A method for analyzing node sensitivity that affects the degradation of the communication performance of a giant constellation

Abstract

A method for node sensitivity analysis affecting the degradation of the communication performance of a giant constellation. The present invention relates to the field of spacecraft system simulation. It solves the problem that in the prior art, there is a lack of a method for measuring the sensitivity of the constellation to changes in the number of satellites, which brings changes in performance such as communication delay. The method includes: reading the parameter values under different two-line element data segments according to the format of the two-line element data record and saving them to the SGP4 orbit model structure variable; dividing different sub-constellations within the giant constellation according to the orbital inclination or the semi-major axis of the orbit; setting that the satellites within each orbital plane form a routing domain, setting the gateway on / off condition, setting that the satellite nodes can communicate within the domain, and restricting the connectivity of the nodes in different domains; updating the connectivity between the nodes, outputting the on / off situation and delay between the nodes; and performing routing and outputting the routing result to complete the node sensitivity analysis. It is also applicable to the field of measuring the communication delay of giant constellations.

Description

Technical Field

[0001] The present invention relates to the technical field of spacecraft system simulation. Background Art

[0002] In the prior art, the method for parsing two-line element metadata of a constellation and realizing orbit recursion is as follows:

[0003] Read and identify the two-line element metadata of the constellation in a general format;

[0004] Initialize the model according to the SGP4 orbit model and the actual variables read;

[0005] Recursively calculate the orbit state according to the current time.

[0006] Partition the routing communication domain and gateways for the constellation configuration:

[0007] Determine the constellation configuration according to the six orbital elements of the satellites constituting the constellation: divide the sub-constellations according to the semi-major axis of the orbit and the orbital inclination, divide the orbital planes according to the right ascension of the ascending node, and sort the satellites in the orbital plane according to the argument of perigee + mean anomaly.

[0008] Let the satellites in the same orbital plane be divided into the same communication domain, and adjacent satellites (nodes) within the domain can communicate unconditionally.

[0009] Set the gateway nodes connected to each other on each orbital plane, and the connectivity between the gateway nodes is restricted by relative distance, relative velocity, earth occlusion, etc.

[0010] Find the path according to the node path table:

[0011] According to the above division, considering the connectivity within the domain, calculate the connectivity between the gateway nodes and generate a connectivity matrix. If it is not connected, the corresponding value is -1, and if it is connected, the corresponding value is the communication delay;

[0012] Use routing algorithms such as Dijkstra's algorithm to find all paths from the source node to the target node;

[0013] Record the requested bandwidth for each request and the remaining available bandwidth of the satellite nodes, and store the routing result;

[0014] Retrieve the routing result according to the request and display it visually in the software.

[0015] In summary, the current method for measuring the performance such as constellation communication delay is based on a fixed constellation that has been designed, and the number of satellites, position distribution, and relative phase relationship within the constellation remain basically unchanged. There is a lack of a way to evaluate the impact of dynamic processes such as the dynamic increase or decrease in the number of satellites and constellation reconstruction on performance such as communication delay. In addition, there is a lack of a method to measure the sensitivity of the constellation to changes in the number of satellites, which brings changes in performance such as communication delay. Summary of the Invention

[0016] In view of the problem in the prior art that there is a lack of a method for measuring the sensitivity of the constellation to changes in the number of satellites, which brings about changes in performance such as communication delay.

[0017] To solve the above technical problems, the present invention is realized through the following technical solutions:

[0018] Solution 1: The present invention proposes a node sensitivity analysis method for affecting the degradation of the communication performance of a large constellation. The node sensitivity analysis method includes the following steps:

[0019] Step 1: According to the format of the two-line element data record, read the parameter values under different two-line element segments and save them to the SGP4 orbit model structure variable.

[0020] Step 2: Initialize the orbit model of the SGP4 orbit model structure variable obtained in Step 1 to obtain the six orbital elements at the two-line element orbit epoch and the position and velocity in the J2000 coordinate system.

[0021] Step 3: Combine the simulation time and the simulation step size, calculate the time difference between the simulation time and the orbit epoch, substitute it into the SGP4 orbit model calculation function, and perform orbit propagation and data output.

[0022] Step 4: Divide different sub-constellations within the large constellation according to the orbital inclination or the semi-major axis of the orbit.

[0023] Step 5: Based on Step 4, divide different orbital planes within the sub-constellation according to the right ascension of the ascending node and the orbital inclination.

[0024] Step 6: Based on Step 5, determine the relative phase relationship of the satellites within the orbital plane according to the argument of latitude and perform sorting.

[0025] Step 7: Based on the orbital planes and sub-constellations divided in Step 6, set each satellite within the orbital plane to form a routing domain, set the gateway on-off condition, enable satellite nodes to communicate within the domain, and restrict the connectivity of nodes in different domains.

[0026] Step 8: According to the communication domain and link request set in Step 7, update the connectivity between nodes, and output the on-off situation and delay between nodes for reference in the sensitivity test method.

[0027] Step 9: Based on the connectivity between nodes calculated and output in Step 8, perform routing and output the routing result to complete the node sensitivity analysis.

[0028] Further, a preferred implementation is provided. The method for enabling satellite nodes to communicate within the domain and restricting the connectivity of nodes in different domains in Step 7 is as follows:

[0029] Step 7.1: Collect the two-line element data of the constellation to be measured, the predetermined time, and the step size.

[0030] Step 7.2: Based on the two-line element data of the constellation to be measured, the predetermined time, and the step size collected in Step 7.1, obtain the number of available links at the predetermined time.

[0031] Step 7.3: Calculate the set V1 of nodes with the shortest path edge number of 1 to the link source node and the set V2 of nodes with the shortest path edge number of 1 to the link target node among the available links at the predetermined time; determine whether the intersection V3 of the sets V1 and V2 is an empty set. If the set V3 is not an empty set, proceed to Step 7.4. If the set V3 is an empty set, repeat Step 7.3.

[0032] Step 7.4: Delete the intersection V3 described in Step 7.3, and calculate whether the link source node and the target node in each available link are connected. If there is a connection, increase the shortest path edge number of the adjacent nodes reaching the source and target nodes in Step 7.3, and repeat Step 7.4. If not, record the depth of the deletion this time and execute Step 7.5.

[0033] Step 7.5: If the number of available links is greater than the number of link requests, calculate the number of available links at the next moment, and simulate the constellation to be measured according to the depth of the deletion to obtain the number of link requests at the predetermined time.

[0034] Further, a preferred implementation is provided. The method for the nodes with the shortest path edge number of 1 of the source node and the target node in Step 7.3 to reach the next adjacent node is: both need to pass through at least one edge to reach the next adjacent node of the source node and the target node.

[0035] Further, a preferred implementation is provided. The selection method for increasing the shortest path edge number of the nodes reaching the source and target nodes in Step 7.4 is: if the current shortest path edge number is 1, remove the nodes with at least one edge number reaching the source and target nodes, then the remaining nodes have at least two edge numbers reaching the source and target nodes; that is, if the current shortest path edge number is k, remove the nodes with at least k edge numbers reaching the source and target nodes, then the remaining nodes have at least k + 1 edge numbers reaching the source and target nodes.

[0036] Further, a preferred implementation is provided. All links in the number of available links described in Step 7.2 intersect only at the source node and the target node, and the remaining nodes do not overlap.

[0037] Further, a preferred implementation is provided. The number of available links in Step 7.2 does not exceed the minimum value of the available node numbers of the source node and the target node.

[0038] Further, a preferred implementation is provided. The number of available links in Step 7.1 is expressed as: n ≤ min{nsource n destination}, where n is the number of available links, and n source is the number of nodes that can be connected to the source node, and n destination is the minimum value of the number of nodes that the target node can be connected to.

[0039] Solution 2: A computer-readable storage medium stores a computer program. When the computer program is executed by a processor, the steps of a method for analyzing node sensitivity that affects the degradation of the communication performance of a giant constellation described in any one of Solution 1 are implemented.

[0040] Solution 3: A computer device includes a memory and a processor. A computer program is stored in the memory. When the processor runs the computer program stored in the memory, the processor executes a method for analyzing node sensitivity that affects the degradation of the communication performance of a giant constellation described in any one of Solution 1.

[0041] Solution 4: A computer program product, as a computer program, when the computer program is executed, a method for analyzing node sensitivity that affects the degradation of the communication performance of a giant constellation described in Solution 1 is implemented.

[0042] The beneficial effects of the present invention are as follows:

[0043] To solve the problem that in the prior art, there is a lack of a method for measuring the sensitivity of the constellation to changes in the number of satellites, which brings changes in performance such as communication delay, the present invention proposes a method for analyzing node sensitivity that affects the degradation of the communication performance of a giant constellation. The method described in the present invention can be simple, general, intuitive, and effective without considering the configuration of the object.

[0044] The method for analyzing node sensitivity that affects the degradation of the communication performance of a giant constellation described in the present invention can meet the task requirements by restricting the depth of deletion and reduce the impact on other links.

[0045] The method for analyzing node sensitivity that affects the degradation of the communication performance of a giant constellation described in the present invention takes into account the impact of deleting satellite nodes on the link connection during the entire time period, ensuring that the links are basically not interrupted within the set time period.

[0046] The present invention is also applicable to the field of measuring performance such as communication delay of giant constellation communication. Description of the Drawings

[0047] Figure 1 It is a schematic framework diagram of a method for analyzing node sensitivity that affects the degradation of the communication performance of a giant constellation described in Embodiment 1.

[0048] Figure 2 It is a schematic diagram of a complete deletion example described in Embodiment 10.

[0049] (a) The left figure is a schematic diagram of the original connected situation without processing.

[0050] (a) The right figure is a schematic diagram of the connected situation after removing nodes 1 and 15 from the left figure in (a).

[0051] (b) The left figure is a schematic diagram of the connected situation after removing nodes 2 and 20 from the right figure in (a).

[0052] (b) The right figure is a schematic diagram of the connected situation after removing node 5 from the left figure in (b).

[0053] (c) The left figure is a schematic diagram obtained after removing nodes 9 and 21 from the right figure in (b).

[0054] (c) The right figure is a schematic diagram of the connected situation after removing node 22 from the left figure in (c).

[0055] (d) is a schematic diagram of the connected situation after removing nodes 8 and 16 from the right figure in (c).

[0056] Figure 3 It is a schematic diagram of the curve of the time delay varying with time caused only by the path length described in Embodiment Ten.

[0057] Figure 4 It is a schematic diagram of the curve of the total time delay considering the node time delay varying with time described in Embodiment Ten.

[0058] Figure 5 It is a schematic diagram of the curve of the communication time delay varying with time described in Embodiment Ten.

[0059] Figure 6 It is a schematic diagram of the flow of a node sensitivity analysis method for affecting the degradation of the communication performance of a giant constellation described in Embodiment Ten. Specific Embodiment

[0060] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application.

[0061] Embodiment One. This embodiment provides a node sensitivity analysis method for affecting the degradation of the communication performance of a giant constellation. The node sensitivity analysis method includes the following steps:

[0062] Step One: According to the format of the two-line metadata record, read the parameter values under different two-line metadata segments and save them to the SGP4 orbit model structure variable;

[0063] Step 2: Initialize the orbit model for the SGP4 orbit model structure variables described in Step 1 to obtain the six orbital elements at the two-line element orbital epoch and the position and velocity in the J2000 coordinate system;

[0064] Step 3: Combine the simulation time and the simulation step size, calculate the time difference between the simulation time and the orbital epoch, substitute it into the SGP4 orbit model calculation function, and perform orbit propagation and data output;

[0065] Step 4: Divide different sub-constellations within the giant constellation according to the orbital inclination or the semi-major axis of the orbit;

[0066] Step 5: Based on Step 4, divide different orbital planes within the sub-constellation according to the right ascension of the ascending node and the orbital inclination;

[0067] Step 6: Based on Step 5, determine the relative phase relationship of the satellites within the orbital plane according to the argument of latitude and sort them;

[0068] Step 7: Based on the orbital planes and sub-constellations divided in Step 6, set the satellites within each orbital plane to form a routing domain, set the gateway on / off conditions, enable satellite nodes to communicate within the domain, and restrict the connectivity of nodes in different domains;

[0069] Step 8: Update the connectivity between nodes according to the communication domain and link requests set in Step 7, and output the on / off status and delay between nodes for reference in the sensitivity test method;

[0070] Step 9: Based on the connectivity between output nodes calculated in Step 8, perform routing and output the routing results to complete the node sensitivity analysis.

[0071] Embodiment 2: This embodiment further limits a node sensitivity analysis method for affecting the degradation of the communication performance of a giant constellation described in Embodiment 1. The method for enabling satellite nodes to communicate within the domain and restricting the connectivity of nodes in different domains in Step 7 is as follows:

[0072] Step 7-1: Collect the two-line elements, the predetermined time, and the step size of the constellation to be measured;

[0073] Step 7-2: Based on the two-line elements, the predetermined time, and the step size of the constellation to be measured collected in Step 7-1, obtain the number of available links at the predetermined time;

[0074] Step 7-3: Calculate the set V1 of nodes with the shortest path edge number of 1 to the link source node and the set V2 of nodes with the shortest path edge number of 1 to the link destination node among the available links at the predetermined time; determine whether the intersection V3 of the sets V1 and V2 is an empty set. If the set V3 is non-empty, proceed to Step 7-4. If the set V3 is an empty set, repeat Step 7-3;

[0075] Step 74: Delete the intersection V3 described in step 73, calculate whether the link source node and the target node in each available link are connected, if there is connectivity, increase the number of shortest path edges to the adjacent nodes of the source and target nodes in step 73, and repeat step 74. If there is no connectivity, record the depth of this deletion and execute step 75;

[0076] Step 75: If the number of available links is greater than the number of link requests, the number of available links at the next moment is calculated, and the constellation to be tested is simulated according to the deletion depth to obtain the number of link requests at the predetermined moment.

[0077] Implementation method three: This implementation method is a further limitation of the node sensitivity analysis method that affects the communication performance degradation of the Giant Star Constellation described in implementation method two. The method for the node with the number of source nodes and the number of target nodes described in step seven-three whose shortest path edge number is 1 to reach the next adjacent node is that both nodes need to pass through at least one edge to reach the next adjacent node of the source node and the target node.

[0078] Implementation method 4. This implementation method is a further limitation of the node sensitivity analysis method that affects the degradation of the communication performance of the Giant Star Constellation described in implementation method 2. In step 74, the method for selecting the number of shortest path edges of adjacent nodes reaching the source and target nodes in step 73 is added as follows: if the current number of shortest path edges is 1, then remove the nodes with at least 1 edge number reaching the source and destination nodes, and the number of edges of the remaining nodes reaching the source and destination nodes is at least 2; that is, if the current number of shortest path edges is k, remove the nodes with at least k edge number reaching the source and destination nodes, and the number of edges of the remaining nodes reaching the source and destination nodes is at least k+1.

[0079] Implementation method five: This implementation method is a further limitation of the node sensitivity analysis method that affects the degradation of the communication performance of the Giant Star Constellation described in implementation method two. All the links in the number of available links described in step seven two only intersect at the source node and the target node, and the remaining nodes do not overlap.

[0080] Implementation method six: This implementation method is a further limitation of the node sensitivity analysis method that affects the degradation of the communication performance of the Giant Star Constellation described in implementation method five. In step seven-two, the number of available links does not exceed the minimum value of the number of available nodes of the source node and the target node.

[0081] Implementation 7. This implementation is a further limitation of the node sensitivity analysis method that affects the degradation of the communication performance of the giant star constellation described in Implementation 6. In step 7.1, the number of available links is expressed as: n≤min{n source n destination}, where n is the number of available links, n source is the number of nodes that can connect to the source node, n destinationis the minimum value of the number of nodes that can be connected to the target node.

[0082] Embodiment 8: A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method according to any one of Embodiments 1 to 6 are implemented.

[0083] Embodiment 9: A computer device includes a memory and a processor. A computer program is stored in the memory. When the processor runs the computer program stored in the memory, the processor executes the method according to any one of Embodiments 1 to 7.

[0084] Embodiment 10: A computer program product, as a computer program, when the computer program is executed, the method according to Embodiment 1 is implemented.

[0085] Embodiment 11: This embodiment proposes an example, and the example is used to explain Embodiments 1 to 9 above. The specific example is as follows:

[0086] See Figures 1 to 6 To illustrate this embodiment, the two-line metadata of the XL constellation on September 18, 2023, with a total of 4,729 satellites, is imported. To meet the requirements of adjacent connectivity of co-orbital links and position and velocity constraints of cross-orbital links, the satellites in the same orbital plane are divided into the same domain. According to the current Walker configuration of the XL constellation, there are 194 orbital planes, and 194 domains can be obtained. The number of domains included in each sub-constellation is shown in Table 1 below.

[0087] Table 1 XL Communication Domain Division

[0088] Sub-constellation Number of communication domains G-1 72 G-4 72 G-2 17 G-3 5 G-5 28

[0089] The following simplified assumptions and inferences are used in the simulation process:

[0090] Simplified Assumption 1: All nodes are allowed to connect to nodes in different domains. Since the cross-orbital forwarding settings of the XL constellation are unknown, to obtain all theoretically available links, it is considered that there is a possibility of establishing a link between cross-orbital satellites, that is, the nodes in each domain may establish a link with the nodes in adjacent different domains. Therefore, for any node, it is considered that it can act as a gateway and has the "permission" to connect to nodes in different domains.

[0091] Considering that in the process of link degradation simulation, there is no need for a quantitative description of the bandwidth and throughput of the XL constellation, but only a qualitative requirement that the throughput is reduced to 1 / 10 of the original. Therefore, the actual uplink and downlink bandwidths of the XL constellation are not used in the bandwidth setting. In this link simulation calculation, the bandwidth of the XL satellite is uniformly set to 10 Mb / s.

[0092] Simplified Assumption 2: The node bandwidths are consistent. Assume that the bandwidths of all nodes are the same, and the bandwidth differences between satellites are not considered.

[0093] Inference 2-1: All available links between the source and the destination only intersect at the source and destination nodes, and the other nodes do not coincide. To achieve the maximum transmission rate, when each link is established, the transmission rate of the nodes on this link is equal to the node bandwidth. Therefore, when establishing other available links between two places at the same time, the nodes on this link are unavailable due to full-rate transmission. Eventually, the available links are independent of each other, presenting as a cluster of curves that start from the source node, terminate at the target node, and have no intersection points with each other. For the convenience of subsequent description, the concept of "throughput" is replaced by "the number of available links".

[0094] Inference 2-2: The number of available links does not exceed the minimum value of the available node numbers of the source and destination nodes. According to the above assumption, since the available links have no intersection points with each other, it can be further concluded that the number of available links n must be less than the number of nodes n source that can be connected to the source node and the number of nodes n destination that can be connected to the target node. The minimum value is expressed as:

[0095] n ≤ min{n source n destination}

[0096] Therefore, in this assumed scenario, the number of available links is restricted by the source and destination coverage multiplicities. The simulation conditions are shown in Table 2 below.

[0097] Table 2 Details of Simulation Conditions

[0098]

[0099]

[0100] The time delay includes the cumulative path length delay and the cumulative node delay, and the relationship between these two delay components is very close. Figure 2 In, the left figure of Figure (a) is the original connected situation without processing. First, check whether there is a path that can be connected in one hop for T-KP, T-KK, and T-G. Nodes 1 and 15 meet the conditions. After removing nodes 1 and 15, the connected situation changes from the left figure of Figure (a) to the right figure of Figure (a). Then continue to check whether there is a 2-hop path for T-KP. And remove the nodes near the target node that are close to the 2-hop. Nodes 2 and 20 meet the conditions, and after removal, the left figure of Figure (b) can be obtained;

[0101] Figure (b) shows checking whether there is a 3-hop path in T-KP after removing nodes 2 and 20. Nodes close to the target node within 2 hops are removed, and node 5 meets the criteria. After removing node 5, the right figure of Figure (b) can be obtained. Then, check whether there is a 4-hop path in T-KP. Nodes close to the target node within 2 hops are removed, and nodes 9 and 21 meet the criteria.

[0102] The left figure of Figure (c) is obtained by removing nodes 9 and 21 from the right figure of Figure (b). Continue to check whether there is a 5-hop path in T-KP. Nodes close to the target node within 2 hops are removed, and node 22 meets the criteria. After removing node 22, the right figure of Figure (c) can be obtained. Then, check whether there is a 6-hop path in T-KP. Nodes close to the target node within 2 hops are removed, and nodes 8 and 16 meet the criteria.

[0103] The left figure of Figure (d) is the same as the right figure of Figure (c). The right figure of Figure (d) shows the connectivity after removing nodes 8 and 16. Check whether there is a 7-hop path in T-KP. It is found that there is no connected path in T-KP, so this operation is withdrawn and the connectivity of the left figure of Figure (d) is retained. Similarly, continue to screen paths such as T-G and T-KK. If the deletion of multiple links has been completed, the screening for the next time step is carried out.

[0104] For the processing of the connectivity corresponding to different time steps, before removing nodes at each step, the connectivity between two locations is also checked within other steps to determine whether this operation is retained.

[0105] See Figure 3 、 Figure 4 as shown, where Figure 3 、 Figure 4 are the delay-time curves caused only by considering the path length and the total delay-time curve considering the node delay respectively. Among them, Figures 3 to 5 G is the time delay change curve of the shortest path from T to G, KK (Kunsan) is the time delay change curve of the shortest path from T to KK, KP (Cadena) is the time delay change curve of the shortest path from T to KP, G-average is the average value of curve G within the time period, KK-average is the average value of the time delay for connecting KK within the time period, and KP-average is the average value of the curve for connecting KP within the time period. They can be used to measure the instantaneous fluctuation and average state of the communication delay. It is easy to find that the mean delay changes with the distance of the communication. Along with the operation of the constellation, there is a small range change in the link length, and thus a small amplitude fluctuation in the delay. The total delay is based on the path delay and adds the node processing delay according to the number of hops of the link. The delay added for each node is 3.09 ms.

[0106] The effects obtained using this clearing method are as follows:

[0107] Request Latency Variation before and after Clearing in Table 3

[0108] Link request Pre-clear delay (ms) Post-clear delay (ms) Delay multiple T-G 17.1 89 5.2 T-KK 8.78 59.9 6.82 T-KP 6.6 56.4 8.54

[0109] It can be seen that the multiplication factor of the increased latency meets the requirements. The latency fluctuation is relatively large, which may be caused by the limitation that the deletion depth n ≤ 10. Since the number of hops of the T-G link fluctuates between 2 and 3, with an average value of 2.3, the number of hops after degradation must reach at least 10, so the limitation of n ≤ 10 is obtained. In addition, it can be seen that the trend directions of the three links remain relatively consistent during some periods. This is because the mutual occupation problem between requests of each link (T-G, T-KK, T-KP) is not considered. The calculation process only ensures that the multiple paths within a single request do not overlap. Therefore, the similar trend is caused by the partial overlap of the paths of the three requests.

[0110] Figure 1 Any process or method description shown in the flowcharts described herein or otherwise described herein can be understood to represent a module, segment, or portion of code that includes one or more executable instructions for implementing a customized logical function or process. The scope of the preferred embodiments of the present invention includes additional implementations, where the functions may be performed in an order different from that shown or discussed, including in a substantially simultaneous manner or in a reverse order according to the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention belong. The logic and / or steps represented in the flowcharts or otherwise described herein illustrate the possible architectures, functions, and operations of the apparatus and methods according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagram may represent a module, a segment of a program, or a portion of code that includes one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in an order different from that marked in the drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, and they may sometimes be executed in a reverse order, depending on the functions involved. It should also be noted that each block in the block diagram or flowchart, and combinations of blocks in the block diagram or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or operations, or by a combination of dedicated hardware and computer instructions. For example, a definite sequence list that can be considered as executable instructions for implementing a logical function can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or in combination with these instruction execution systems, apparatus, or devices.

[0111] As for the embodiments of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection part (electronic device) having one or N wirings, a portable computer disk cartridge (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpretation, or, if necessary, other suitable processing, and then storing it in a computer memory. It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or a combination of the following techniques well-known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application-specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0112] Those skilled in the art can understand that the above are only the preferred embodiments of the present invention. The features recited in each embodiment and / or claim of the present disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly recited in the present disclosure. It is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recited in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

[0113] Although the preferred embodiments of the present invention have been described, additional changes and modifications can be made to these embodiments by those skilled in the art once they learn of the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art can make various changes and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A node sensitivity analysis method that affects the degradation of the communication performance of the giant star constellation, characterized in that: The method comprises the following steps: Step 1: Read the parameter values ​​under different double-line metadata segments according to the format of the double-line metadata record and save them to the SGP4 orbit model structure variable; Step 2: Initialize the orbit model of the SGP4 orbit model structure variable described in step 1 to obtain the six orbit elements under the double-row metadata orbit epoch and the position and velocity under the J2000 coordinate system; Step 3: Combine the simulation time and simulation step length to calculate the time difference between the simulation time and the orbit epoch, substitute it into the SGP4 orbit model calculation function, and perform orbit recursion and data output; Step 4: Divide the giant constellation into different sub-constellations according to the orbital inclination or the orbital semi-major axis; Step 5: based on step 4, divide different orbital planes within the sub-constellation according to the right ascension of the ascending node and the orbital inclination; Step 6: Based on step 5, determine the relative phase relationship of the satellites in the orbital plane according to the latitude argument, and sort them; Step 7: Based on the orbital plane and sub-constellation divided in step 6, set the satellites in each orbital plane to form a routing domain, set the gateway on / off conditions, set the satellite nodes to be able to communicate within the domain, and limit the connectivity of nodes in different domains; Step 8: According to the communication domain and link request set in step 7, update the connectivity between nodes, output the on / off status and delay between nodes, and use it as a reference for the sensitivity test method; Step 9: Based on the connectivity between the output nodes calculated in step 8, path finding is performed and the path finding result is output to complete the node sensitivity analysis; In step 7, the satellite nodes are set to be able to communicate within the domain. The method of limiting the connectivity of nodes in different domains is as follows: Step 71: Collect the double-row metadata, scheduled time and step length of the constellation to be measured; Step 72: based on the dual-row metadata of the constellation to be measured, the scheduled time and the step length collected in step 71, obtain the number of available links at the scheduled time; Step 73: Calculate the set V1 of nodes whose shortest path edge number to the link source node is 1 and the set V2 of nodes whose shortest path edge number to the link target node is 1 among the available links at the predetermined time; determine whether the intersection V3 of the sets V1 and V2 is an empty set; if the set V3 is not an empty set, proceed to S4; if the set V3 is an empty set, repeat S3; Step 74: Delete the intersection V3 described in step 73, calculate whether the link source node and the target node in each available link are connected, if there is connectivity, increase the number of shortest path edges to the adjacent nodes of the source and target nodes in step 73, and repeat step 74. If there is no connectivity, record the depth of this deletion and execute step 75; Step 75: If the number of available links is greater than the number of link requests, the number of available links at the next moment is calculated, and the constellation to be tested is simulated according to the deletion depth to obtain the number of link requests at the predetermined moment.

2. The node sensitivity analysis method affecting the degradation of the communication performance of the giant star constellation according to claim 1 is characterized in that: The method for the node with the shortest path edge number of the source node number and the target node number as described in step 7-3 to reach the next adjacent node is: both need to pass through at least one edge to reach the next adjacent node of the source node and the target node.

3. The node sensitivity analysis method affecting the degradation of the communication performance of the giant star according to claim 1 is characterized in that: The method for selecting the number of shortest path edges of the adjacent nodes reaching the source and target nodes in step 73 in step 74 is as follows: if the current number of shortest path edges is 1, then remove the nodes with at least 1 edge reaching the source and target nodes, and the number of edges of the remaining nodes reaching the source and target nodes is at least 2; that is, if the current number of shortest path edges is k, remove the nodes with at least k edge reaching the source and target nodes, and the number of edges of the remaining nodes reaching the source and target nodes is at least k+1.

4. The node sensitivity analysis method affecting the degradation of the communication performance of the giant star according to claim 1 is characterized in that: All links in the number of available links described in step 72 intersect only at the source node and the target node, and the remaining nodes do not overlap.

5. The node sensitivity analysis method affecting the degradation of the communication performance of the giant star according to claim 4 is characterized in that: In step 72, the number of available links does not exceed the minimum value of the number of available nodes of the source node and the target node.

6. The node sensitivity analysis method affecting the degradation of the communication performance of the giant star according to claim 5 is characterized in that: The number of available links in step 71 is expressed as: n≤min{n source n destination }, where n is the number of available links, n source is the number of nodes that can connect to the source node, n destination is the minimum number of nodes that the target node can connect to.

7. A computer-readable storage medium, characterized in that The computer-readable storage medium is used to store a computer program, and the computer program executes the method according to any one of claims 1 to 6.

8. A computer device comprising a memory and a processor, characterized in that A computer program is stored in the memory. When the processor runs the computer program stored in the memory, the processor implements the method according to any one of claims 1 to 6.

9. A computer program product, being a computer program, characterized in that When the computer program is executed, the method of claim 1 is implemented.

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