Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2020, Vol. 17, No. 1, pp. 68-79
Research and compensation for the methodological error in measuring the coordinates of stars by orientation sensors during flight operation
G.A. Avanesov
1 , R.V. Bessonov
1 , E.V. Belinskaya
1 , N.N. Brysin
1 , S.V. Voronkov
1 , A.N. Kurkina
1 , P.S. Smetanin
1 1 Space Research Institute RAS, Moscow, Russia
Accepted: 24.01.2020
DOI: 10.21046/2070-7401-2020-17-1-68-79
The paper presents the results of a study of one of the components of the error in measuring the coordinates of the energy centers of stars recorded on CCD-matrices of orientation sensors. The main material for research was accumulated during the operation of stellar sensors of the BOKZ family on board spacecraft in near-Earth orbit. A systematic dependence of the error of determining the location of the star on the fractional part of the coordinates of the star in the image is obtained, which obeys the harmonic law and is called the methodological error. This type of error is due to the calculation of the energy center of the object using the weighted average method, as well as the heterogeneity of the structure of the elements of the CCD-matrix. Two methods for its determination are proposed: one of them is based on long-term observation of the error in measuring the location of a single star, and the other on the estimation of the distribution of the coordinates of stars over the pixel field. The possibility of effective compensation of a methodological error by the example of several stellar sensors of the BOKZ family is demonstrated. One of the causes of the methodological error related to the heterogeneity of the cells of the CCD-matrices that are used in the devices of the BOKZ family is considered in detail. An assessment of the non-uniformity of the sensitivity of the element of the CCD-matrix, based on observations of changes in the integral brightness of stars as they move through the image, confirms the heterogeneity of the cell structure along one of the axes.
Keywords: star tracker, astrometry, orientation errors, methodical error, CCD, uneven pixel sensitivity
Full textReferences:
- Avanesov G. A., Kondrat’eva T. V., Nikitin A. V., Issledovanie smeshcheniya energeticheskogo tsentra izobrazhenii zvezd otnositel’no geometricheskogo tsentra na PZS-matritse i korrektsiya metodicheskoi oshibki (The study of the displacement of the energy center of the images of stars relative to the geometric center on the CCD-matrix and the correction of the methodological error), Vserossiiskaya nauchno-tekhnicheskaya konferentsiya “Sovremennye problemy opredeleniya orientatsii i navigatsii kosmicheskikh apparatov” (All-Russia Scientific and Technical Conf. “Modern Problems of Determining the Orientation and Navigation of Spacecraft”), Proc., Tarusa, 22–25 Sept. 2008, Moscow: IKI RAS, 2009, pp. 421–446.
- Avanesov G. A., Bessonov R. V., Kurkina A. N., Smetanin P. S., Tekhnologiya nazemnoi obrabotki dannykh o koordinatakh zvezd v tselyakh povysheniya tochnosti geoprivyazki snimkov Zemli iz kosmosa (Technology for ground processing of data on the stars’ coordinates in order to improve the accuracy of georeferencing Earth images from space), Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2018, Vol. 15, No. 6, pp. 31–38, DOI: 10.21046/2070-7401-2018-15-6-31-38.
- Belichenko M. L., Bessonov R. V., Zavgorodnii D. S., Elyashev Ya. D., Prokhorova S. A., Klassifikatsiya i analiz pogreshnosti izmereniya koordinat obʺektov na kadrakh zvezdnogo neba (Classification and analysis of errors in estimating coordinates of objects in images of starry sky), Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2017, Vol. 14, No. 3, pp. 67–77, DOI: 10.21046/2070-7401-14-3-67-77.
- Bessonov R. V., Belinskaya E. V., Brysin N. N., Voronkov S. V., Prokhorova S. A., Stroilov N. A., Forsh A. A., Stendovoe issledovanie pogreshnosti opredeleniya energeticheskogo tsentra yarkosti izobrazheniya zvezd v zvezdnykh datchikakh (The test bench study of star image energy center determination error in star trackers), Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2018, Vol. 15, No. 6, pp. 82–89, DOI: 10.21046/2070-7401-2018-15-6-82-89.
- Nemaltsyna V. A., Shchekin A. M., Obʺektivnyi metod kontrolya formy izobrazheniya pri vzaimnoi vystavke svetosil’nogo obʺektiva so srednim uglovym polem i matrichnogo priemnika izlucheniya na primere zvezdnogo pribora tochnogo klassa 361K (An objective method of image shape control during mutual exposure of a fast aperture lens with an average angular field and a matrix radiation detector using the example of a stellar instrument of the exact class 361K), 6-ya Vserossiiskaya nauchno-tekhnicheskaya konferentsiya “Sovremennye problemy opredeleniya orientatsii i navigatsii kosmicheskikh apparatov” (6th All-Russia Scientific and Technical Conf. “Modern Problems of Determining the Orientation and Navigation of Spacecraft”), Proc., Tarusa, 11–13 Sept. 2018, Moscow: IKI RAS, 2019, pp. 213–222.