精密单点定位整周模糊度快速固定

摘要

提出利用GPS参考网估计电离层延迟、卫星相位偏差的算法,用于实现区域内精密单点定位(PrecisePoint Positioning,PPP)的整周模糊度快速固定.利用站间距约为100～200 km的参考网进行实验,结果表明:电离层延迟的内插和外推精度均优于1 dm,卫星相位偏差估值的日内变化不超过0.2周；此外,单天内不同时刻始,固定PPP整周模糊度所需时长最多不超过10 min,且当模糊度成功固定后,三维位置解较之相应浮点解的精度改善优于80％.新算法可望解决PPP普遍存在的收敛时间过长问题,增强了PPP技术的实用性.%In this contribution, a method of isolating ionospheric delays, Satellite Phase Biases (SPBs) from a regional GPS network is presented to enable Precise Point Positioning (PPP) with rapid integer ambiguity-fixing. Experimental results based upon a reference station network whose inter-station distances range from 100 ~ 200 km demonstrate that the interpolation and extrapolation errors of the ionospheric delays are less than 1 dm, and the intra-day variation of the SPBs is no more than 0. 2 cycles. Besides, starting from arbitrary epochs within the test day, the durations required for integer ambiguities fixing in PPP are at most 10 min, and after successful ambiguity-fixing, the obtainable accuracy of the 3-dimension positions can reach 80% improvements in contrast to their ambiguity-float counterparts. The proposed method is likely to overcome the long convergence behavior that is commonly experienced during PPP implementations and therefore promotes the practicability of the PPP.