Investigation of Inter-Frequency Signal Delays on Board Glonass Navigation Satellites

Abstract

The problem of inter-frequency signal delays estimation of GLONASS system navigation satellites is considered. Such signal delays in the radio-frequency channel of navigation satellites are a source of instrumental error of pseudorange measuring. A method for estimating the inter-frequency signal delays is proposed, based on the calculation of the first differences of pseudorange measurements on navigation satellites, the relative angular position of which differs by no more than 1°. An experiment on estimating the inter-frequency signal delays based on the developed method was performed. The experiment is based on the use of calibrated navigation user equipment to separate errors caused by signal delays in the receiver and the navigation satellite. Furthermore, to minimize the influence of the Earth’s ionospheric layer, only those measurements that are obtained at a low value of the total electron content (TEC) are included in the processing. Pseudorange measurements from the signals of navigation satellites of the GLONASS and GPS systems were used as the initial data. The estimation results for all GLONASS orbit group satellites were compared with the form values provided as part of the navigation frame. The results of experimental studies were analyzed and the standard deviations of the delays of GLONASS orbit group were obtained. To confirm the adequacy of the results, the internal convergence of the results was verified and the error of the developed method for estimating the inter-frequency delays of navigation satellites was determined.