Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2018, Vol. 15, No. 6, pp. 48-59
Studying the stars of the celestial sphere section by two BOKZ-M60 star trackers
G.A. Avanesov
1 , N.I. Snetkova
1 , O.V. Filippova
1 , Ya.D. Elyashev
1 1 Space Research Institute RAS, Moscow, Russia
Accepted: 02.11.2018
DOI: 10.21046/2070-7401-2018-15-6-48-59
Two star trackers BOKZ-M60 made multiple measurements of the coordinates of the stars included in its onboard catalog on a small area of the celestial sphere with the size of 14° by declination and 21° by direct ascension. The values of random and systematic measurement errors were estimated based on the results obtained. It is shown that the causes of systematic errors are inextricably related to the background radiation in the nearest neighborhood of catalog stars. The contribution of systematic errors in the stars’ coordinates measurement to the error of the main point’s coordinates measurement is numerically estimated. Systematic errors in the measurement of stars’ coordinates, the groups of which are used by the star tracker at each given time, are converted into a measurement error of the main point’s coordinates, depending on the combination of stars in each group. It is possible to exclude systematic errors of stars’ coordinates measurement and, consequently, systematic errors in the calculation of the principal point’s coordinates by making corrections in the instrument’s onboard catalog, taking into account their parameters and individual characteristics of each catalog star’s neighborhood. The values of the necessary corrections can be measured by statistical processing of the results of numerous measurements of each star’s coordinates, or calculated, knowing the star tracker transfer function and using the astronomical catalog, describing in detail the nearest neighborhood of each catalog star.
Keywords: star tracker, astrometry, stars catalogue, systematic error, random error, background radiation, neighborhood of catalog stars
Full textReferences:
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