The parameters of models (2) and (3) defined in the calibration process are taken into consideration in the algorithm for computing system output angles according to formula (1). In order to define the parameters of model (2), the system was rotated with equal angular intervals, controlled on the basis of gyro wave rotation(5°), with estimation of wave drift rate magnitude at each angular position. Data obtained during the calibration of HRG no. 25 are presented as an example.Figure 5 shows the dependence of the gyro drift rate in the geographic coordinate system on the angular position of a wave with respect to the casing.