Method for acquiring high-energy electronic energy spectrum data of medium orbit satellite
Technical Field
The invention belongs to the field of high-energy electronic energy spectrum data of a medium orbit satellite, and particularly relates to a method for acquiring the high-energy electronic energy spectrum data of the medium orbit satellite.
Background
The medium orbit (MEO) is a satellite orbit with the height of about 20000 kilometers, and is the operation orbit of most global navigation satellites, the height of the medium orbit is just the height of the center of an earth external radiation zone, an equatorial region through which the medium orbit passes is just the center region of the external radiation zone, high-energy electrons can pass through a protective layer of the satellite and deposit on a medium inside the satellite, a deep charging effect can be caused, and the abnormal condition and even the fault condition of the satellite can be caused in the serious condition.
To estimate the severity of the deep charging effect of materials at different thicknesses, it is necessary to accurately know the worst high-energy electron environment, i.e., the worst high-energy electron spectrum, in the satellite orbit. However, not all the medium orbit satellites are equipped with high-energy electronic monitoring equipment, and therefore, the severe high-energy electronic environment of the medium orbit needs to be inverted through continuous monitoring data of related elements, so that timely grasping of the flux and energy spectrum of the high-energy electronic orbit of the medium orbit satellite is an important part for guaranteeing the safety of the satellite space environment, but most of the medium orbit satellites are not equipped with high-energy electronic detection equipment, and high-energy electronic detection data cannot be downloaded in real time, so that a satellite management mechanism cannot timely grasp the high-energy electronic environment of the satellite. Therefore, a method for acquiring the high-energy electronic energy spectrum data of the medium-orbit satellite is needed.
Disclosure of Invention
The invention aims to provide a method for acquiring high-energy electronic spectrum data of a medium orbit satellite.
The method comprises the following steps:
step 1: collecting high-energy electron 24-hour integral flux with energy more than 2MeV on a geosynchronous orbit;
step 2: calculating the maximum differential flux of the 1MeV high-energy electrons corresponding to 4 passes in 24 hours according to the integral flux;
and step 3: and calculating the energy spectrum of the high-energy electrons according to the maximum value of the maximum differential flux and calculating the logarithm relative error of the high-energy electrons.
Further, the differential flux of 1MeV high-energy electrons during the transit of the mid-orbit satellite through the core region of the outer radiating zone over the same 24 hour period can be expressed as:
fm1=1.7×106+3.75×106×(log10FG-6.845) (1)
wherein fm1 is the high-energy electron differential flux of the middle orbital 1MeV, and the unit is cm-2s-1sr-1MeV-1(ii) a FG is the fluence in cm of high-energy electrons with energies greater than 2MeV in the last 24 hours of geosynchronous orbit-2sr-1。
Further, the formula for the differential flux of high energy electrons of 1MeV can be expressed as:
fm(E)=10-1.11(E-1)+lg(fm1)
(2)
where fm (E) represents the high energy electron differential flux with energy E in cm-2s-1sr-1MeV-1(ii) a E represents the energy of the high-energy electron in MeV.
Further, the formula for calculating the logarithmic relative error of the high-energy electron flux of the middle orbit 1MeV is as follows:
in the formula f0To monitor the value, fcIs a calculated value. The calculated log relative error for the maximum high energy electron flux for orbital 1MeV during that day was 2.89%.
The invention has the following beneficial effects:
according to the invention, the high-energy electron flux and energy spectrum conditions of the core area of the external radiation zone penetrated by the medium orbit satellite can be calculated according to the high-energy electron flux data monitored by the stable geosynchronous orbit.
Drawings
FIG. 1 is a schematic flow diagram of the present invention;
Detailed Description
As shown in fig. 1, in this example, the present invention takes 30/4/2020 as an example, and calculates the maximum flux of 1MeV high-energy electrons of the medium-orbit satellite and the corresponding high-energy electron energy spectrum by using the daily integrated flux of high-energy electrons with energy greater than 2MeV measured by the GOES satellite, as a result of verifying that the detected data of the medium-orbit high-energy electrons is the GPS satellite with number 70.
In the present example, the present invention is 1.1X 10 in 2017, 4 months and 30 days (UT)9cm-2sr-1. Equation (1) is called, and FG is made 1.1 × 109Fm1 is obtained by9cm-2sr-1s-1MeV-1. Comparing with the data of satellite detection running on the middle orbit on the same day, the maximum flux on the same dayThe 1MeV high-energy electron differential flux of the region is 6.1X 106cm-2sr-1s-1MeV-1。
Step one, calculating the integrating flux of the geosynchronous orbit high-energy electrons in the last 24 hours, wherein the input data of the geosynchronous orbit high-energy electron flux can be obtained from a web site of the American space weather forecast center, and the integrating flux of the geosynchronous orbit high-energy electrons in the last 24 hours can be obtained.
And step two, substituting the integrated flux of which the energy is more than 2MeV in the last 24 hours of the geosynchronous orbit obtained in the step one into the formula (1), so as to obtain the maximum value of the 1MeV high-energy electronic differential flux in the process that the orbiting satellite passes through the core area of the outer radiation zone in the same time period.
Step three, changing Fm1 to 9.8 × 109Substituting equation (2) into E1.6 MeV, the differential flux of high-energy electrons with energy of 1.6MeV in the maximum flux region of the middle orbit is 2.14 × 109cm-2sr-1s-1MeV-1(ii) a When E is 2MeV, the differential flux of high-energy electrons having an energy of 2MeV in the maximum flux region of the middle orbit is 7.91 × 105cm-2sr-1s-1MeV-1. The high-energy electron differential flux of the orbit 1.6MeV in the day is 2.2 multiplied by 109cm-2sr-1s-1MeV-1(ii) a 2MeV high-energy electron differential flux of 4.5X 105cm-2sr-1s-1MeV-1. According to equation (3), the logarithmic relative errors are respectively: 0.19% and 4.31%.
The invention can evaluate the orbit high-energy electron energy spectrum in calculation according to the electron flux of 24 hours with the geosynchronous orbit energy being more than 2 MeV.
In order to test the feasibility of the provided calculation method, the maximum value of the high-energy electron differential flux of 1MeV, 1.6MeV and 2MeV of the medium orbit satellite P70 satellite at the independent (UT) of 2016 (8 months) to 10 months is selected for testing, and the input data is that the energy of the GOES satellite in the same time period is larger than the high-energy electron 24-hour integral flux of 2 MeV.
According to the calculation method given in "implementation procedure", the maximum values of the high-energy electron differential fluxes of the mid-orbit satellites 1MeV, 1.6MeV, and 2MeV of the above 41 time periods are calculated respectively and compared with the measured values of the mid-orbit satellites at the desired energy, and the results are shown in table 1.
The calculation results of the high-energy electron flux mode of the orbit in Table 1 are compared with the actual measurement results
In the evaluation of the high-energy particle flux model of the medium and high orbit satellite, the logarithmic flux relative error is generally adopted for evaluation, and the formula is as follows:
where err is the log flux relative error; lgf0(m) observations of differential flux at a certain energy of the medium orbit moat satellite, lgfc(m) is a differential flux calculation value of a corresponding time period, and m is a sample number.
By applying the method given in the formula (4), the present invention evaluates the calculation results of the middle orbits 1MeV, 1.6MeV and 2MeV provided in table 1 against the detection results of the corresponding energies of the middle orbits in the same period, and obtains relative errors of the differential fluxes of 1MeV, 1.6MeV and 2MeV of 5.13%, 6.28% and 7.28%, respectively.
The evaluation result shows that the method for deducing the high-energy electron energy spectrum of the medium-orbit high-energy electron E >1MeV based on the 24-hour integrated flux with the geosynchronous orbit energy larger than 2MeV is feasible.
Although the embodiments of the present invention have been described above, the above descriptions are only for the convenience of understanding the present invention, and are not intended to limit the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.