The calculation of the phase center for spacecraft phased array antennas

Many distance measurement systems such as GPS require an accurate knowledge of the phase center of the system antenna. The phase center is normally thought of as the point where the phase terms of the field have minimum deviation from a spherical wavefront. In general, the phase center of an array is a rather complicated function involving array elements, array geometry, and reflection and diffraction from structures. Because of the complexity of the problem, this paper concentrates on the determination of the phase center of arrays assuming omni-directional elements.