The Multipath Hemispherical Map Analysis of Galileo Satellites with Long Orbit Periods

The multipath effect is one of the primary challenges preventing the Global Navigation Satellite System (GNSS) from achieving millimeter-level high-precision positioning. The Multipath Hemispherical Map (MHM) model can effectively mitigate multipath errors. Galileo satellites require data from the tenth day to correct multipath errors on the target day. However, it may not be possible to obtain ten-day data of the Galileo satellites due to the short observation time. In this study, we used measured data from consecutive days instead of the tenth day to construct a reliable MHM model of Galileo satellites. The experimental results show that the RMS reduction rate of consecutive 5-day MHM model can reach 19%, 5%, and 6% in the east, north, and upward directions, respectively. After 5-day MHM model, the RMS reduction rates of multi-day MHM models remains basically stable. Therefore, the constructed MHM model with long Orbital Repetition Period (ORP) requires at least 5 days to obtain reliable multipath correction.