present invention provides a remote sea data communication device based on a non-geostationary low-orbit small satellite, such as Figure 2 As shown, including:

[0076] The demand determination module 201 is configured to analyze the signaling to determine the privacy requirements, timeliness requirements, and recipient information of the information when the satellite network automation management system receives a signaling from a maritime satellite relay communication terminal within the target sea area to transmit uplink data;

[0077] The target low-orbit satellite determination module 202 is configured to determine the target low-orbit satellite based on the location of the maritime satellite relay communication terminal and the receiver information when the privacy requirement and the timeliness requirement meet the preset conditions;

[0078] The buffer module 203 is used for the target low-orbit satellite to receive the uplink data sent by the maritime satellite relay communication terminal and buffer the uplink data;

[0079] The data sending module 204 is configured to send downlink data to the receiver when the target low-orbit satellite moves to a position covering the receiver.

[0080] The present application also provides an electronic device, such as Figure 3 As shown, a processor 501 and a memory 502 , wherein the processor 501 and the memory 502 may be connected via a bus or other means.

[0081] The processor 501 may be a central processing unit (CPU). The processor 501 may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or a combination of the above chips.

[0082] Memory 502, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, and modules, such as the program instructions / modules corresponding to the method for ocean data communication based on non-geostationary low-orbit small satellites in embodiments of the present invention. The processor executes the non-transitory software programs, instructions, and modules stored in memory to perform various processor functions and data processing.

[0083] The memory 502 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created by the processor, etc. In addition, the memory may include a high-speed random access memory, and may also include a non-transitory memory, such as at least one disk storage device, a flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory 502 may optionally include a memory remotely located relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0084] The one or more modules are stored in the memory 502 and when executed by the processor 501, perform the following steps: Figure 1 The embodiment shown is a method for communicating data over distant seas based on a small non-geostationary low-orbit satellite.

[0085] For details of the above electronic equipment, please refer to Figure 1 The corresponding descriptions and effects in the embodiments shown can be understood and will not be repeated here.

[0086] This embodiment also provides a computer storage medium storing computer-executable instructions capable of executing the method for ocean data communication based on a non-geostationary low-orbit small satellite in any of the above-mentioned method embodiments. The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), a random access memory (RAM), a flash memory, a hard disk drive (HDD), or a solid-state drive (SSD); the storage medium may also include a combination of the above-mentioned types of memory.

[0087] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A method for offshore data communication based on a non-geostationary low-orbit small satellite, characterized in that: include: When the satellite network automation management system receives a signal from a maritime satellite relay communication terminal within the target sea area to send uplink data, it analyzes the signal to determine the privacy requirements, timeliness requirements, and recipient information of the information; When the privacy and timeliness requirements meet the preset conditions, the target low-orbit satellite is determined based on the location of the maritime satellite relay communication terminal and the receiver information. The preset conditions are that the information privacy requirement is high and the timeliness requirement is low; The target low-orbit satellite receives the uplink data sent by the maritime satellite relay communication terminal and caches the uplink data; When the target low-orbit satellite moves to a position covering the receiver, it sends downlink data to the receiver.

2. The method for ocean data communication based on a non-geostationary low-orbit small satellite according to claim 1, characterized in that: Determine the target low-orbit satellite based on the location of the maritime satellite relay communication terminal and the receiver information, including: Determine a first low-orbit satellite set based on the signal coverage of all low-orbit satellites and the location of the maritime satellite relay communication terminal; Determine whether there is a low-orbit satellite in the first low-orbit satellite set whose signal coverage covers the receiver, and if so, use the low-orbit satellite as the target low-orbit satellite; If no such satellite exists, a low-orbit satellite having a minimum distance between its signal coverage and the receiver's location less than a preset threshold is selected from the first low-orbit satellite set to obtain a second low-orbit satellite set; Determine a minimum orbit change cost for a low-orbit satellite in the second low-orbit satellite set to change its orbit to a target position during operation, wherein the target position is a position where the signal coverage range includes the receiver; The target low-orbit satellite is determined according to the minimum orbit change cost of the low-orbit satellites in the second low-orbit satellite set.

3. The method for ocean data communication based on a non-geostationary low-orbit small satellite according to claim 2, characterized in that: Determine the minimum orbit change cost for a low-orbit satellite in the second low-orbit satellite set to change its orbit to a target position during operation, including: Based on the fixed orbits of all low-orbit satellites in the second low-orbit satellite set and the target position, determine the optimal trajectory of each low-orbit satellite when changing its orbit to the target position under energy consumption constraints and time constraints; Determining the collision probability of each low-orbit satellite based on the optimal trajectory of each low-orbit satellite when it changes orbit to the target position, and selecting multiple low-orbit satellites with collision probabilities lower than a preset probability as a third low-orbit satellite set; According to the optimal trajectory of each low-orbit satellite in the third low-orbit satellite set, the comprehensive cost of energy consumption and time of each low-orbit satellite in the third low-orbit satellite set is determined.

4. The method for ocean data communication based on a non-geostationary low-orbit small satellite according to claim 3, characterized in that: Based on the fixed orbits of all low-orbit satellites in the second low-orbit satellite set and the target position, the optimal trajectory of each low-orbit satellite when changing its orbit to the target position is determined under energy consumption constraints and time constraints, including: Get current status parameters; Input the current state parameters into the current policy network in the reinforcement learning model, determine the next state parameter set, and use the reward function and the next state parameter set to determine the rewards corresponding to multiple next states, where the reward function is determined based on the energy consumption and time cost. Input the rewards corresponding to multiple next states into the value function to obtain multiple values, and select the next state corresponding to the highest value function as the target state; Based on the current state and target state, the optimal trajectory of the low-orbit satellite when changing orbit to the target position is determined.

5. The method for ocean data communication based on non-geostationary low-orbit small satellite according to claim 4, characterized in that: The reward function is: ； in, represents the reward function, s represents the current state, ac represents the action taken in the state, are weight coefficients, Indicates the thrust size, Indicates the speed from the current state to the next state, S indicates the straight-line distance from the current state to the target position, Indicates the difference between the straight-line distance from the current state to the target position and the straight-line distance from the target state to the target position.

6. The method for ocean data communication based on non-geostationary low-orbit small satellite according to claim 3, characterized in that: Based on the fixed orbits of all low-orbit satellites in the second low-orbit satellite set and the target position, the optimal trajectory of each low-orbit satellite when changing its orbit to the target position is determined under energy consumption constraints and time constraints, including: Based on the orbit differential equation of the low-orbit satellite based on the Gaussian perturbation equation and the continuous directional thrust direction angle function based on Fourier series fitting, an optimal trajectory control model based on energy consumption constraints and time constraints is established; The optimal solution of the optimal trajectory control model is solved according to the particle swarm optimization algorithm to obtain the optimal trajectory.

7. The method for ocean data communication based on a non-geostationary low-orbit small satellite according to claim 3, characterized in that: The collision probability of each low-orbit satellite is determined based on the optimal trajectory of each low-orbit satellite when it changes orbit to the target position, including: Obtain the operating positions and speeds of all other low-orbit satellites; Determine the spatial positions of multiple target time points during the operation process based on the operation position and operation speed, wherein the target time point is an arbitrarily selected time point during the time period when the low-orbit satellite changes its orbit to the target position; Connect the spatial positions of multiple time points to obtain the rough trajectories of multiple low-orbit satellites; Determine whether there is an intersection between the rough trajectories of the multiple low-orbit satellites and the optimal trajectory when the low-orbit satellite changes its orbit to the target position. If there is an intersection, mark the collision probability as the first collision probability; If it does not exist, the collision probability is marked as the second collision probability.

8. The method for ocean data communication based on non-geostationary low-orbit small satellite according to claim 1, characterized in that: When the privacy and timeliness requirements do not meet the preset conditions, the target low-orbit satellite is determined based on the location of the maritime satellite relay communication terminal; The target low-orbit satellite receives the uplink data sent by the maritime satellite relay communication terminal, and sends the data down to the receiver based on the inter-satellite link.

9. An electronic device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the steps of the method for far sea data communication based on a non-geostationary low-orbit small satellite as described in any one of claims 1 to 8.

10. A computer storage medium having computer instructions stored thereon, characterized in that: When the instruction is executed by the processor, the steps of the method for far sea data communication based on non-geostationary low-orbit small satellites described in any one of claims 1-8 are implemented.

Images