CN104765964A - Space environment sensitive parameter screening method - Google Patents

Abstract

The invention provides a space environment sensitive parameter screening method. According to the method, telemetry parameters are screened through mechanism analysis and correlation calculation, and parameters related to the space environment and capable of directly reflecting the actual influences of the space environment on an on-orbit spacecraft can be obtained, that is, the space environment sensitive parameters are screened; then, the space environment sensitive parameters of the on-orbit spacecraft are monitored and analyzed by means of the prior art, and spacecraft on-obit management personnel can monitor the actual influences on the spacecraft of the space environment and conduct related operation according to the influences, so that the on-orbit safe and reliable operation of the spacecraft is guaranteed, and it is guaranteed that space missions are accomplished completely.

Description

A kind of space environment sensitive parameter screening technique

Technical field

The invention belongs to spacecraft in-orbit management field, particularly relate to a kind of space environment sensitive parameter screening technique.

Background technology

The impact of space environment on spacecraft in-orbit has become the spacecraft key factor considered of managerial demand in-orbit.While long-life satellite is growing, advanced composite material (ACM) and microelectronic component are also applied more and more, and the possibility of space environment induced malfunction is increased.

Spacecraft has nearly several thousand telemetry parameters, and some of them telemetry parameter can be more responsive to the change of space environment, and when namely space environment has had a larger change, remote measurement value can change.Wherein some remote measurement change directly reflects exception or the fault of spacecraft.The change of these remote measurement values can reflect the impact of space environment on spacecraft intuitively, is referred to as space environment sensitive parameter.By understanding to the analysis of these telemetry parameters the actual influence that space environment brings spacecraft in-orbit.But due to telemetry parameter nearly several thousand, prior art not yet has means to detect all telemetry parameters.

Summary of the invention

For solving the problem, the invention provides a kind of space environment sensitive parameter screening technique.Analyze by mechanism and correlativity the susceptibility that spacecraft telemetry parameter changes for space environment, the size according to the related coefficient calculated carries out the screening of space environment sensitive parameter.

Space environment sensitive parameter screening technique of the present invention, is characterized in that, comprise the following steps:

Step 1, Analysis on Mechanism filters out object to be screened, and object to be screened belongs to the spacecraft telemetry arranged specially for Single event upset effecf, comprising: single-particle inversion counts, and single-bit error counts, and double-bit errors counts;

Step 2, screens spacecraft telemetry, obtains space environment sensitive parameter;

Step 21, carries out pre-service to spacecraft telemetry;

The first step: reject the outlier exceeding spacecraft telemetry range;

Second step: spacecraft telemetry divides GEO track and IGSO track telemetry parameter, other track telemetry parameter two class according to the difference of affiliated spacecraft orbit; The telemetry parameter of other track is divided three classes according to the difference of telemetry parameter range again: the first kind is the variable of range maximal value <=15; Equations of The Second Kind is the variable of range maximal value >15 and <=256; 3rd class is the variable of range maximal value >256;

3rd step: for the telemetry parameter of GEO track and IGSO track, if continuous two data jumps are cumulative more than 3, then thinks that two data are all outlier and reject; For the telemetry of the three types of other track, the variable of the first type, the change of all generations is all true value; The variable of the second type, if continuous two data jumps are cumulative more than 10, then thinks that rear data are outlier and reject; The variable of the third type, if continuous two data jumps are cumulative more than 1000, then thinks that rear data are outlier and reject;

Step 22, by Pearson correlation coefficients, Calculation of correlation factor is carried out to pretreated spacecraft telemetry and space environment parameter, absolute value according to related coefficient carries out sorting and gets the parameter of the forward setting quantity of correlativity, or by defining correlation coefficient threshold and getting the parameter being greater than this threshold value, as the space environment sensitive parameter set filtered out.

Further, represent related coefficient in described step 22 with r, and the absolute value of r shows that more greatly correlativity is stronger, computing formula is as follows:

$r=\frac{1}{n-1}\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\left(\frac{X_i-\stackrel{\&OverBar;}{X}}{S_X}\right)\left(\frac{Y_i-\stackrel{\&OverBar;}{Y}}{S_Y}\right)$

Wherein, X _i, Y _ifor Two Variables, X _ifor needing the spacecraft telemetry in i-th moment of screening, Y _ibe the Space environment monitor data in i-th moment; for the average of Two Variables in n moment; S _x, S _yfor the sample variance of Two Variables in n moment.

Further, in described step 22, correlation coefficient threshold is 0.2.

Beneficial effect: utilize Analysis on Mechanism and correlation calculations to screen telemetry parameter, can obtain relevant to space environment and directly can reflect the parameter of space environment to the actual influence of spacecraft in-orbit, namely the screening of space environment sensitive parameter is achieved, recycling prior art monitors spacecraft space environment sensitive parameter in-orbit and analyzes, spacecraft in-orbit managerial personnel can monitor space environment on the actual influence of spacecraft and according to the size affected, carry out associative operation, thus ensure spacecraft safe and reliable operation in-orbit, guarantee satisfactorily completing of space mission.

Accompanying drawing explanation

Fig. 1 is space environment sensitive parameter screening technique process flow diagram of the present invention.

Fig. 2 is the result schematic diagram utilizing the present invention to obtain the correlativity of the 30 satellite single-bit error counting and logEeV0.6M.

Embodiment

As shown in Figure 1, space environment sensitive parameter screening technique of the present invention comprises the following steps:

Step 1, Analysis on Mechanism filters out object to be screened, and object to be screened belongs to the spacecraft telemetry arranged specially for Single event upset effecf, comprising: single-particle inversion counts, single-bit error, double-bit errors;

For space environment aspect, the sun is the principal element affecting geospace environment, and solar activity is very complicated and changeable, but is wherein also no lack of regularity, as the time-interval averaging between the solar activity peak year is about 11 years.Space environment refers to the distribution of sun surface in instantaneous or short time, solar wind, magnetosphere, the state of ionosphere and thermosphere and space junk, micrometeor.Severe space environment can cause the collapse of satellite transit, communication, navigation, causes accidental damage to spacecraft.Space environment is mainly the factor that spacecraft affects: atmospheric disturbance, gravitational field change, disturbance of magnetic field, radiation damage, elemental oxygen damage, surperficial discharge and recharge, interior electric discharge, single particle effect etc.Wherein atmospheric disturbance, the change of gravitational field change major effect satellite orbit, be difficult to reflect from telemetry parameter; Radiation damage, elemental oxygen damage are mainly for the impact of material, and being a gradual process, having considered that it affect when designing, it is not very large for affecting spacecraft; Disturbance of magnetic field is comparatively large on the spacecraft impact being provided with magnetic-field-sensitive device and magnetic distance power device, affects less on the spacecraft impact of not installing magnetic-field-sensitive device and magnetic distance power device.

According to the theoretical analysis of space environment on spacecraft impact in-orbit, single particle effect and this three classes environmental factor of inside and outside charging and discharging effects are on spacecraft impact is larger in-orbit.These effects are larger on the equipment impact containing large scale integrated circuit devices such as () RAM, FPGA, DSP, CPU such as central computer, Star Service, number pipe computing machines.Electron device with comparer, CMOS tube can receive the disturbing effects such as single-particle.Space environment also can have impact to cause abnormal saltus step on partial switch state.Such as single-particle inversion counting, single-bit error, the spacecraft telemetries such as double-bit errors are exactly for Single event upset effecf, the special telemetry parameter arranged.The telemetry parameter change that the space environment remote measurement sensitive parameter of the application mainly causes for these three kinds of factors is chosen.

Step 2, is screened by data statistics result in-orbit spacecraft telemetry, obtains space environment sensitive parameter.

The impact of space environment on spacecraft is in-orbit a probability event, except the change of space environment parameter, also relevant with the duty of spacecraft with the measure of spacecraft equipment model, layout, protection.The situation of change of telemetry parameter under once or twice space environment event is nonsensical, so want collection spacecraft telemetry parameter data as much as possible to add up, screens according to statistics.

The principle of space environment sensitive parameter screening is screened according to the correlativity size between spacecraft space sensitive parameter and space environment.Screening technique flow process as shown in Figure 1.

Step 21, carries out pre-service to spacecraft telemetry.

Because spacecraft telemetry can generate some outlier in transmission and process, these outlier can bring deviation to the selection result, so need the spacecraft telemetry of screening to carry out pre-service.Pre-service mainly comprises four steps:

The first step: reject the outlier exceeding spacecraft telemetry range.

Second step: spacecraft telemetry divides GEO track and IGSO track, other track telemetry parameter two class according to the difference of affiliated spacecraft orbit.Telemetry parameter, again according to the difference of telemetry parameter range, is classified, is mainly divided into three classes: the first kind is the variable of range maximal value <=15 by the telemetry parameter of other track; Equations of The Second Kind is the variable of range maximal value >15 and <=256; 3rd class is the variable of range maximal value >256.

3rd step: if think outlier for the telemetry parameter variable quantity of GEO track and IGSO track more than 3 and reject.For the telemetry of the three types of other track, adopt different statistics strategies take remote measurement respectively parameter transition times statistics.For the variable of the first type, the change of all generations is all true value; For the variable of the second type, if continuous two data jumps are cumulative more than 10, then think that a rear numerical value is outlier and rejects; For the variable of the third type, if continuous two data jumps are cumulative more than 1000, then think that a rear numerical value is outlier and rejects.

According to the telemetry parameter transition times of continuous print time series (in units of sky) statistics every day.Space environment parameter is also that unit adds up according to sky.

Step 22, Calculation of correlation factor is carried out to spacecraft telemetry and space environment parameter (reflecting the Monitoring Data of space environment), absolute value according to related coefficient carries out sorting and gets some forward parameter of correlativity, or by definition correlation coefficient threshold, be greater than some parameter of this threshold value as the set of space environment sensitive parameter.

Correlation analysis be multivariate statistical analysis an important subject it be a kind of statistical analysis technique relevant between research two groups of variablees, effectively can disclose the mutual linear dependence between two groups of variablees.Canonical correlation analysis can weigh the correlation degree between variable by the related coefficient calculating variable.Its ultimate principle is: hold the correlationship between two groups of indexs on the whole, in two groups of variablees, extract representational two generalized variable U and V (being respectively the linear combination of each variable in Two Variables group) respectively, utilize the correlationship between these two generalized variables to reflect overall relevancy between two groups of indexs.The correlationship of two stochastic variables can be weighed with their simple correlation coefficient.

Calculate its correlativity by Pearson correlation coefficients, Pearson correlation coefficients (Pearson correlationcoefficient) is a kind of linearly dependent coefficient.Pearson correlation coefficients is used to the statistic reflecting Two Variables linear correlation degree.Related coefficient r represents, what r was that related coefficient describes is that Two Variables linearly is correlated with strong and weak degree.The absolute value of r shows that more greatly correlativity is stronger.Computing formula is as follows:

$r=\frac{1}{n-1}\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\left(\frac{X_i-\stackrel{\&OverBar;}{X}}{S_X}\right)\left(\frac{Y_i-\stackrel{\&OverBar;}{Y}}{S_Y}\right)$

Wherein n is sample size; X _i, Y _ifor Two Variables; X _ifor needing the telemetry parameter of screening, each spacecraft has multiple needs to screen telemetry parameter, and each telemetry parameter carries out calculating sifting respectively; Y _ifor Space environment monitor data, Space environment monitor parameter also has multiple, multiple Space environment monitor parameter and each telemetry parameter needing to screen calculating sifting respectively in screening; for the average of Two Variables; S _x, S _yfor the sample variance of Two Variables.

Because Pearson correlation coefficients is the correlativity linearly reflecting Two Variables, do not require that these two data have data area and the time point of equity completely, be applicable to the screening of space environment sensitive parameter.

By calculating the related coefficient between telemetry parameter and space environment parameter, absolute value according to related coefficient sorts, and then by defining correlation coefficient threshold or getting some forward parameter of correlativity, as the set of space environment sensitive parameter, feature and the analysis of relative coefficient result of calculation of spacecraft is affected according to space environment, think Pearson correlation coefficients >0.2 time, telemetry parameter just can think relevant to space environment, can screen as space sensitive parameter.

Embodiment

First according to Analysis on Mechanism, to 78 in-orbit spacecraft more than 10 ten thousand telemetry parameters screen, filter out the telemetry parameter that 569 of 61 spacecrafts are in-orbit relevant to space environment.

Again according to above-mentioned method and technology flow process, first pre-service is carried out to telemetry parameter data, deleting unrelidble data, remote measurement transition times was added up according to day, carry out Calculation of correlation factor with each chronometer data day by day, telemetry parameter related coefficient being greater than 0.2 screens as space environment sensitive parameter.

569 telemetries of 2007 to 2013 61 spacecrafts are in-orbit screened, carries out correlation computations with 52 kinds of space environment parameters (see table 2).Filter out 53 space environment sensitive parameters.(see table 3)

Wherein with the telemetry parameter single-bit of the 30 satellite (XX-30 star) mistake counting and the data of logEeV0.6M as shown in Figure 2, its correlativity is 0.34.

Table 2 space environment parameter (chronometer data)

The space environment sensitive parameter that table 3 filters out

Certainly; the present invention also can have other various embodiments; when not deviating from the present invention's spirit and essence thereof; those of ordinary skill in the art are when making various corresponding change and distortion according to the present invention, but these change accordingly and are out of shape the protection domain that all should belong to the claim appended by the present invention.

Claims (3)

1. a space environment sensitive parameter screening technique, is characterized in that, comprises the following steps:

Step 1, Analysis on Mechanism filters out object to be screened, and object to be screened belongs to the spacecraft telemetry arranged specially for Single event upset effecf, comprising: single-particle inversion counts, and single-bit error counts, and double-bit errors counts;

Step 2, screens spacecraft telemetry, obtains space environment sensitive parameter;

Step 21, carries out pre-service to spacecraft telemetry;

The first step: reject the outlier exceeding spacecraft telemetry range;

Second step: spacecraft telemetry divides GEO track and IGSO track telemetry parameter, other track telemetry parameter two class according to the difference of affiliated spacecraft orbit; The telemetry parameter of other track is divided three classes according to the difference of telemetry parameter range again: the first kind is the variable of range maximal value <=15; Equations of The Second Kind is the variable of range maximal value >15 and <=256; 3rd class is the variable of range maximal value >256;

3rd step: for the telemetry parameter of GEO track and IGSO track, if continuous two data jumps are cumulative more than 3, then thinks that two data are all outlier and reject; For the telemetry of the three types of other track, the variable of the first type, the change of all generations is all true value; The variable of the second type, if continuous two data jumps are cumulative more than 10, then thinks that rear data are outlier and reject; The variable of the third type, if continuous two data jumps are cumulative more than 1000, then thinks that rear data are outlier and reject;

Step 22, by Pearson correlation coefficients, Calculation of correlation factor is carried out to pretreated spacecraft telemetry and space environment parameter, absolute value according to related coefficient carries out sorting and gets the parameter of the forward setting quantity of correlativity, or by defining correlation coefficient threshold and getting the parameter being greater than this threshold value, as the space environment sensitive parameter set filtered out.

2. space environment sensitive parameter screening technique as claimed in claim 1, it is characterized in that, represent related coefficient in described step 22 with r, and the absolute value of r shows that more greatly correlativity is stronger, computing formula is as follows:

$r=\frac{1}{n-1}\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\left(\frac{X_i-\stackrel{\&OverBar;}{X}}{S_X}\right)\left(\frac{Y_i-\stackrel{\&OverBar;}{Y}}{S_Y}\right)$

Wherein, X _i, Y _ifor Two Variables, X _ifor needing the spacecraft telemetry in i-th moment of screening, Y _ibe the Space environment monitor data in i-th moment; for the average of Two Variables in n moment; S _x, S _yfor the sample variance of Two Variables in n moment.

3. space environment sensitive parameter screening technique as claimed in claim 1, it is characterized in that, in described step 22, correlation coefficient threshold is 0.2.