一种机载GNSS高精度定位算法

提出部分模糊度固定的加权电离层模型提高大范围全球卫星导航系统(GNSS)航空定位的精度、可靠性及连续性.该方法的主要思路包括:自适应调整大气扰动等误差影响以实现短基线与长基线两类解算模式之间的灵活切换;施加虚拟电离层观测约束信息,提高基线动态定位的浮点解精度;采用部分模糊度固定方法有效挖掘若干模糊度参数的整周约束.试验表明,提出的方法可提高模糊固定效率与定位精度,克服传统方法有效观测信息利用率不足、定位精度较差、可靠性不高以及连续性较差的问题.实验结果表明,部分模糊度固定算法可在2 min内固定95%以上宽巷模糊度解算与80%以上窄巷模糊度,约20 min后可固定所有模糊度.

A method to high precision positioning based on airborne GNSS data

The ionosphere-weighted model with partial ambiguity resolution(PAR) strategy is proposed to improve the performance of airborne GNSS kinematic positioning: 1) The proposed model is flexible enough for short／long-range kinematic positioning through adaptive ionospheric and tropospheric estimation; 2) The virtual or pseudo ionosphere observation equations are introduced to enhance the model strength; 3) When full ambiguity resolution(AR) is unavailable, an alternative selection is provided to make the best use of integer constraint information. The proposed model is tested with real airborne GNSS kinematic positioning data. Both the AR efficiency and reliability is improved obviously with enhanced model strength and better float ambiguity solution, therefore kinematic positioning results show improvement in precision, reliability as well as the continuity of precision. Test results show that the wide-lane and narrow lane ambiguity fix rate is over 95％ and 80％ respectively within 2 minutes data.