中国东南沿海地区PWV直接转换模型研究

Research on the Direct Conversion Model of PWV in Coastal Areas of Southeastern China

针对东南沿海地区GNSS大气可降水量(PWV)计算过程参数多、数据量大、效率不高且易产生累积误差等问题,本文基于中国东南沿海地区2017~2018年18个CORS站的GNSS数据,分析GNSS-PWV与对流层延迟(ZTD)、地面气温(T_(s))和地面大气压(P_(s))之间的线性关系,并利用多元线性拟合方法建立多因子GNSS-PWV直接转换模型,为研究区提供简捷高效的PWV计算方法。结果表明,GNSS-PWV与ZTD、P_(s)和T_(s)之间具有良好的相关性,相关系数分别为0.98、-0.65和0.78;基于ZTD、P_(s)和T_(s)的多因子PWV模型RMS为0.33 mm,精度最高,明显优于基于ZTD的单因子PWV模型(4.66 mm),而基于ZTD和P_(s)的双因子PWV模型RMS为0.50 mm。

In view of the complexity and poor performance during the real-time conversion process GNSS precipitable water vapor(PWV) in the southeast coastal area of China, based on the data of 18 GNSS stations in the area from 2017 to 2018, we analyze the linear relationship between GNSS-PWV and zenith tropospheric delay(ZTD), ground temperature(T_(s)) and ground atmospheric pressure(P_(s)). We apply the multiple linear fitting method to establish the direct conversion model of PWV,which provides a simple and effective method for predicting GNSS-PWV in the area. Experimental results show that GNSS-PWV has good correlation with ZTD, P_(s)and T_(s), their related coefficients are 0.98,-0.65 and 0.78. The multi-factor GNSS-PWV model based on ZTD, P_(s)and T_(s)has the highest precision, and its RMS is 0.33 mm. It is much better than the single-factor PWV model based on the ZTD(RMS=4.66 mm). For the double-factor GNSS-PWV model based on ZTD, P_(s)has the second highest precision, and its RMS is 0.50 mm.