On ionosphere-delay processing methods for single-frequency precise-point positioning

:In single-frequency precise-point positioning of a satellite, ionosphere delay is one of the most important factors impacting the accuracy. Because of the instability of the ionosphere and uncertainty of its physical properties, the positioning accuracy is seriously limited when using a precision-limited model for correction. In order to reduce the error, we propose to introduce some ionosphere parameter for real-time ionosphere-delay estimation by applying various mapping functions. Through calculation with data from the IGS (International GPS Service) tracking station and comparison among results of using several different models and mapping functions, the feasibility and effectiveness of the new method are verified.