基于北斗三号的大气水汽探测性能初步分析

对我国刚布署完成的北斗三号卫星导航系统（BDS-3）的大气水汽探测性能作初步分析可更好地发挥BDS-3的气象探测潜能. 采用全球不同位置的台站进行几种手段的对比，探测结果具有代表性和说服力. 研究结果表明:将BDS-3/PWV（大气可降水量）与GPS/PWV对比，平均偏差（BIAS）优于1.0 mm，均方根误差（RMSE）优于2.0 mm，相关系数均在94%以上；BDS-3/PWV与GPS/PWV求差取绝对值后的平均值（MEAN）为1.1 mm，比北斗二号（BDS-2）降低了71%；BDS-3/PWV与GPS/PWV的RMSE为1.4 mm，比BDS-2降低了63%. 将BDS-3/PWV与ERA5/PWV对比， BIAS优于2.9 mm，RMSE优于2.8 mm，相关系数均在92%以上，BDS-3/PWV与ERA5/PWV的MEAN为2.1 mm，比BDS-2降低了48%；BDS-3/PWV与ERA5/PWV的RMSE为1.6 mm，比BDS-2降低了57%. BDS-3探测水汽性能明显优于BDS-2；BDS-3水汽探测结果与GPS、ERA5再分析资料有很好的一致性. 

Preliminary analysis of atmospheric water vapor detection performance based on BDS-3

The preliminary analysis of the atmospheric water vapor detection performance of Beidou-3 global satellite navigation system(BDS-3),which has just been deployed in China,can make better use of the meteorological detection potential of BDS-3.In this paper several methods are compared using data from diffent stations around the world.The results are representative and convincing.The results of the study showed,comparing BDS-3/PWV with GPS/PWV,the average deviation(BIAS)was preferable to 1.0 mm,the root mean square error(RMSE)was better than 2.0 mm,and the correlation coefficients were all above 94%;The mean of the absolute values of the difference between of BDS-3/PWV and GPS/PWV(MEAN)was 1.1 mm,which was 71%lower than BDS-2;The RMSE of BDS-3/PWV and GPS/PWV was 1.4 mm,which was 63%lower than BDS-2.Comparing BDS-3/PWV with ERA5/PWV,BIAS was preferable to 2.9 mm,RMSE was better than 2.8 mm,and the correlation coefficient was above 92%.The MEAN of BDS-3/PWV and ERA5/PWV was 2.1 mm,which was better than BDS-2 reduced by 48%;The RMSE of BDS-3/PWV and ERA5/PWV was 1.6 mm,which was 57%lower than BDS-2.The water vapor detection performance of BDS-3 was much better than BDS-2,which was in good agreement with GPS and ERA5 water vapor detection results.