Research on space system realization condition indeterminations influence on performance factors dispersion

Аuthors

Lamzin V. V.

e-mail: 8916846583@mail.ru

Abstract

This article deals with questions of taking into account indeterminate and random factors during the space systems of Earth remote sensing design (SS ERS). In general there are indetermination of functional connection, project realization condition of SS ERS, demands to performance factor value targets indetermination). As it is shown fr om analyses an accounting of indeterminations and random factors as well as indetermination of working models and methods allows to attack a problem of estimation and selection of project decisions, take into account possible dispersion (loss) of quality. The methodology for influences investigation of realization condition indeterminations of perspective spacecraft (modification) as a part of SS ERS with indeterminations of engineering-and- economical models is proposed. During the methodology development the enlarged typical structure of SS ERS, which includes two main subsystems — space and terrestrial segments, was considered. It is assumed that existed facilities of terrestrial segments with known parameters are used and this article is devoted to parameters selection of perspective spacecraft as a part of SS ERS with modernization by given time period and risk estimation during system project realization.
There is optimization (estimation) problem statement of perspective spacecraft (modified spacecraft) as a part of SS ERS with modernization by given time period. The peculiarity of this problem statement is multicriteriality, it allows to estimate main performance indexes as functional system effectiveness, cost of project and labor intensity (framework) with taking into account indeterminate factors (connections). In parallel the possible risks (losses) during SS ERS project realization are estimated. Averaged risk should not exceed given lim it. In project models using for investigation of perspective space vehicles (modified spacecraft) there are outlined determinative parameters, which values depend on project realization time. As an example of these parameters there are coefficients of monetary and mass correspondences. As the coefficient of monetary and mass correspondences are defined based on experimental (statistical) data, then according to experimental data change (with taking into account scientific-and- technological advance) the coefficients change. Coefficients are random values and have dispersion.
Investigations of space system ERS realization condition indeterminations (project realization period duration, injection type, ratio between development cost and vehicle creation, quantity of spacecraft in system) influence on dispersion of summarized given cost during the system modernization within planned period are carried out. Method of statistical modeling is used during the estimation of engineering-and-economical characteristics of space system project with condition indeterminations of project realization. With the given quantity of statistical tests the rational (optimal) value of averaged costs (statistical expectation) and its dispersion (mean square deviation) are determinated. Investigations results are presented and analyzed. For example, analyses of mean square deviation value of presented summarized costs (project realization risk) shows, that increasing in amount of random values (coefficient of monetary and mass correspondences) and forecast interval leads to increasing in project realization risk.
Research results can be used not only during the perspective space vehicles development, but also during the development program correction of existed SS ERS as well as during the determination of demands to perspective space vehicles.

Keywords:

Earth remote sensing, modernization of space system, modified spacecraft, optical-electronic target equipment, realization condition indeterminations, engineering-and-economical model, random factors, performance factors

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