UNB 3 m模型的区域精度分析

摘要

对流层延迟是GNSS导航定位的重要误差源之一,主要受气温、气压以及水汽分压等气象参数的影响,具有变化迅速、随机的特点.本文利用分布在欧亚地区的72个IGS站提供的2015年全年的ZTD产品对UNB 3 m模型进行了详细的探讨,得出该模型在相应地区的平均偏差为0.017 m,高于北美地区0.005 m的平均偏差.本文选出了bsrt、chan、guug等8个IGS站,进一步分析比较,得出UNB 3 m模型误差在空间上的分布特性为:在高纬度地区UNB 3 m模型的适应性较好,在中低纬度地区、沿海区域精度明显低于内陆地区;模型误差的时间分布特性为:在夏季符合精度较差,但在春季和冬季符合精度较好;同时,模型的预测精度与高程并无明显的规律.本文研究还发现模型的bias与测站的水汽输送规律有明显的相关性,为进一步提高ZTD的模型预测精度提供了很好的思路和方向.%Troposphere delay is one of the main error sources in global navigation satellite systems (GNSS).It has the characteristics of rapidness and randomness on change,affected by the meteorological parameters such as temperature,pressure and water vapor.With the products of ZTD throughout the year 2015,which are supplied by the 72 IGS stations distributed in Eurasia,this paper gives a detailed analysis on UNB3m Model.The analysis shows that UNB 3 m model has a bias of 0.017 m in its area,which is higher than North America with a bias of 0.005 m.And further comparisons on the selected 8 IGS stations,the paper come out a result that the error of UNB3m model has spatial distribution characteristics:It has a good adaptability in the high latitudes;in the middle or low latitudes,the precision of the model is higher in inland areas than in coastal areas.The model also has a error distribution features of the time:it has poor accuracy in summer,but it is better in spring and winter.At the same time,the prediction accuracy and elevation of model have no obvious rule.This paper also shows the modelg bias has a clear relation with the rule of water vapor transport,which provides a good idea and direction for further improvement of the ZTD model's forecast precision.