Abstract:Taking into account the low temporal-spatial resolution of the existing ZTD and ZWD vertical profile model, we analyze the temporal-spatial distribution characteristics of ZTD and ZWD height scale factors in China based on the 2014-2016 meteorological reanalysis data MERRA-2 provided by NASA. The results show that both ZTD and ZWD height scale factors have obvious annual and semi-annual changes, which are significantly correlated with longitude and latitude, and the temporal-spatial distribution characteristics of ZTD and ZWD height scale factors are significantly different.