不同气候条件下几种对流层模型性能分析

Performance analysis of several tropospheric models under different climatic conditions

对流层延迟是全球卫星导航系统(GNSS)高精度定位测量的重要误差源之一。鉴于对不同气候条件下对流层模型性能分析不足,针对高压低温低湿、低压高温高湿气候条件,通过相对动态定位实验来比较萨斯塔莫宁(Saastamoinen)、改进霍普菲尔德(M-Hopfield)、新布伦瑞克三代(UNB3)这三种对流层模型精度并分析其适用性能。实验结果表明:低压高温高湿环境下,坐标偏差序列波动相对剧烈且在垂直方向上多峰值,各模型坐标解算精度相对更低且模型间精度差异更大,UNB3模型整体改正效果更好。高压低温低湿环境下,Saastamoinen模型更为适用,在垂直方向上表现显著,M-Hopfield模型次之。气象因子(气压、气温、相对湿度)影响对流层延迟量且气压影响程度相对低于气温与相对湿度。高压低温低湿环境下模糊度固定率高出约15%,UNB3模型定位的模糊度固定率高于Saastamoinen与M-Hopfield模型,且后两种模型的模糊度固定率相差不大。

Tropospheric delay is one of the most important error sources of high precision positioning measurement in Global Navigation Satellite System(GNSS).Aiming at the insufficient analysis of the tropospheric model performance under different climatic conditions,this paper carried out relative kinematic positioning experiments to determine the applicability of different tropospheric models and evaluate the accuracy of three tropospheric models including Saastamoinen,Modified Hopfield(M-Hopfield)and University of New Brunswick 3(UNB3).The experimental results showed that:Under the conditions of low pressure,high temperature and high humidity,the fluctuation of coordinate deviation sequence was relatively violent and had multiple peaks in the vertical direction.Besides,the coordinate solution accuracy of each model was relatively lower and the accuracy difference between models was larger,and the overall correction effect of UNB3 model was better.Under the conditions of high pressure,low temperature and low humidity,Saastamoinen model was more suitable,especially in the vertical direction,followed by M-Hopfield model.Meteorological factors(air pressure,air temperature and relative humidity)affected the tropospheric delay,and the degree of influence of air pressure was relatively lower than that of air temperature and relative humidity.The fixed rate of ambiguity under the conditions of high pressure,low temperature and low humidity was about 15%higher.In addition,the fixed rate of ambiguity of UNB3 model positioning was higher than that of Saastamoinen and M-Hopfield models,and the fixed rate of ambiguity of the latter two models had little difference.