Errors from antenna phase center, known as PCV - Phase Center Variations - are considered a limiting agent of the relative GNSS positioning and the Precise Point Positioning (PPP) accuracy. The PCV are dependent of the direction of the satellite signal and can be modeled by parameters determined by antenna calibration, a whole process enclosing measurements but also specific softwares, for example WaSoft/Kalib. Authors state that some algorithms apply spherical harmonic functions to describe PCV parameters. But there are no certain information about which coefficients are taken in the modeling. In this research, PCV parameters of the LEIAX 1202GG antenna derived by the WaSoft/Kalib software are applied to an antenna calibration process. The main goal is to calculate spherical harmonic expansion coefficients, a nm and b nm to be applied on a new determination of PCV and PCO parameters. A comparison to the values obtained by a commercial software Wasoft/Kalib is carried out. The new and the original parameters are utilized to compute geodetic coordinates of two stations in order to be compared. Tests for two different base lines were realized. Sub-millimetric and millimetric deviations were found for PCV and for the UP component, respectively.
Phase Center Variations; Spherical Harmonics; WaSoft/Kalib
