GLONASS-K attitude: rapid turning maneuvers and other deviations from ideal yaw steering

Abstract

This paper provides a description of the GLONASS-K yaw turn maneuvers that regularly occur at orbit noon and orbit midnight when the Sun’s elevation angle relative to the satellite orbital plane is between − 2.0 and + 2.0 degrees. Formulas for maneuver modeling are presented, which can be easily integrated into any Global Navigation Satellite System (GNSS) software. Triple-frequency carrier phase observations from the global International GNSS Service (IGS) tracking network are analyzed to evaluate the performance of the model. Yaw angle estimates for the first GLONASS-K1 and first GLONASS-K2 spacecraft indicate that the actual yaw attitude follows the theoretical steering model with an accuracy of about 2 degrees. In addition to the regular yaw maneuvers, examples of other systematic deviations from the ideal GLONASS-K yaw attitude are presented.