Research and verification of the autonomous navigation technology of GNSS

Abstract

This paper discusses the important role of autonomous navigation capability in the development of Global Navigation Satellite Systems (GNSS) based on the current status of major GNSS designs. The architecture design for autonomous navigation by a GNSS, mainly comprising the system composition and operational process, is discussed in detail. The key technology that maintains the time and spatial reference of an autonomous navigation system is also discussed. This paper then studies the filtering algorithm, the filtering state noise covariance matrix, and the processing method of satellite-borne data based on inter-satellite observations. It also proposes a semi-autonomous navigation method based on ground observation data (anchor stations), and compares the performances of automatic navigation with different layouts and numbers of anchor stations and different observation periods. The autonomous navigation performance was evaluated in a ground-simulation test system under different GNSS deployment stages and operation modes. The accuracy of orbit determination and time synchronization of GNSS were then verified in fully autonomous and semi-autonomous navigation modes. The results provide an important reference for automating the navigation service of GNSS.