GAMIT 10.71 resolution GNSS long baseline precision analysis

GAMIT／GLOBK has released the latest version of 10.71 on March 9,2020,mainly adding BDS-3 data processing and solar pressure model.This article uses GAMIT10.71 software,combined with the old version (GAMIT10.7_2019／09／14),to process the GNSS data of 35 MGEX (Multi-GNSS Experiment) tracking stations on the 51st to 60th days of 2020 in the world. The square root error(NRMS),baseline repetition rate,baseline mean square error,baseline solution accuracy and point accuracy are compared and analyzed for GPS and BDS solution results.The experimental results show that the root-mean-square error of each solution can reach an accuracy of less than 0.22;the GPS baseline repetition rate is slightly better than BDS.The relative and absolute baseline repetition rates of the old and new versions of the long baseline are both accurate which can achieve 1×10^-9 and 1×10^-2 respectively;the new version of the baseline length calculation accuracy and the adjustment result of many days are slightly better than the old version,and the adjustment result of many days GPS accuracy is slightly better than BDS;Overall test shows that the new version of GAMIT software has a better performance.But for the accuracy of the single BDS system,there are still many problems worth discussing.