全球导航卫星系统（GNSS）的精密单点定位（PPP）技术，在理论研究方面有了长足的进展，但是收敛慢，严重制约它的实际应用。针对这个GNSS领域公认的瓶颈问题，从数据处理算法的角度展开研究。.首先揭示PPP滤波初期法方程严重病态，导致滤波结果波动的机理。然后通过滤波参数相关性分析，找到相关参数数量和位置，在此基础上，提出附加部分参数约束的滤波新方法；设计挖掘和利用有用的先验信息的方案，逐步提升约束初值及其协方差准确性。制订先静态后动态，先GPS再多模多頻模式，逐步推进，不断完善快速收敛算法的研究计划。 .本项研究将为PPP技术的广泛实际应用提供理论支撑，不仅是对Kalman滤波算法的改进，而且也是对数据处理理论的拓展，既有重要理论意义，也有广阔的实用价值。

The precise point positioning (PPP) technology of Global Navigation Satellite System (GNSS) has made great progress in theoretical research, but its slow convergence shortcoming seriously restricts practical application. This project will research and solve this bottleneck problem of PPP , which is recognized by the public in GNSS field, on the view of the data processing algorithm. .Firstly, the seriously ill-conditioned state of the normal equation at the initial stage of PPP filtering, which affects the parameters estimation accuracy and leads to the fluctuation of the filtering results, will be studied deeply.Based on the correlation analysis of the filter parameters, the number and their location of relevant parameters will be found, and a new filtering method adding the constraints of the part relevant parameters will be proposed. The scheme digging and using the prior information of the parameters in the system will be designed , which gradually improve the accuracy and covariance of the initial constraints. This new method can effectively reduce the ill-conditioning of the initial normal equation of the PPP filtering, and accelerate the convergence of the PPP filtering. The research plan has been formulated: firstly the static and then the dynamic models will be discussed, GPS as an example will be taken and then the multi-mode and multi-frequency model will be explored. So as to the scheme and the results will be gradually promoted the continuous improvement..This study will provide theoretical support for the extensive practical application of PPP technology. This research will not only improvement of Kalman filtering algorithm, but also expand the data processing theory. Therefore this project has important theoretical significance and broad practical value.