The paper considers one of the ways to improve the global navigation satellite system (GNSS) GLONASS by introducing into the regular constellation of navigation spacecraft (NSV) a high-orbit segment of satellites, for which the height at apogee significantly exceeds the height at perigee, as well as satellites with geosynchronous orbits. Such improvement of the space constellation of the navigation system allows to achieve an increase in the quality of navigation information for consumers. The issue of using inter-satellite measurements (ISM) with the aim of increasing the information content of trajectory measurements of satellites is considered. This achieves a reduction in the time interval between ephemeris-temporal support (ETS) bookmarks to 2 hours. The influence of factors of relativistic and non-relativistic nature on the ephemeris-time parameters of the high-orbit space complex (HEC) is considered, where special attention is paid to the influence of the gravitational potential.