Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2023, Vol. 20, No. 1, pp. 87-92
Influence of thermoelastic deformation on measurement accuracy in star orientation sensors
N.N. Brysin
1 , O.V. Philippova
1 , V.E. Shevelev
1 1 Space Research Institute RAS, Moscow, Russia
Accepted: 17.12.2022
DOI: 10.21046/2070-7401-2023-20-1-87-92
The paper considers the influence of the temperature of the stellar sensor design on the accuracy of its operation, in particular, the rotation of the internal coordinate system formed by the optical system — image receptor construct relative to the instrumental coordinate system determined by the instrument’s seating plane due to thermoelastic deformations of the stellar sensor’s structural elements. Previously, the authors investigated the effect of thermally induced deformations on the mutual angular position by means of finite element modeling. The authors have developed a technique for determining the value of the thermoelastic component of the measurement error, and the aim of the work was to carry out an experimental study of a specially made model of a star sensor according to this technique. The experimental part of the study was carried out on the previously created focusing control stand, which includes a long-focus collimator and a vacuum chamber with an external thermostat placed in it, which allows carrying out optical measurements under vacuum conditions at different seating temperatures. The experimental part consists of two experiments: one at changing the seat temperature in a narrow range, 2 C, and the other in a wide range, 60 C. The results show that when the seating temperature changes, due to thermal inertia, there is a temperature deformation associated with the presence of a temperature gradient across the device design. In a narrow temperature range of the seating, after the temperature field is leveled across the structure, the influence of thermoelastic deformations is negligible, but in a wide temperature range, the manifestation of the thermoelastic deformations becomes significant.
Keywords: star tracker, thermoelasticity, thermal vacuum testing
Full textReferences:
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