摘要
针对北斗三号(BDS-3)单点定位中随机模型的适用性问题,构建了一套BDS-3伪距随机模型适用性分析方法。首先,分析了伪距噪声随卫星高度角和信噪比的变化,确定了伪距噪声与高度角及信噪比之间存在显著相关性。其次,使用最小二乘拟合法对基于正弦函数、余弦函数、分段函数、指数函数及改进信噪比函数的随机模型进行精化,以获得不同随机模型的拟合系数和拟合误差。最后,通过分析拟合误差与伪距单点定位精度两大指标,以确定适用于BDS-3的伪距随机模型。实验结果表明:BDS-3的伪距观测精度与高度角和信噪比密切相关。在不同高度角和信噪比范围内,两类随机模型对伪距噪声的精度描述能力存在差异。随机模型对定位性能的改善效果从好到差依次为指数函数、正弦函数、信噪比函数、余弦函数和分段函数。指数函数模型相比于其他4种随机模型,具有最小的拟合误差和最高的定位精度。指数函数模型相比于分段函数,在E、N和U这3个方向上的定位精度平均改进率分别为14.80%、14.01%和13.88%,定位精度的最大差异可达2.3946 m,平均差异为0.6822 m。
This paper establishes a method for analyzing the applicability of the BDS-3 pseudorange stochastic model in single point positioning.Firstly,the variations of pseudorange noise with respect to satellite elevation angle and signal-to-noise ratio(SNR) are analyzed,revealing a significant correlation between pseudorange noise and both elevation angle and SNR.Secondly,the least squares fitting method is employed to refine stochastic models based on sine functions,cosine functions,piecewise functions,exponential functions,and improved SNR functions,in order to obtain the fitting coefficients and errors for different stochastic models.Finally,the analysis of fitting errors and the accuracy of pseudorange single point positioning is conducted to identify the suitable pseudorange stochastic model for BDS-3.Experimental results indicate that the pseudorange observation accuracy of BDS-3 is closely related to the elevation angle and signal-to-noise ratio.Within different ranges of elevation angles and SNR,there are differences in the precision description capabilities of the two types of stochastic models for pseudorange noise.The improvement effects of the stochastic models on positioning performance,ranked from best to worst,are as follows:exponential function,sine function,SNR function,cosine function,and piecewise function.The exponential function model exhibits the smallest fitting error and the highest positioning accuracy compared to the other four stochastic models.The exponential function model shows an average improvement rate in positioning accuracy of 14.80%,14.01%,and 13.88% in the East,North,and Up directions,respectively,compared to the piecewise function.The maximum difference in positioning accuracy can reach 2.394 6 meters,with an average difference of 0.682 2 meters.
作者
张展鹏
刘长建
王敏
张熙
孙爽
ZHANG Zhanpeng;LIU Changjian;WANG Min;ZHANG Xi;SUN Shuang(Information Engineering University,Zhengzhou 450001,China;Key Laboratory of Smart Earth,Beijing 100080,China;61363 Troops,Xi'an 710054,China)
出处
《测绘科学技术学报》
2025年第2期140-145,共6页
Journal of Geomatics Science and Technology
基金
国家自然科学基金项目(42304043,41374041)
智慧地球重点实验室基金资助项目(KF2023YB01-11)。
关键词
北斗三号卫星导航系统
随机模型
信噪比
定位精度
拟合误差
BeiDou-3 satellite
navigation system
stochastic model
SNR(signal-to-noise ratio)
positioning accuracy
fitting error
作者简介
张展鹏(2000-),男,陕西西安人,硕士生,主要从事GNSS数据处理理论与方法研究,E-mail:zhanpeng1109@163.com;通信作者:刘长建,男,教授,E-mail:chxylcj@163.com。
