Method for Real-Time Calculation of Radiation Effects of Satellite On-Orbit Operating Environment

Abstract

The present invention provides a method for real-time calculating the radiation effect of a satellite in its on-orbit operating environment, belonging to the technical field of satellite space environment analysis. The method includes: S1. Import an orbit environment file into an environment solver to obtain corresponding parameters; S2. Select a time period N, a particle type, and a vehicle in the orbit environment file, set a minimum cumulative radiation simulation calculation time k, integrate the particle flux within the k time to generate an energy spectrum file, and the number of energy spectrum files is the ratio of N to k; S3. Set analysis parameters and the number of running particles, select a target structure, generate a corresponding script file according to the energy spectrum file, and input the script file into the solver for sequential solution; S4. Perform summation and normalization processing on the solution results to generate a final result. The present invention can real-time simulate and calculate the radiation damage degree of a spacecraft caused by different types of radiation particles during any period of operation in different orbit environments, and supports simultaneous calculation by multiple solvers, greatly improving the calculation efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of satellite space environment analysis, and particularly relates to a method for real-time calculating the radiation effect of the satellite in-orbit operating environment. Background Art

[0002] The space orbit determines the realization of satellite payload functions, detection geometric positions, life design baselines, launch vehicle costs, etc. At present, communication and navigation satellites, meteorological resource satellites, military reconnaissance satellites, etc. of various countries mainly operate in low Earth orbit (LEO), sun synchronous orbit (SSO), geosynchronous Earth orbit (GEO), and middle Earth orbit (MEO), and basically realize the serialized operation of satellites, supporting the application requirements of the national economy, people's livelihood, military strategy, etc. With the increasingly diverse application requirements in aspects such as satellite fixed-point observation, rapid revisit, satellite constellation communication, space attack and defense, and scientific exploration, satellite applications are developing towards multi-orbit networking systemization and reconnaissance countermeasure tacticalization, and countries are continuously strengthening the exploration and expansion of space orbit resources. Ultra-low orbits, elliptical orbits, medium orbits of 7000 - 8500 km, graveyard orbits, Lagrange point orbits, etc. have special position advantages and have gradually become the research focus.

[0003] During the in-orbit operation of the satellite, it will encounter the impact of various high-energy charged particles in space, which will cause radiation damage to the satellite surface materials, integrated circuit systems, temperature control surfaces, etc., leading to satellite performance degradation and functional failures, and further affecting the completion of satellite missions. In 2001, the American Aerospace Corporation counted the on-orbit failure causes of 298 satellites caused by space environment effects (as shown in Figure 1 ), among which satellite failures caused by the total dose, single event effect, charging and discharging effect, etc. brought by the special space environment have exceeded 75% of the total number of environment-induced failures. In order to reduce the incidence of on-orbit satellite failures, it is crucial to simulate and analyze the radiation resistance of satellites during the satellite R & D process and guide the improvement of satellite structures according to the calculation results. After decades of development, with the continuous in-depth understanding of space environment effects by humans, relatively mature ground simulation test methods for space environments have gradually formed. However, the existing methods for simulating in-orbit environments and calculating various radiation effects have low accuracy and efficiency. Summary of the Invention

[0004] In view of the above problems in the prior art, the present invention provides a method for real-time calculating the radiation effect of the satellite in-orbit operating environment.

[0005] To achieve the above object, the present invention is specifically realized through the following technologies:

[0006] The present invention provides a method for real-time calculating the radiation effect of a satellite in orbit, including the following steps:

[0007] S1. Import an orbit environment file into an environment solver to obtain corresponding parameters;

[0008] S2. Select a certain time period N in the orbit environment file, select a particle type and a spacecraft according to the orbit environment file, set the minimum cumulative radiation simulation calculation time k, and use the first formula to integrate the particle flux within the minimum cumulative radiation simulation calculation time k to generate an energy spectrum file that can be used for solver calculation, and the number of the energy spectrum files is the ratio of N to k;

[0009] The first formula includes:

[0010] where t m is the termination time of the minimum cumulative radiation simulation calculation, t m-1 is the start time of the minimum cumulative radiation simulation calculation, m is an integer greater than 1, is the particle flux per second within the minimum cumulative radiation simulation calculation time k, with the unit / cm 2 ·s, and Φ(t) is the total particle fluence within the minimum cumulative radiation simulation calculation time k, with the unit / cm 2 ;

[0011] S3. Set analysis parameters and the number of running particles, select a target structure, generate a corresponding script file according to the energy spectrum file in step S2, and input the script file into the solver for sequential solution;

[0012] where the solver is a solution operation program written in C language using Geant4 software based on the Monte Carlo method, the number of running particles is the number of incident particles for simulated irradiation, and the target structure is the sensitive body to be calculated;

[0013] S4. Sum and normalize the solution results in step S3 to generate a final result.

[0014] Further, in step S1, the orbit environment file is an AP-8 radiation belt proton environment file or an AE-8 radiation belt electron environment file.

[0015] Further, the proton energy range in the AP-8 radiation belt proton environment file is 0.1 MeV - 400 MeV, and the electron energy range in the AE-8 radiation belt electron environment file is 40 keV - 7 MeV.

[0016] Further, in step S1, the corresponding parameters include one or more of the orbital operation time, the particle type, the particle energy, the particle flux, and the aircraft.

[0017] Further, the particle type includes at least one of protons, electrons, and heavy ions.

[0018] Further, in step S3, the analysis parameters include one or more of the total ionization dose, non-ionizing deposition, non-ionizing energy loss, linear energy transfer, and cumulative flux.

[0019] Further, in step S3, the range of the number of running particles is from 1 to the total particle fluence within the minimum cumulative radiation simulation calculation time k.

[0020] Further, after step S4, the following steps are further included:

[0021] S5. Perform visual analysis.

[0022] Further, the visual analysis is as follows: taking the time point as the abscissa, the difference between two adjacent time points is the minimum cumulative radiation simulation calculation time k, taking the analysis parameter as the ordinate, and performing visual output in the form of a chart.

[0023] The present invention uses the above formula to convert the real aircraft on-orbit operation environment file into the energy spectrum file used by the software for calculation, and then performs the final calculation through the Monte Carlo method, which can simulate and calculate in real time the radiation damage degree of different types of radiation particles on a spacecraft during any period of operation in different orbital environments. During the conversion process from the orbital environment file to the energy spectrum file, it involves dividing the calculation time period, and the smaller the divided time period, the higher the calculation accuracy. And the present invention supports simultaneous calculation by multiple solvers, which greatly improves the calculation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 Distribution statistics of the reasons for satellite on-orbit anomalies caused by space environment effects;

[0026] Figure 2 Relationship diagram between time period N and minimum cumulative radiation simulation calculation time k;

[0027] Figure 3 Particle track display diagram of Embodiment 1 of the present invention;

[0028] Figure 4 This is the result file table of Embodiment 1 of the present invention; in the figure, a): LET, b): TID, c): NIEL, d): FLUENCE;

[0029] Figure 5 This is the bar chart of the result file of Embodiment 1 of the present invention; in the figure, a): LET, b): TID, c): FLUENCE, d): NIEL. Detailed implementation manners

[0030] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other. In addition, the meanings of the terms "include", "contain", and "have" are non-restrictive, that is, other steps and other components that do not affect the results can be added. Unless otherwise specified, the materials, equipment, and reagents are all commercially available.

[0031] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention will be given in conjunction with the accompanying drawings.

[0032] When satellites and other aircraft are in orbit, the key parts are mainly affected by the comprehensive space radiation environment factors such as protons (AP-8), electrons (AE-8), and heavy ions with different energies in the on-orbit environment. The present invention converts the known orbit environment file into the input energy spectrum file of the existing solver, and based on the integral energy spectrum or differential energy spectrum derived from the on-orbit environment energy spectrum, uses the Geant4 software and adopts the Monte Carlo method for calculation, and can accurately simulate the radiation damage degree of the orbit environment particles on the on-orbit satellites during any on-orbit operation time period. It has important engineering value and scientific significance for predicting and preventing the in-orbit flight failure of aircraft and revealing the relationship between the performance degradation of aircraft materials and devices and the radiation damage effects of various on-orbit environment particles.

[0033] The application objects of the method of the present invention include materials, devices, electronic systems, and structures.

[0034] The embodiment of the present invention provides a method for real-time calculating the radiation effect of the satellite on-orbit operation environment, including the following steps:

[0035] S1. Import the orbit environment file into the environment solver to obtain the corresponding parameters;

[0036] The environmental solver is a program written in C language and QT. The above-mentioned orbital environmental file is an AP-8 radiation belt proton environmental file or an AE-8 radiation belt electron environmental file. The AP-8 model is the eighth version of the model established by J.I. Vette et al. of NASA's Goddand Space Flight Center for radiation belt protons. This model can cover the proton region of the Earth's radiation belt more fully, and the proton energy range involved is 0.1 MeV - 400 MeV, becoming an internationally widely used Earth radiation belt proton environmental model. The AE-8 model is the most widely used Earth radiation belt electron model so far, which can give the integral flux and differential flux distributions of radiation belt electrons under different energy (E) and geomagnetic coordinate (B, L) conditions respectively. The covered spatial region reaches the range of (L = 1.2 - 11RE), and has a relatively wide energy interval (40 keV - 7 MeV), becoming the model with the widest coverage of Earth radiation belt electrons in space and energy so far.

[0037] The corresponding parameters mentioned above include one or more of the orbital operation time, particle type, particle energy, particle flux φ(t), and the aircraft. The particle type includes at least one of protons (AP-8), electrons (AE-8), and heavy ions, and the heavy ion is any ion in the periodic table. After selecting the particle type, the particle energy and flux are determined.

[0038] S2. Select a certain time period of N hours in the orbital environmental file, and select the particle type and the aircraft according to the orbital environmental file, set the minimum cumulative radiation simulation calculation time of k seconds, and use the first formula to calculate the particle flux within the minimum cumulative radiation simulation calculation time of k seconds for integration to generate an energy spectrum file that can be used for solver calculation;

[0039] The first formula includes:

[0040]

[0041] where t m is the termination time of the minimum cumulative radiation simulation calculation, t m-1 is the start time of the minimum cumulative radiation simulation calculation, m is an integer greater than 1, is the particle flux per second within the minimum cumulative radiation simulation calculation time of k seconds, with the unit / cm 2 ·s, Φ(t) is the total particle fluence within the minimum cumulative radiation simulation calculation time of k seconds, with the unit / cm 2 ;

[0042] See Figure 2 , the time period N, the minimum cumulative radiation simulation calculation time k, and the start and end times t m-1 and t mThe relationship is:

[0043]

[0044] Thus, the number of energy spectrum files generated is the ratio of N to k. For example, assuming that m is 3 and N is 3k (i.e., t3-t0), the first energy spectrum file is generated by integrating during the time t1-t0 (k seconds), the second energy spectrum file is generated by integrating during the time t2-t1 (k seconds), and the third energy spectrum file is generated by integrating during the time t3-t2 (k seconds).

[0045] In step S2, the particle type is determined according to the type of the orbital environment file. For example, when the AP-8 radiation belt proton environment file is imported, the particle type is selected as proton. The same orbital file can contain multiple aircraft, but only one aircraft can be calculated during calculation, so the corresponding aircraft must be selected.

[0046] S3, setting analysis parameters, running particle number, selecting target structure, generating corresponding script file according to the energy spectrum file in step S2, and inputting the script file into the solver for solving in sequence;

[0047] The solver is a solution operation program written in C language using Geant4 software based on the Monte Carlo method. The above-mentioned analysis parameters include but are not limited to: Total Ionizing Dose (TID), Non-Ionizing Deposition (NID), Non-Ionization Energy Loss (NIEL), Linear Energy Transfer (LET) and Integrated Flux (FLUENCE). The number of running particles is the number of incident particles for simulated irradiation, and the optional range is 1 to the total particle injection within the minimum cumulative radiation simulation calculation time k seconds; illustratively, the number of running particles is 100,000. The target structure is the sensitive body that needs to be calculated.

[0048] S4. Sum and normalize the solution results of step S3 to generate a final result.

[0049] Specifically, each energy spectrum file generates a script file, and each script file corresponds to the aforementioned minimum cumulative radiation simulation calculation time k seconds (t m -t m-1) If the results are generated from the energy spectrum file, and the analysis parameters are set to select TID, NID, NIEL, LET, and FLUENCE, then each script will generate a set of TID, NID, NIEL, LET, and FLUENCE data, which is calculated by the Monte Carlo method. The foregoing set of data is summed and normalized to generate the final result.

[0050] The present invention uses the above formula to convert the real aircraft on-orbit operating environment file into an energy spectrum file used by the software for calculation, and then calculates the final result based on the Monte Carlo method and using Geant4 software. It can simulate and calculate in real time the radiation damage degree of different types of radiation particles on a spacecraft during any period of operation in different orbital environments. During the conversion of the orbital environment file to the energy spectrum file, it involves dividing the calculation time period, and the smaller the divided time period, the higher the calculation accuracy. Moreover, the present invention supports simultaneous calculation by multiple solvers, which greatly improves the calculation efficiency.

[0051] For intuitive observation, preferably, after step S4, there is also step S5:

[0052] S5. Conduct visual analysis.

[0053] Specifically, the present invention uses the time point as the abscissa, the difference between two adjacent time points as the minimum cumulative radiation simulation calculation time k seconds, and uses analysis parameters such as TID, NIEL, LET, and FLUENCE as the ordinates, and outputs them visually in the form of a table and a bar chart, so that the results can be read intuitively.

[0054] The following further elaborates the present invention in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. The experimental methods without specific conditions noted in the following embodiments are usually in accordance with the conditions recommended by the manufacturer.

[0055] Embodiment 1

[0056] A method for real-time calculating the radiation effect of a satellite in orbit, including the following steps:

[0057] S1. Import the orbital environment file into the environment solver. The orbital environment file is an AE-8 radiation belt electron environment file, and parameters including orbital operation time, particle type, particle energy, particle flux φ(t), and aircraft name are obtained;

[0058] S2. Select any time period of N hours in the orbital environment file (from 13:00:00 on January 1, 2017 to 19:00:00 on January 4, 2017 in this embodiment), select the particle type (electrons in this embodiment) and the aircraft according to the orbital environment file, set the minimum cumulative radiation simulation calculation time of k seconds (the minimum cumulative radiation simulation calculation time is 6 hours, i.e., 21,600 seconds in this embodiment), and use the first formula to calculate the particle flux within the minimum cumulative radiation simulation calculation time of k seconds Integrate to generate an energy spectrum file that can be used for solver calculation;

[0059] S3. Set the analysis parameters (TID, NIEL, LET, and FLUENCE in this embodiment), the number of running particles (100,000 in this embodiment), select the target structure, generate the corresponding script file according to the energy spectrum file in step S2, and input the script file into the solver for sequential solution;

[0060] S4. Sum and normalize the solution results of step S3 (normalize to the result caused by one particle) to generate the final result;

[0061] S5. Use the time point as the abscissa, the difference between two adjacent time points as the minimum cumulative radiation simulation calculation time of k seconds, use the analysis parameters such as TID, NIEL, LET, and FLUENCE as the ordinate, and perform visual output in the form of a table and a bar chart.

[0062] In this embodiment, the radiation source is set to include an aluminum shell sphere with isotropic incident directions. Figure 3 It is a display diagram of the electron radiation particle track of the outermost aluminum shell of this structure. The light gray lines in the figure represent the electron paths, and the dark gray lines represent the γ-rays excited by the electron irradiation of the aluminum shell. Calculate TID, NIEL, LET, and FLUENCE for this geometric shell structure.

[0063] Figure 4 、 5 It is a table form and a bar chart of the above calculation results, which well reflects the radiation damage status of a certain structure of the aircraft at each time period during on-orbit operation.

Claims

1. A method for real-time calculating the radiation effect of the satellite's on-orbit operating environment, characterized in that It includes the following steps: S1. Import the orbital environment file into the environment solver to obtain corresponding parameters; S2. Select a certain time period N in the orbital environment file, select the particle type and the aircraft according to the orbital environment file, set the minimum cumulative radiation simulation calculation time k, and use the first formula to calculate the particle flux within the minimum cumulative radiation simulation calculation time k Integrate to generate an energy spectrum file that can be used for solver calculation. The number of the energy spectrum files is the ratio of N to k; The first formula includes: where t m is the termination time of the minimum cumulative radiation simulation calculation, t m-1 is the start time of the minimum cumulative radiation simulation calculation, m is an integer greater than 1, is the particle flux per second within the minimum cumulative radiation simulation calculation time, and Φ(t) is the total particle fluence within the minimum cumulative radiation simulation calculation time; S3. Set the analysis parameters and the number of running particles, select the target structure, generate a corresponding script file according to the energy spectrum file described in step S2, and input the script file into the solver for sequential solution; Among them, the solver is a solution operation program written in C language using Geant4 software based on the Monte Carlo method, the number of running particles is the number of incident particles for simulated irradiation, and the target structure is the sensitive body to be calculated; S4. Sum and normalize the solution results of step S3 to generate the final result.

2. The method according to claim 1, characterized in that, In step S1, the orbital environment file is an AP-8 radiation belt proton environment file or an AE-8 radiation belt electron environment file.

3. The method according to claim 2, wherein In the AP-8 radiation belt proton environment file, the proton energy range is 0.1 MeV - 400 MeV, and in the AE-8 radiation belt electron environment file, the electron energy range is 40 keV - 7 MeV.

4. The method according to claim 1, wherein In step S1, the corresponding parameters include one or more of the orbital running time, the particle type, the particle energy, the particle flux, and the aircraft.

5. The method according to claim 4, characterized in that, The particle type includes at least one of protons, electrons, and heavy ions.

6. The method according to any one of claims 1-5, characterized in that, In step S3, the analysis parameters include one or more of the total ionization dose, non-ionizing deposition, non-ionizing energy loss, linear energy transfer, and cumulative flux.

7. The method according to any one of claims 1-5, characterized in that, In step S3, the range of the number of running particles is from 1 to the total particle fluence within the minimum cumulative radiation simulation calculation time k.

8. The method according to claim 1, characterized in that, After step S4, the following steps are further included: S5. Conduct visual analysis.

9. The method according to claim 8, wherein The visual analysis is as follows: taking the time point as the abscissa, the difference between two adjacent time points as the minimum cumulative radiation simulation calculation time k, taking the analysis parameter as the ordinate, and performing visual output in the form of a chart.

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