The improvement and the effect of IERS conventions (2003)

The new generation of space datum in China should comply with the latest IERS (International Earth Rotation and Reference System Service) convention as much as possible. This paper has deeply addressed and researched the main improvements of the current version IERS Conventions (2003), including the changes of the Terrestrial Reference System, the Celestial Reference System, and the transformation between them, the tide correction and so on, which would undoubtedly benefit the realization and maintenance of our space datum. Based on PANDA (Position And Navigation Data Analyst) software developed by GNSS Center of Wuhan University, we analyzed the effect of improvements of the IERS Conventions (2003) on precise orbit determination and precise positioning. The results show that the effect of improvements of models of the coordinate transformation between the celestial and the terrestrial reference system and tide correction (including solid earth tide, ocean tide and polar tide) on precise orbit determination are 4mm, 9mm and 5mm in terms of RMS in along, cross and radial direction of the track; and the effect of the improvement of the tide models on positioning is basically under 0.6mm, and the RMS of the differences are 0.3mm, 0.3mm and 0.2mm in X, Y and Z.