精密单点定位模糊度快速固定算法

摘要

精密单点定位非差模糊度解算和收敛时间是制约其应用和发展的主要因素.本文从基本观测模型出发,将消电离层模糊度分解为宽巷和窄巷分别固定,并对固定方法做了改进,削弱了初始历元相关性对收敛速度的影响；提出非差相位延迟估计(PDE)解算模型,在不利用区域或全球参考站的前提下解算卫星与接收机相位延迟.通过对中国6个IGS站数据处理结果显示,93％的模糊度可以在20min内固定.固定后定位精度在E,N和U方向上分别提高了63％,53％和24％；定位精度可以达到毫米至厘米级.对于数据质量较好的站点(如上海站)平面精度可达3mm,模糊度固定后精密单点定位有了很大提高.%Integer ambiguity resolution and convergence time have restricted the development and application of precise point positioning(PPP).In this paper,proceeding from the basic mathematical model of GPS observations,the ionosphere-free ambiguity was divided into wide-lane and narrow-lane to fix them separately.For orientation epoch correction,the fixing method had been improved.Zero-differenced phase delay estimation(PED) model was proposed which could compute the phase delay between satellites and receiver without using regional or global reference stations.The experiment results showed that:using the six IGS tracking stations in China,93％ of the ambiguities could be fixed within 20 min and the accuracy in E,N and U had been improved 63％,53％ and 24％.For most of the stations,millimeter to centimeter positioning accuracy could be got.What' s more,it was also demonstrated that,for some stations such as SHAO,the accuracy could reach millimeter level in horizontal due to high observation quality.