STATUS AND PROSPECTS OF THE GLOBAL PRECISION NAVIGATION SYSTEMS (DIFFERENTIAL SUBSYSTEMS WITH THE GLOBAL WORKING RANGE)

摘要

The federal specific-purpose program «Support, development and use of the GLONASS system for 2012-2020» (hereinafter - Program) provides for development of the global system of high-precision determination of navigation and ephemeris-time information in real time for the civil customers (SHPD ETI), designed to perform the following tasks: 1. calculation of high-precision navigation and ephemeris-time information based on processing the measurements collected from the global network of measuring stations, both in real time and a posteriori modes; 2. provision of high-precision ephemeris-time information (ETI) of GLONASS and other global navigation satellites systems to the civil customers, so they can perform high-precision tasks of position determination for transport vehicles, for conducting geodetic and cartographic works and scientific basic research in the field of geodynamics, both in real time and a posteriori modes. SHPD ETI must globally provide the following levels of precision of customer's navigation: 15 cm - in up-to-date mode, 3 cm - in a posteriori mode. To meet those requirements, we have examined three variants of high-precision navigation, which can potentially provide achievement of the decimeter level of precision: 3. RTK navigation, which consists in performing a task in relative mode on the local remoteness up to 300 km from one or several reference stations; 4. SB AS navigation, which consists in performing a task in complete mode with the use of wide-area differential corrections in the wide-area system's field of action; 5. PPP navigation, which consists in performing a task in complete mode with the use of global differential corrections. As a result of the comparative analysis of highs and lows of those three ways to meet the requirements stated above (first of all, requirements for global distribution), the PPP navigation has been selected as the only way acceptable for implementation.