Comparative Analysis of Global Augmentations to the GLONASS System

. This article considers two possible directions of the GLONASS system expansion to improve the accuracy on a global scale, namely, the creation of a second GLONASS orbital constellation comprising 24 additional navigation satellites in three intermediate planes and the creation of a high-orbit augmentation to the GLONASS system comprising 18 navigation satellites with six subsatellite traces on circular geosynchronous inclined orbits with three satellites on each track. It is shown that in a wide range of shading angles the dual GLONASS has a clear advantage over the GLONASS system with a high-orbit augmentation by the maximum time fraction criterion for the provision of the guaranteed positioning precision when the position dilution of precision is less than 6. Based on the available experimental data of high-orbit spacecraft launch using upper-stage rockets, it is shown that doubling the GLONASS grouping has lower costs than creating a global high-orbital satellite augmentation. The dual GLONASS has a three times lower dispersion in positioning accuracy at different longitudes with the same latitude of the observation point than the GLONASS with a high-orbital augmentation. The paper proposes a method for augmentation of the GLONASS orbital constellation by using additional distance-measurement maximum length sequences having a low cross-correlation with the current distance-measurement code.