The Antenna Phase Center in Satellite Radio-Doppler Geodetic Systems

In this paper, we consider the role of the antenna phase center in geodetic measurements based on satellite systems. To this end, we first of all clarify the mechanism through which errors arise, due to the lack of knowledge of the location of the phase center of the receiving antenna. Then, we recall briefly the procedure which can be used for finding the location of the phase center of a single antenna and we tackle the problem of finding the location of the equivalent phase center in systems consisting of two and three antennas working at different frequencies. These multiple antenna systems seem to be very promising for cutting down the errors due to the ionospheric refraction. The analytical procedure presented in the paper for solving the abovementioned problem is very general and simple and leads to results which display clearly the geometrical properties characterizing the location of the phase center of multiple antenna systems.