一种整数相位钟法精密单点定位模糊度固定模型

A Precise Point Positioning Ambiguity Fixed Model Based on Integer Phase Clock

星间单差法是常用的精密单点定位PPP模糊度固定方法,但是要面临基准星转换的问题。为此,提出了一种逐级模糊度固定模型,采用法国CNES发布的整数相位钟差产品,在PPP非差观测模型基础上逐一选取两颗卫星进行模糊度固定;得到多组单差模糊度固定解后,再以此构成约束条件进行滤波得到其他参数。实验选取了8个IGS站共48个观测时段进行模糊度固定实验。结果表明,模糊度成功固定后,位置三维误差平均值由5.60 cm减小到2.72 cm;位置误差标准差由3.64 cm减小到1.50 cm。仿动态条件下,模糊度固定后位置误差由6.02 cm降至4.75 cm。

Satellite single difference is a commonly used PPP ambiguity fixed method,but it faces the problem of reference star conversion.In order to conquer the problem,a cascaded ambiguity fixed model is proposed in this paper.The model is based on the integer phase clock difference product released by CNES in France.Using PPP zero-difference observation model,two satellites are selected one by one to fix the ambiguity.After obtaining multiple fixed solutions of single difference ambiguity,they are constituted a constraint to filter so as to obtain other parameters.Experiments are carried out on a total of 48 observation periods of 8 IGS stations for ambiguity fixation experiments.The results show that after the ambiguity is successfully fixed,the average value of positional three-dimensional error is reduced from 5.60 cm to 2.72 cm,and the standard deviation of position error is reduced from 3.64 cm to 1.50 cm.Under simulated dynamic conditions,the position error is reduced from 6.02 cm to 4.75 cm after the ambiguity is fixed.