气象参数对地基GNSS反演水汽的影响探讨

Discussion on the Effect of Meteorological Parameters on the Water Vapor of Ground-based GPS Inversion

气象参数作为GNSS反演大气水汽的重要误差源,直接影响GNSS大气遥感中PWV和ZWD的精度。为研究气象参数对GNSS探测大气水汽含量的影响,梳理GNSS探测水汽原理,针对影响PWV精度的GPT、地面观测数据RNX和ECMWF进行PWV计算;采用高精度GPS数据处理软件(GAMIT)进行数据处理,并用水汽辐射计观测的数据对GAMIT反演得到的PWV结果进行对比分析。研究发现,地面气象观测数据与高精度的水汽辐射计观测的数据拟合效果一致,ECMWF资料次之;利用地面气象观测数据可以有效保证GNSS遥感PWV的可靠性。结果表明,不同气象参数的输入带来GNSS遥感大气水汽PWV精度为1.38~1.84 mm,可满足GNSS遥感大气水汽含量的要求。

As an important error source of GNSS retrieval of atmospheric water vapor,meteorological parameters directly affect the accuracy of PWV and ZWD in GNSS atmospheric remote sensing.In order to clarify the influence of meteorological parameters on the estimation of atmospheric water vapor by GNSS,this paper described the principles of this process.Then,the effects of 4 different meteorological parameter schemes were discussed,including GPT,ground observation data RNX(RNX,VMF1),ECMWF,and PWV.The high precision GPS data processing software(GAMIT)was adopted to get the PWV,which was also compared with the observed data measured by water vapor radiometer.The results show that only RNX can be consistent with the high precision water vapor radiometer result,followed by ECMWF data,which shows that the RNX can effectively ensure the reliability of GNSS remote sensing PWV.At the same time,all the results also indicate that the accuracy PWV of GNSS remote sensing using different meteorological parameters is 1.38~1.84 mm,which fully meets the requirements of GNSS remote sensing of atmospheric water vapor content.