A method for analyzing inter-giant constellation compatibility based on a Spark architecture

Abstract

This invention discloses a method for compatibility analysis between mega-constellations based on the Spark architecture, belonging to the field of satellite system compatibility analysis. The technical problem this invention aims to solve is to provide a method for compatibility analysis between mega-constellations based on the Spark architecture. This method optimizes the compatibility analysis process, achieves functional decoupling, improves algorithm parallelism, and utilizes the Spark architecture to perform parallel computation, thereby improving computational efficiency and effectively reducing overall computation time. Key technical points: A parallel interference analysis architecture for mega-constellations is constructed. Based on the set simulation start and end times and simulation step size, the interference analysis process is divided into multiple time slices. Within each time slice, the interference analysis process is decomposed into orbit extrapolation, satellite and earth station visibility calculation, earth station satellite selection, interference link and interfered link visibility calculation, and interference index calculation. Parallel interference analysis based on the Spark architecture decouples the mega-constellation interference analysis process according to time and functional dimensions, forming separate modules. Action operators are added to the interference analysis process. These action operators are added at the following locations: the end position of each time slice calculation, the end position of orbit extrapolation, the end position of visibility calculation, the end position of earth station satellite selection, the end position of interference link and interfered link visibility calculation, and the end position of interference index calculation.

Description

Technical Field

[0001] This invention belongs to the field of inter-satellite system compatibility analysis, and specifically relates to a method for inter-satellite constellation compatibility analysis based on the Spark architecture. Background Technology

[0002] The number and scale of planned mega-LEO constellations are constantly increasing internationally. Starlink plans for 42,000 satellites, with nearly 7,000 already launched; OneWeb has deployed over 400 satellites and plans to expand to 6,372. Other mega-LEO constellations such as TeleSat, Boing V-band, and Kuiper are also continuously expanding, leading to increasingly prominent interference problems between these constellations. Interference analysis faces challenges such as the large scale of mega-LEO constellations, complex interference scenarios, and high computational demands. Existing interference analysis systems are all single-machine systems with limited computing resources, low efficiency, and long processing times, failing to meet the timeliness requirements of interference analysis. Summary of the Invention

[0003] The technical problem to be solved by this invention is to provide a compatibility analysis method for giant constellations based on the Spark architecture, which can optimize the compatibility analysis process, complete functional decoupling, improve the parallelism of the algorithm, and use the Spark architecture to complete parallel computing, thereby improving computing efficiency and effectively reducing the overall computing time.

[0004] The present invention adopts the following technical solution:

[0005] An improved method for compatibility analysis between giant constellations based on Spark architecture includes the following steps:

[0006] Step 1: Build a parallel interference analysis architecture between giant constellations:

[0007] Based on the set simulation start and end times and simulation step size, the interference analysis process is divided into multiple time slices. Within each time slice, the interference analysis process is decomposed into five sub-processes: orbit simulation, satellite and earth station visibility calculation, earth station satellite selection, interference link and interfered link visibility calculation, and interference index calculation.

[0008] Step 2, Parallel interference analysis based on Spark architecture:

[0009] Step 21: Decouple the interference analysis process between mega-constellations according to the time dimension and the functional dimension to form a separate module; the functional dimension includes five functions: orbit extrapolation, satellite and earth station visibility calculation, earth station satellite selection, interference link and interfered link visibility calculation, and interference index calculation.

[0010] Step 22: Add action operators to the interference analysis process and divide the interference analysis process into five jobs;

[0011] The action operator is added at the following positions: the end position of calculation for each time slice, the end position of orbit extrapolation, the end position of visibility calculation, the end position of Earth station satellite selection, the end position of visibility calculation for interfering links and interfered links, and the end position of interference index calculation.

[0012] The implementation method for each job is as follows:

[0013] Job-1, Orbit Deduction: Using an orbital model to deduce the satellite's orbit and calculate the satellite's location in the current time slice;

[0014] Job-2, Visibility Calculation: Based on the earth station's location and the satellite locations derived from Job-1, analyze whether the satellites and the earth station are visible to each other in the current time slice.

[0015] Calculate the distance D between the satellite and the earth station:

[0016]

[0017] In the above formula, x1, y1, and z1 are the position vectors of the satellite, and x2, y2, and z2 are the position vectors of the earth station.

[0018] The distance R1 from the satellite to the Earth's center is: The distance R2 from the Earth station to the Earth's center is: The distance D from the satellite and earth station to the horizon i :

[0019]

[0020] In the above formula, R e The radius of the Earth;

[0021] When the distance D between the satellite and the earth station is less than D1+D2, the satellite and the earth station are visible to each other.

[0022] Job-3, Earth Station Satellite Selection: The Earth Station selects a satellite from the visible stars to establish a link based on the satellite selection strategy;

[0023] Job-4, Visibility calculation of the interfering link and the interfered link: After both the earth station of the interfering system and the earth station of the interfered system have completed satellite selection and link establishment through job-3, the visibility calculation method of job-2 is used to analyze whether the transmitter of the interfering system and the receiver of the interfered system are visible. If they are visible, there is interference in that time slice, and job-5 calculation is required.

[0024] Job-5, Interference Index Calculation;

[0025] Step 23: The Spark architecture automatically identifies whether the RDD inside the job has wide or narrow dependencies. If a wide dependency is identified, the job is divided into stages, thus automatically dividing the job into stages based on the wide dependency.

[0026] Step 24: Divide each stage into corresponding tasks according to the number of times each stage needs to be computed in the Spark architecture;

[0027] Step 25: Distribute each Task to the designated Executor for execution.

[0028] Furthermore, in job-1, the orbital models for orbital derivation include J2, SGP4, and SDP4.

[0029] Furthermore, in job-3, the satellite selection strategy for Earth station satellites includes the longest tracking time, the maximum communication angle, the shortest communication distance, and the maximum separation angle.

[0030] Furthermore, in job-5, the interference indicators for interference index calculation include C / N, C / I, I / N, C / (I+N), ΔT / T, PFD, and EPFD.

[0031] Furthermore, in step 24, the number of tasks for orbit simulation equals the number of satellites requiring orbit simulation, which equals the number of satellites in the interfering system plus the number of satellites in the interfered system; the number of tasks for satellite-to-earth-station visibility calculation equals the number of earth stations in the interfering system multiplied by the number of satellites in the interfering system plus the number of earth stations in the interfered system multiplied by the number of satellites in the interfered system; the number of tasks for earth station satellite selection equals the number of earth stations in the interfering system plus the number of earth stations in the interfered system; the number of tasks for interfering link-to-interfered link visibility calculation equals the number of interfering links multiplied by the number of interfered links; and the number of tasks for interfering index calculation equals the number of visible points at the receiver of the interfering link and the transmitter of the interfered link.

[0032] The beneficial effects of this invention are:

[0033] The method disclosed in this invention designs two dimensions of parallel acceleration for the compatibility analysis algorithm, optimizes the compatibility analysis process, completes functional decoupling, improves the parallelism of the compatibility analysis algorithm, and maps it to the Spark architecture that can perform parallel computing. By using the Spark architecture to complete parallel computing, the efficiency of interference analysis computing and the utilization rate of computing resources are greatly improved, providing strong support for frequency track resource application, coordination and maintenance. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the architecture for parallel interference analysis between giant constellations;

[0035] Figure 2 This is a flowchart illustrating the process of Spark implementing parallel computing;

[0036] Figure 3 This is a diagram illustrating the visibility between the satellite and the earth station;

[0037] Figure 4 This is a diagram showing the visibility of the interfering link and the interfered link. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0039] Example 1 addresses the challenges of complex interference scenarios and high computational complexity and time consumption in interference analysis between giant low-Earth orbit constellations. This example discloses a compatibility analysis method for giant constellations based on the Spark architecture, comprising the following steps:

[0040] Step 1: Build a parallel interference analysis architecture between giant constellations:

[0041] like Figure 1 As shown, to improve the efficiency of inter-constellation interference analysis and reduce computation time, parallel computation of the inter-constellation interference analysis task is implemented from two dimensions:

[0042] (1) Parallel computation between different time slices:

[0043] Based on the set simulation start and end times and simulation step size, the interference analysis process is divided into multiple time slices. The calculations between time slices do not affect each other, and the calculation tasks of different time slices can be distributed to different computing nodes for parallel computing through Spark.

[0044] (2) Parallel computation within time slices:

[0045] Within a time slice, the interference analysis process is broken down into five sub-processes: orbit extrapolation, satellite and earth station visibility calculation, earth station satellite selection, interference link and interfered link visibility calculation, and interference index calculation.

[0046] Each subprocess requires multiple calculations, therefore parallel computation is possible within each subprocess. Taking orbit extrapolation as an example, the number of orbit extrapolations required within a single time slice is equal to the total number of satellites. Therefore, the number of orbit extrapolations that can be parallelized is min(total number of satellites, number of parallel threads allocated to this time slice by the Spark architecture).

[0047] Step 2, Parallel interference analysis based on Spark architecture:

[0048] like Figure 2 As shown, the interference analysis process is first divided into multiple jobs by using the action operator as the boundary; within each job, the job is divided into multiple stages by analyzing the dependencies between RDDs; finally, the stages are divided into tasks, and tasks can be executed in parallel.

[0049] A job is a parallel computation consisting of multiple tasks, often triggered by Spark Action operators. Multiple jobs are often generated within an application.

[0050] RDD: Resilient Distributed Datasets;

[0051] stage: Each job is split into multiple tasks, forming a TaskSet named stage;

[0052] task: A unit of work that is sent to an Executor;

[0053] Step 21: Decouple the interference analysis process between mega-constellations according to the time dimension and the functional dimension to form a separate module. Parallel computing is performed through Spark, which greatly speeds up the simulation. The time dimension ensures that the interference analysis process between different time slices does not interfere with each other. The functional dimension includes five functions: orbit extrapolation, satellite and earth station visibility calculation, earth station satellite selection, interference link and interfered link visibility calculation, and interference index calculation.

[0054] Step 22: Add action operators to the interference analysis process and divide the interference analysis process into five jobs;

[0055] The action operator is added at the following positions: the end position of calculation for each time slice, the end position of orbit extrapolation, the end position of visibility calculation, the end position of Earth station satellite selection, the end position of visibility calculation for interfering links and interfered links, and the end position of interference index calculation.

[0056] The implementation method for each job is as follows:

[0057] Job-1, Orbit Deduction: Using orbital models such as J2, SGP4 / SDP4, etc., the satellite orbit is deduced to calculate the satellite's position in the current time slice;

[0058] Job-2, Visibility Calculation: Based on the earth station's location and the satellite locations derived from Job-1, analyze whether the satellites and the earth station are visible to each other in the current time slice.

[0059] Calculate the distance D between the satellite and the earth station:

[0060]

[0061] In the above formula, x1, y1, and z1 are the position vectors of the satellite, and x2, y2, and z2 are the position vectors of the earth station.

[0062] The distance R1 from the satellite to the Earth's center is: The distance R2 from the Earth station to the Earth's center is: The distance D from the satellite and earth station to the horizon i :

[0063]

[0064] In the above formula, R e The radius of the Earth;

[0065] like Figure 3 As shown, when the distance D between the satellite and the earth station is less than D1+D2, that is, D<D1+D2, the satellite and the earth station are visible to each other.

[0066] Job-3, Earth Station Satellite Selection: The Earth Station selects a satellite from the visible stars to establish a link based on the satellite selection / link establishment strategy. The satellite selection strategy includes the longest tracking time, the maximum communication angle, the shortest communication distance, the maximum separation angle, etc.

[0067] Job-4, Visibility calculation of interfering and interfered links: (e.g.) Figure 4 As shown, after both the earth station of the jamming system and the earth station of the jammed system complete satellite selection and link establishment through job-3, the visibility calculation method of job-2 is used to analyze whether the transmitter of the jamming system and the receiver of the jammed system are visible. If they are visible, there is interference in that time slice, and job-5 calculation is required.

[0068] If system A interferes with system B in a scenario, then system A is the interfering system and system B is the interfered system.

[0069] Job-5, Interference Indicator Calculation: Calculate interference indicators specified by ITU, such as C / N, C / I, I / N, C / (I+N), △T / T, PFD, and EPFD, according to requirements;

[0070] Step 23: The Spark architecture automatically identifies whether the RDD inside the job has wide or narrow dependencies. If a wide dependency is identified, the job is divided into stages, thus automatically dividing the job into stages based on the wide dependency.

[0071] Step 24: Divide each stage into corresponding tasks according to the number of times each stage needs to be computed in the Spark architecture;

[0072] The number of tasks for orbit extrapolation equals the number of satellites requiring orbit extrapolation, which in turn equals the number of satellites in the jamming system plus the number of satellites in the jammed system. The number of tasks for satellite-to-earth-station visibility calculation equals the number of earth stations in the jamming system multiplied by the number of satellites in the jamming system, plus the number of earth stations in the jammed system multiplied by the number of satellites in the jammed system. The number of tasks for earth station satellite selection equals the number of earth stations in the jamming system plus the number of earth stations in the jammed system. The number of tasks for calculating the visibility of jamming links and jammed links equals the number of jamming links multiplied by the number of jammed links. The number of tasks for calculating interference indicators equals the number of visible sources at the receivers of the jamming links and the transmitters of the jammed links.

[0073] Step 25: Distribute each Task to the designated Executor for execution.

[0074] Executor: A process that runs on a worker node for a given application.

[0075] The Starlink and OneWeb constellations are selected as the interference simulation objects to analyze the downlink interference of the Starlink constellation to the OneWeb constellation. The simulation period is 1 day and the simulation step size is 1 second. The orbital parameters of the OneWeb constellation are shown in Table 1 below.

[0076] Table 1: Oneweb Constellation Orbit Parameters

[0077]

[0078] The system parameters of Oneweb constellation are shown in Table 2 below.

[0079] Table 2: Oneweb Constellation System Parameters

[0080] parameter numerical values Satellite transmitting antenna peak gain / dBi 28 Satellite transmitting antenna half-power beamwidth / (°) 4.9 Ground station receiving antenna peak gain / dBi 38 Ground station receiving antenna half-power beamwidth / (°) 1.6 Satellite transmit power / dBW 3 Communication frequency / GHz 17.8 Communication bandwidth / MHz 250 System noise temperature / K 300 Ground station location / (°E, °N) (120,40)

[0081] The orbital parameters of the Starlink constellation are shown in Table 3 below.

[0082] Table 3: Starlink constellation orbital parameters

[0083]

[0084] The system parameters of the Starlink constellation are shown in Table 4 below.

[0085] Table 4: Starlink Constellation System Parameters

[0086]

[0087] (1) Based on the designed parallel dimension, the parallel interference analysis process between giant constellations is decoupled, including the time dimension and the functional dimension:

[0088] 1) Parallel computation in the time dimension:

[0089] In this embodiment, the simulation period is 1 day, the simulation step size is 1 second, and it can be divided into 24*60*60=86400 time slices. Each time slice can be allocated corresponding computing resources by the Spark cluster for parallel computing.

[0090] 2) Parallel computing at the functional level:

[0091] The functional dimensions are decoupled into functions such as orbit extrapolation, visibility calculation, earth station satellite selection, visibility calculation of interfering links and interfered links, and interference index calculation. Each function corresponds to a job, and parallel computing can be performed within each job.

[0092] Job-1, Orbit Simulation: Using the J2 and SGP4 / SDP4 orbit models, the satellite trajectory is simulated, and the satellite's position at each moment is calculated;

[0093] In this scenario, there are 1969 + 11908 = 13877 satellites. Therefore, 13877 orbit simulations need to be repeated within each time slice. The orbit simulations of different satellites are independent of each other and can be performed in parallel by allocating corresponding computing resources from the Spark cluster.

[0094] Job-2, Visibility Calculation: Calculate whether the satellite and the earth station are visible to each other using the earth station's location and the satellite's location obtained in job-1.

[0095] In this scenario, the number of visibility calculations required within each time slice is 1969×1+11908×5=61509. The visibility between different satellites and earth stations is independent of each other, and the Spark cluster can allocate corresponding computing resources for parallel computation.

[0096] Job-3, Earth Station Satellite Selection: Based on the satellite selection strategy, the Earth Station selects one visible satellite from the satellites obtained in Job-2 for link establishment. Specific satellite selection strategies include: longest tracking time, maximum communication angle, shortest communication distance, and maximum separation angle.

[0097] Assuming that after calculation 2), the number of satellites visible to the earth station accounts for 10% of the total number of satellites, then 1969×1%×1+11908×1%×5=615 times are required at a single moment. The satellite selection calculations between different earth stations and satellites are independent of each other and can be performed in parallel by allocating corresponding computing resources by the Spark cluster.

[0098] Job-4, Visibility Calculation of Interference Link and Interference Link: After both the earth stations of the interfering system and the interfered system have completed satellite selection and link establishment through job-3, the visibility calculation method introduced in job-2 is used to analyze whether the transmitter of the interfering system and the receiver of the interfered system are visible to each other.

[0099] Since only 5 interfering links and 1 interfered link were constructed in this scenario, only 5 visibility analyses are needed. The visibility between different satellites and earth stations is independent of each other, and the Spark cluster can allocate corresponding computing resources for parallel computing.

[0100] Job-5, Interference Indicator Calculation: Calculate interference indicators as specified by ITU, such as C / N, C / I, I / N, C / (I+N), △T / T, PFD, and EPFD, according to requirements.

[0101] Since this scenario involves 5 interfering links and 1 interfered link, M single-ingress interference calculations and 1 lumped interference calculation are required (0 ≤ M ≤ 5). The M single-ingress interferences are independent of each other and can be computed in parallel by allocating corresponding computing resources from the Spark cluster.

[0102] (2) Spark automatically divides a job into stages by analyzing the dependencies of RDDs within the job and using wide dependencies as boundaries.

[0103] (3) Divide each stage into corresponding tasks according to the number of times each stage needs to be computed in the Spark architecture. (4) Distribute each task to the specified Executor for execution.

Claims

1. A method for compatibility analysis between giant constellations based on Spark architecture, characterized in that, Includes the following steps: Step 1: Build a parallel interference analysis architecture between giant constellations: Based on the set simulation start and end times and simulation step size, the interference analysis process is divided into multiple time slices. Within each time slice, the interference analysis process is decomposed into five sub-processes: orbit simulation, satellite and earth station visibility calculation, earth station satellite selection, interference link and interfered link visibility calculation, and interference index calculation. Step 2, Parallel interference analysis based on Spark architecture: Step 21: Decouple the interference analysis process between mega-constellations according to the time dimension and the functional dimension to form a separate module; the functional dimension includes five functions: orbit extrapolation, satellite and earth station visibility calculation, earth station satellite selection, interference link and interfered link visibility calculation, and interference index calculation. Step 22: Add action operators to the interference analysis process and divide the interference analysis process into five jobs; The action operator is added at the following positions: the end position of calculation for each time slice, the end position of orbit extrapolation, the end position of visibility calculation, the end position of Earth station satellite selection, the end position of visibility calculation for interfering links and interfered links, and the end position of interference index calculation. The implementation method for each job is as follows: Job-1, Orbit Deduction: Use the orbit model to deduce the satellite's orbit and calculate the satellite's position in the current time slice; Job-2, Visibility Calculation: Based on the earth station's location and the satellite locations derived from Job-1, analyze whether the satellites and the earth station are visible to each other in the current time slice. Calculate the distance D between the satellite and the earth station: In the above formula, x1, y1, and z1 are the position vectors of the satellite, and x2, y2, and z2 are the position vectors of the earth station. The distance R1 from the satellite to the Earth's center is: The distance R2 from the Earth station to the Earth's center is: The distance D from the satellite and earth station to the horizon i : In the above formula, R e The radius of the Earth; When the distance D between the satellite and the earth station is less than D1+D2, the satellite and the earth station are visible to each other. Job-3, Earth Station Satellite Selection: The Earth Station selects a satellite from the visible stars to establish a link based on the satellite selection strategy; Job-4, Visibility calculation of the interfering link and the interfered link: After both the earth station of the interfering system and the earth station of the interfered system have completed satellite selection and link establishment through job-3, the visibility calculation method of job-2 is used to analyze whether the transmitter of the interfering system and the receiver of the interfered system are visible. If they are visible, there is interference in that time slice, and job-5 calculation is required. Job-5, Interference Index Calculation; Step 23: The Spark architecture automatically identifies whether the RDD inside the job has wide or narrow dependencies. If a wide dependency is identified, the job is divided into stages, thus automatically dividing the job into stages based on the wide dependency. Step 24: Divide each stage into corresponding tasks according to the number of times each stage needs to be computed in the Spark architecture; Step 25: Distribute each Task to the designated Executor for execution.

2. The method for compatibility analysis between giant constellations based on Spark architecture according to claim 1, characterized in that: Job-1, the orbital models for orbital derivation include J2, SGP4 and SDP4.

3. The method for compatibility analysis between giant constellations based on Spark architecture according to claim 1, characterized in that: Job-3, the satellite selection strategy for Earth stations includes the longest tracking time, the maximum communication angle, the shortest communication distance, and the maximum separation angle.

4. The method for compatibility analysis between giant constellations based on Spark architecture according to claim 1, characterized in that: Job-5, the interference indices for interference index calculation include C / N, C / I, I / N, C / (I+N), ΔT / T, PFD, and EPFD.

5. The method for compatibility analysis between giant constellations based on Spark architecture according to claim 1, characterized in that: In step 24, the number of tasks for orbit simulation equals the number of satellites requiring orbit simulation, which is equal to the number of satellites in the interfering system plus the number of satellites in the interfered system; the number of tasks for satellite-to-earth-station visibility calculation equals the number of earth stations in the interfering system multiplied by the number of satellites in the interfering system plus the number of earth stations in the interfered system multiplied by the number of satellites in the interfered system; the number of tasks for earth station satellite selection equals the number of earth stations in the interfering system plus the number of earth stations in the interfered system; the number of tasks for interfering link-to-interfered link visibility calculation equals the number of interfering links multiplied by the number of interfered links; and the number of tasks for interfering index calculation equals the number of visible points at the receiver of the interfering link and the transmitter of the interfered link.

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