Analysis of the Effect of Tropospheric Delay on Orthometric Height Determination at High Mountain

Abstract

The purpose of this study is to precisely determine the orthometric height considering tropospheric delay at the top of the mountain where the height difference with reference ground surface is large. So, GNSS surveying was carried out at Cheonwangbong on Mount Jiri to determine the orthometric height, and GNSS data were processed by both DGNSS and PPP methods to determine ellipsoidal height using Bernese version 5.0 software. In this process, KNGeoid14 Korean geoid model was used and the effects of troposphere delay on the coordinates and orthometric height were analyzed. The study results showed that the tropospheric delay was reduced by 3.04 cm with every 100 m increase of the ellipsoidal height. The orthometric height and RMSE determined by the DGNSS method were found to be 1915.4596 m and 0.0520 m, respectively, and the orthometric height and RMSE determined by the PPP method were found to be 1915.4059 m and 0.0527 m, respectively. So, the difference between the DGNSS method and the PPP method when tropospheric corrections were applied showed a difference of 5.37 cm in orthometric height. And, the results also showed that the difference in whether or not the tropospheric delay model was applied in the calculation of the orthometric height was 1.53 cm in the same DGNSS method.