Abstract: Atmospheric propagation delay is one of the main error sources for geodetic measurement.Its correction is necessary for accurate measurements.Atmospheric delay depends on many atmosphere parameters,especially atmosphere density,pressure,temperature,etc.Atmosphere parameter distribution changes with elevation angles,and so does the atmospheric delay.The total delay can be calculated from the zenith delay.The theoretic formula of the zenith delay is deduced,and a simplified mapping function for large elevation angles is proposed and compared with Mendes' new continued fraction form.The difference is less than 0.1mm for the total delay.Lastely,the system's mean total delay and its error is solved on the basis of geoscience laser altimeter system(GLAS) observation data in Antarctica,the results are 2.35m and 12mm respectively.