Method and algorithms for minimizing temperature errors of spacecraft fiber-optic gyroscopes

The calculation method and algorithms used to calibrate fiber-optic gyroscopes installed in instrument clusters of artificial Earth satellites are described. A mathematical statement of the problem of non-stationary heat transfer is given. The considered problem is solved using a combination of the Finite Element Method and the Finite difference method of time integration. Thermal changes that occur in the satellite body during its motion in near-Earth orbit are considered and modeled. The temperature distributions in the satellite body and directly in the fiber-optic gyroscope are determined. The found distributions was used to substantiate the requirements for ground-based calibration of gyroscopes in order to build the corresponding compensating models. In addition, the obtained dependence of temperatures on time is used for operation algorithms under conditions of gyroscope temperature uncertainty, for example, due to a temperature sensor failure. Thus, a new approach to minimizing the temperature error of instruments as part of onboard orientation and navigation systems, which increases their fault tolerance, is presented.