GPS Satellite Clock Offset Prediction Method Based on EMD and Spectral Analysis

In the global satellite navigation and positioning system (GPS), the position measurement is achieved by time measurement. In GPS precise positioning, satellite clock of high precision and high accuracy plays a very important role. Atomic clock onboard GPS satellite is the important time reference and the core load. Clock offset directly determines the accuracy of the user's navigation and positioning. Therefore, the analysis of the characteristics of GPS clock offset and prediction methods is of great significance. This paper discusses the GPS satellite clock offset characteristics and the theory and method of prediction. Apart from clock bias, clock speed, clock drift, there is periodic terms in the GPS clock data. This paper acquires the periodic terms in the GPS clock data through empirical mode decomposition and spectrum analysis, and fit better clock model to improve the precision of the clock offset prediction.