Ocean sea data communication method based on non-stationary orbit low-orbit moonlet

Abstract

The invention provides an open sea data communication method based on a non-stationary orbit low-orbit small satellite, which comprises the following steps: when a satellite network automatic management system receives a signaling of uplink data sent by a maritime satellite relay communication terminal in a target sea area range, analyzing the signaling to determine the privacy demand, the timeliness demand and the receiver information of information; when the privacy demand and the timeliness demand meet preset conditions, determining a target low-orbit satellite according to the position of the maritime satellite relay communication terminal and the receiver information; the target low-orbit satellite receives uplink data sent by the maritime satellite relay communication terminal and caches the uplink data; and when the target low-orbit satellite runs to the position covering the receiver, sending downlink data to the receiver. According to the method and the device, the data with high privacy requirement and low timeliness requirement are transmitted in a delayed manner through the low-orbit satellite until the position of the receiver, and the data are transmitted to the receiver, so that the frequency of intermediate transmission can be reduced, and the risk of data leakage can be reduced.

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 usually require satellites to transmit data through intersatellite links after receiving the data until it is sent to the target user's receiving end. 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 applicable to data with low timeliness requirements and high privacy requirements. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a method and device for high-sea 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 the 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 marine 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 receiver information of the information; when the privacy requirements and timeliness requirements meet preset conditions, the target low-orbit satellite is determined according to the position of the marine satellite relay communication terminal and the receiver information; the target low-orbit satellite receives the uplink data sent by the marine satellite relay communication terminal and caches the uplink data; when the target low-orbit satellite moves to a position covering the receiver, the downlink data is sent to the receiver.

[0007] Optionally, the target low-orbit satellite is determined according to the position of the maritime satellite relay communication terminal and the receiver information, 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, taking the low-orbit satellite as the target low-orbit satellite; if not, selecting a low-orbit satellite whose minimum distance between the signal coverage and the receiver position is less than a preset threshold from the first low-orbit satellite set 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; 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.

[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 a plurality of low-orbit satellites with a collision probability lower than a preset probability as a third low-orbit satellite set; and determining the comprehensive cost of energy consumption and time 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; 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.

[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 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 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; 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 according to 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 according to the operating position and the 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.

[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 receiver 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 implementation scheme 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 reduce 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 may be taught from the practice of the present invention. The objectives and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0023] Figure 3 It 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 described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can also be the internal connection of two components, it can be a wireless connection, or it can be a wired connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to 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 communicating data in the open sea based on a small non-geostationary low-orbit satellite. Figure 1 As shown, including:

[0028] S101, when the satellite network automation management system receives a signaling of uplink data sent by a maritime satellite relay communication terminal within the target sea area, the signaling is analyzed to determine the 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 according to 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 caches 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] Exemplarily, the automated management system of a satellite network refers to a system for managing and controlling a low-orbit satellite constellation, which can realize the automatic operation and management of satellites. In the automated management system of a satellite network, areas requiring key information protection can be divided in advance. In this embodiment, in order to realize the privacy communication of target offshore waters data, the target offshore waters can be included in the areas requiring key information protection in advance.

[0033] The marine satellite relay communication terminal is a device used to transmit data via satellite in a marine environment. It is usually installed on ships, buoys or other marine platforms, and can transmit the acquired data to shore base stations or other receiving terminals via satellite relays. When the satellite network automation management system receives the signaling of uplink data sent by the marine satellite relay communication terminal within the target sea area, the privacy and timeliness requirements of the information are determined by parsing the signaling. Since the signaling generally does not directly carry privacy and timeliness requirements, but can carry the encryption key or encryption algorithm identifier 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 does not carry priority information, it is considered that the information has a high privacy requirement and a low timeliness requirement, and meets the preset conditions.

[0034] For information with high privacy requirements and low timeliness requirements, if it is forwarded using intersatellite links, 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 covers 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, receiver's device type and function, and receiver's communication parameters. First, the receiver's location is obtained by parsing the receiver information carried in the signaling. Then, according to the location of the maritime satellite relay communication terminal and the receiver's location, it is determined whether there is a low-orbit satellite that covers both at the same time. If there is, the information transmission task is assigned to the low-orbit satellite. The ground control center usually maintains a user location database to record the location information of the user terminal device. When the receiver needs to receive information, the ground control center can guide the satellite to transmit the information to the location of the receiver according to the information in the database to complete the transmission of the information. If there is no information, a low-orbit satellite is randomly selected from the low-orbit satellites covering the location of the maritime satellite relay communication terminal, and the information transmission task is assigned to the low-orbit satellite. In order to ensure the transmission of data, the low-orbit satellite needs to change orbit according to the location of the receiver, including adjusting the satellite's orbital parameters, such as orbital inclination, orbital altitude, etc. Therefore, further, a low-orbit satellite with the lowest orbit change cost can be selected as the satellite for information transmission. This embodiment does not limit the method of selecting the target low-orbit satellite, and those skilled in the art can determine it 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 reduce 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, taking the low-orbit satellite as the target low-orbit satellite; if not, selecting a low-orbit satellite whose minimum distance between the signal coverage and the receiver's position is less than a preset threshold from the first low-orbit satellite set 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; 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] Exemplarily, low-orbit satellites generally operate in fixed orbits, and the signal coverage is calculated based on the fixed orbit path, orbital altitude, and satellite-to-ground distance. Determine whether the signal coverage of each low-orbit satellite orbiting the earth includes the receiver's location, and use all low-orbit satellites whose signal coverage includes the receiver's location as the first low-orbit satellite set. In the first low-orbit satellite set, determine whether there is a satellite whose coverage includes the receiver's location. If so, use the low-orbit satellite as the target low-orbit satellite to perform information transmission. If not, select a low-orbit satellite whose minimum distance between the signal coverage and the receiver's location is less than a preset threshold from the first low-orbit satellite set to obtain a second low-orbit satellite set. By using the distance between the signal coverage and the receiver's location, some low-orbit satellites that are closer are screened to reduce the amount of calculation of the subsequent orbit change cost.

[0039] The distance can be calculated by using the Euclidean distance formula applied to three-dimensional space. The minimum distance can be determined by taking each low-orbit satellite coverage trajectory as a space curve and the receiver position as a space point, and using calculus to find the minimum value from the space curve to the space 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 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 t value, and then we put it into the following distance formula to get the minimum distance d:

[0043]

[0044] All low-orbit satellites with minimum distances less than a preset threshold are taken as a second low-orbit satellite set, the minimum orbit change cost for changing the orbit to the target position during the operation of the low-orbit satellite is determined in the second low-orbit satellite set, and 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, 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 it changes its orbit to the target position under energy 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 it changes its orbit to the target position, and taking a plurality of low-orbit satellites with a collision probability lower than a preset probability as a third low-orbit satellite set; determining the comprehensive cost of energy and time for 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 of each low-orbit satellite when changing orbit to the target position under energy consumption constraints and time constraints can be determined by reinforcement learning. It is necessary to optimize the low-thrust orbit change strategy under the consideration of various orbital perturbations and the earth's shadow constraints to achieve the best time orbit transfer. The method of determining the optimal trajectory based on reinforcement learning is as follows:

[0047] According to the fixed 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 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 according to the current state and the target state.

[0048] Specifically, before using the reinforcement learning model to find strategies, we first build a satellite orbit environment model for offline learning. The process of building a satellite orbit environment model includes describing the satellite's initial position, velocity, target position, and the effects of various forces in space (such as the earth's gravity, atmospheric resistance, etc.) on the satellite's motion. Then, we define the state space, which can contain information such as the satellite's position (three-dimensional coordinates), velocity (three-dimensional velocity vector), and remaining fuel. These state variables can fully describe the state of the satellite in orbit. Then, we determine the actions that the satellite can take, that is, we build the action space, such as turning on or off thrusters in different directions to change the speed and direction. Each action will cause a change in the satellite's state.

[0049] The reward function is designed by considering energy consumption constraints and time constraints. For example, in order to meet the energy consumption constraint, energy consumption can be penalized; in order to meet the time constraint, a higher reward is given when the satellite reaches the target position within the specified time, and a lower reward or penalty is given when the time range 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] Then, a deep Q-network (DQN) is selected to initialize the algorithm with historical data or simulated data for training. An action is selected based on the current state. This action acts on the satellite orbit model to change the satellite state. The reward is calculated and the policy network is updated based on the new state and the predefined reward function. Information such as state, action, and reward is stored in the experience replay buffer. Data is sampled regularly from the experience replay buffer to update the parameters of the reinforcement learning algorithm to optimize the strategy so that the low-orbit satellite can choose better actions to obtain higher rewards.

[0053] This embodiment relies on the construction and training process of the above-mentioned reinforcement learning model. In the process of actually using the reinforcement learning model to obtain the optimal trajectory, the current state parameters include the current position, speed, energy consumption and other parameters of the low-orbit satellite. The current state parameters are input into the current policy network in the reinforcement learning model to determine the next state parameter set. The reward function and the next state parameter set are used to determine the rewards corresponding to multiple next states. The rewards corresponding to multiple next states are input into the value function to obtain multiple values, and 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 of the low-orbit satellite when changing orbit to the target position is determined. The value function is used to evaluate the expected value of the long-term return 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 ways: 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 according to the particle swarm optimization algorithm to obtain the optimal trajectory.

[0055] For example, during the orbit change process, the orbital elements of the satellite will change due to the applied thrust, and the perturbation caused by the thrust can be reflected by modifying the perturbation 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 is given below:

[0056]

[0057] Among them, a represents the semi-major axis, e represents the eccentricity, i represents the orbital inclination, γ represents the right ascension of the ascending node, ω represents the argument of perigee, z represents the true anomaly, n represents the mean motion, r represents the distance from the center of the satellite, E represents the eccentric anomaly, p is the semi-diameter, F 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 angle function based on Fourier series fitting is:

[0059]

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

[0061] According to the orbit differential equation of low-orbit satellite based on 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 constraint and time constraint 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 Represents the final actual satellite orbit parameters, P target_i represents the orbital parameters of the target location, 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 Fourier coefficients), 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] The embodiment of the present invention provides a method for high seas data communication based on a non-geostationary low-orbit small satellite. Through the above two methods, an optimal trajectory can be obtained, so as to facilitate subsequent evaluation of the optimal trajectory and select the optimal low-orbit satellite for data transmission.

[0069] As an optional implementation, the collision probability of each low-orbit satellite is determined according to 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 according to the operating position and the 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] Exemplarily, the current position and speed of the satellite are known, and the equation of motion of the satellite 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 according to 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 orbit. For the optimal trajectory of the orbit-changing satellite and the rough trajectories of other low-orbit satellites, it is necessary to check whether they intersect in the same time period.

[0071] When it is determined that there is an intersection, it is considered that the possibility of a collision is high 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 risk of collision is lower, 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] The embodiment of the present invention provides a method for high seas data communication based on a non-geostationary low-orbit small satellite. For multiple satellites, by comparing the trajectories of different satellites, their relative position relationship in space can be seen more clearly, so as to preliminarily judge whether there may be a collision risk, which provides a basis for subsequent detailed analysis. In addition, the target time point can be arbitrarily selected in 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] The embodiment of the present invention provides a method for communicating data in the open sea based on a non-geostationary low-orbit small satellite, which provides another channel for information that does not have high privacy requirements and has low timeliness requirements, and can ensure 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 used 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 the signaling of uplink data sent by the maritime satellite relay communication terminal within the target sea area;

[0077] The target low-orbit satellite determination module 202 is used to determine the target low-orbit satellite according to the position 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 cache module 203 is used for the target low-orbit satellite to receive the uplink data sent by the maritime satellite relay communication terminal and cache the uplink data;

[0079] The data sending module 204 is used 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] The memory 502 is a non-transitory computer-readable storage medium that can be used to store non-transitory software programs, non-transitory computer executable programs and modules, such as program instructions / modules corresponding to the method for communicating data over the open sea based on a non-geostationary low-orbit small satellite in an embodiment of the present invention. The processor executes various functional applications and data processing of the processor by running the non-transitory software programs, instructions and modules stored in the memory.

[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-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory 502 may optionally include a memory remotely arranged 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, the following is performed: Figure 1 The embodiment shown is a method for high seas data communication based on a small non-geostationary low-orbit satellite.

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

[0086] This embodiment also provides a computer storage medium, which stores computer executable instructions, and the computer executable instructions can execute the method for sea data communication based on a non-geostationary low-orbit small satellite in any of the above method embodiments. The storage medium can be a 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), etc.; the storage medium can also include a combination of the above 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 rather than to limit it. 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 sea 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 requirements 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 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, downlink data is sent to the receiver.

2. The method for sea 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 according to 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 whose signal coverage covers the receiver in the first low-orbit satellite set, and if so, use the low-orbit satellite as the target low-orbit satellite; If not present, a low-orbit satellite whose minimum distance between its signal coverage and the receiver's location is less than a preset threshold is selected from the first low-orbit satellite set to obtain a second low-orbit satellite set; Determine the minimum orbit change cost of the low-orbit satellite in the second low-orbit satellite set during the orbit change to the target position, wherein the target position is the position of the receiver covered by the signal coverage; 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 sea data communication based on a non-geostationary low-orbit small satellite according to claim 2, characterized in that: Determine the minimum orbit change cost of the low-orbit satellite in the second low-orbit satellite set to change the orbit to the target position during the operation, including: According to 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; Determine the collision probability of each low-orbit satellite according to the optimal trajectory of each low-orbit satellite when changing orbit to the target position, and use a plurality of low-orbit satellites with a collision probability 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 sea data communication based on a non-geostationary low-orbit small satellite according to claim 3, characterized in that: According to 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 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; According to 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 sea data communication based on non-geostationary low-orbit small satellite according to claim 4, characterized in that: The reward function is: 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.

6. The method for sea data communication based on a non-geostationary low-orbit small satellite according to claim 3, characterized in that: According to 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: According to the orbit differential equation of low-orbit satellite based on Gaussian perturbation equation and the continuous directional thrust 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 sea data communication based on a non-geostationary low-orbit small satellite according to claim 3, characterized in that: According to the optimal trajectory of each low-orbit satellite when changing its orbit to the target position, the collision probability of each low-orbit satellite is determined, including: Obtain the operating positions and speeds of all other low-orbit satellites; According to the running position and running speed, the spatial positions of multiple target time points in the running process are determined, wherein the target time point is a time point randomly selected 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; When it does not exist, the collision probability is marked as the second collision probability.

8. The method for sea data communication based on non-geostationary low-orbit small satellite according to claim 1, characterized in that: When the privacy requirements 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 high seas data communication based on a non-geostationary low-orbit small satellite as described in any one of claims 1-8 are implemented.

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