精密单点定位整周模糊度快速固定

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(Precise Point 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.

Rapid integer ambiguity-fixing in precise point positioning

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.