北斗伪距单点定位的随机模型影响评估

摘要

北斗卫星导航系统包含3种不同类型的空间星座,相对应卫星的高度角存在一定的差异,对北斗卫星单点定位的影响也不同.针对这一问题,研究了等权模型、基于卫星高度角和信噪比的北斗卫星观测量随机模型确定方法.利用MGEX站提供的观测数据,通过比较不同模型的实验结果表明:相对于等权模型,基于卫星高度角和信噪比定权模型可以提高单点定位的精度,并且信噪比模型优于高度角模型;在基于信噪比确定权阵的随机模型中,选择不同的参数,对解算结果精度会产生相应的影响.%BeiDou satellite navigation system (BDS)contains three different types of spatial constellations,and the corresponding altitudes of various constellations have some differences,of which the impact of BeiDou satellite on single point positioning is also different.According to this case,this paper has studied two methods of determination:the equal weight model,and the satellite elevation angle and the signal-to-noise ratio (SNR) model.The observation data provided by MGEX station are used to be calculated in the various models,and then analyzed and compared.It shows that:the accuracy of single point positioning can be improved by using the satellite altitude angle to respect the equal weight model,and the accuracy of the SNR model is better than the satellite altitude angle model.In the random model based on the signal to noise ratio of which the different parameters are selected,the accuracy of the calculation results will be correspondingly affected.