.gps / Glonass Combined Application Issues Related To Research

GPS and GLONASS are two independent satellite navigation systems which have their own unique advantages and disadvantages respectively. However, the combination of the two satellite navigation systems—GPS/GLONASS which overcome the disadvantages of the single system at the same time will provide good prospects for application.At present, GALILEO and the second generation satellite navigation system of our country being studied will join the future navigation area. The applications of the combination of several navigation systems will be certain trend. So, the research of the applications of the combination of several navigation systems has become a hot topic in recent years. Studying on the combination systems of GPS/GLONASS take on great significance for our country to developing the second generation satellite navigation system and the combination with other satellite navigation systems. In this paper, the related problems on the applications of the combination of GPS and GLONASS navigation systems have been researched.In this paper, firstly, we introduce the structure of systems, policies, status quoes, the structure of satellite signals, and the structure of navigation message of GPS and GLONASS and make a comparison of their own differencies.Secondly, a transformation formula of time system is proposed based on the comparison of the time system difference of GPS and GLONASS.Moreover, based on the mathematic model and transformation approach analysis of the PZ—90 coordinate system of GLONASS and the WGS-84 coordinate system of GPS, we give the evaluation of acquirement of current transformation parameters and propose pseudo range technique of determining transformation parameters.After analyzing and disccussing of the difference of GPS and GLONASS pseudo range positioning, the mathematic models of pseudo range positioning of the combination of GPS/GLONASS are proposed and the measurement accuracy of pseudo range positioning of the combination of GPS/GLONASS and the single is compared and analyzed. The algorithms of RAIM are proposed by combination of GPS and GLONASS based on the concept of RAIM. Based on carrier phase measurement, the single difference and double difference measuring equation of GLONASS are proposed and compared with GPS's. The basical mthods of measuring solution of ambiguity the combination carrier phase of GPS/GLONASS are described based on the comparison of single difference and double difference measuring equation of GPS and GLONASS and the problem of phase measurement of combination carrier phase of GPS/GLONASS.Finally, the problems and solutions in GPS/GLONASS combined application are discussed and studied preliminary.