Precise Point Positioning
（重定向自Precise positioning）
Precise Point Positioning is a Global Navigation Satellite System (GNSS) positioning method to calculate very precise positions up to few centimeter level using a single (GNSS) receiver in a dynamic and global reference framework like International Terrestrial Reference System (ITRS). PPP methods are different from (DGNSS) positioning methods which differentiate errors using one or more reference stations with known positions. PPP approach combines precise clocks and orbits calculated from a global network to calculate a precise position with a single receiver which can be double or single frequency.