Известия Томского политехнического университета: Инжиниринг георесурсов (May 2019)
On the issue of controlling the time-frequency parameters of GLONASS navigation field
Abstract
For users who work in the field of geology and geodynamics, exploration and production of natural resources, development of oil and gas fields in the areas of coastal shelves, the use of high-precision navigation measurements is the promising direction. The requirements of this circle of special of consumers to the accuracy and quality of navigation-time support is constantly increasing. Increase in accuracy and reliability of navigation measurements can be achieved by solving the problem of controlling the parameters of instability of onboard clocks in navigation satellite systems GLONASS, that makes this work relevant. The main aim of the study is to estimate the instability parameters of onboard clocks GLONASS constellation, determining to a large extent the quality and accuracy of coordinate-time definitions based on satellite navigation technology. The methods used in the study: method of excepting ionospheric delay by dual-frequency measurements, method for estimating the phase ambiguity, H. Hopfield method to compensate the tropospheric delay, method of statistical estimation of navigation clock setoff in the board satellites by the results of trajectory measurements. The results. The authors have proposed the method for estimating the setoff of onboard clock of navigation satellite GLONASS on the basis of hardware-software complex of metrological point the State service of time and frequency at the Research Institute of Metrol gy «SNIIM». The authors pay the main attention to the use of phase pseudo-distance measurements in estimation algorithm as the background information. The typical features of application of such measurements, in particular, the problem of phase ambiguity solution are selected and described. To obtain the high-precision results, the authors used the algorithms for pre-processing the pseudo-distance measurements to reduce the noise level, use of compensatory amendments to ionospheric and tropospheric delays of a navigation signal. The results of the research are the estimates of onboard time scales offset of the GLONASS constellation and statistical characteristics of the scales representation errors using time-frequency corrections. The advantage of the method is the achievement of high precision due to the use of public secondary standard time, frequency and the time scale VET 1-19. The assess obtained by the authors make the basis for controlling time-frequency parameters of GLONASS navigation field, that is one of the tasks of the State Service for metrological point of time and frequency. The conclusions: The authors propose to use the methods for controlling time-frequency parameters of the GLONASS satellite navigation in order to improve precision characteristics of corrective amendments formed by the network of active base ground stations in Novosibirsk region.
