Estimation of Geometric Factor for a User of GLONASS System with Highly Elliptical Augmentation

Movement patterns of 24 GLONASS spacecraft and 6 highly elliptical augmentation spacecraft on the Tundra and QZSS orbits are generated. The programs for calculating the influence of geometric factor on the measurement accuracy of user coordinates in various geographical points by navigation spacecraft are developed in MathCAD. Moreover, a comparison of the geometric factors for the GLONASS constellation including 24 spacecraft and 6 spacecraft on highly elliptical orbits is made. It is shown that a highly elliptical augmentation of the GLONASS system reduces the geometric factor by 20–30% during the operation within 10–20 degrees field of view and significantly improves the geometric factor during the work in mountainous and urban environment. The results obtained can be used in designing a highly elliptical augmentation for the GLONASS system.