An improved model for calculating tropospheric wet delay

Abstract A new concept is described for calculating the tropospheric zenith wet delay (ZWD) and its vertical approximation derived from the original profile of meteorological data. A new parameter of ZWD exponential decay is introduced which, together with a reference value, represents ZWD corrections accurately up to 10 km altitude. The new parameter considerably improves ZWD vertical reduction and surface ZWD calculation using the model of Askne and Nordius (1987). This development reduces the original large data set of a numerical weather model to an accurate grid representation at a reference level that may be more effectively disseminated. This can be used in regional augmentation models for precise positioning and navigation.