The GLONASS System – An Overview

The principal characteristics of the GLONASS system, its current status and deployment outlook are considered. Comparison of the main characteristics of the GPS/GLONASS systems from the user's viewpoint is made. Proposals focused on the operations to be carried out to improve navigation determination accuracy for the users, provided with the combined equipment, are given. The data presented, received simultaneously on the user&s GLONASS equipment and a GP–500 GPS system, indicate that navigational determination accuracies of both systems are approximately equal. The key characteristics of 6–channel user facilities for civil aircraft and helicopters are presented. This equipment has been developed in the Institute of Space Device Engineering (ISDE) in accordance with a standard draft ARING on the combined system. The principal directions of the accuracy characteristic of the GLONASS system updating are considered. It is suggested to use the quantum–optical measurements on the Etalon satellite, launched into GLONASS satellite orbit, so that ephemeris information can be improved. The questions concerning supplying the system integrity and differential corrections information are discussed. It is proposed to combine the global system of integrity signal generation and transmission with differential corrections for regional systems. The version of the information frame developed in ISDE and intended for transmission of this information to users via geostationary satellites by means of signals similar to GPS/GLONASS, and without additional complication of user equipment, is presented here.