Antenna phase center effects and measurements in GNSS ranging applications

Antenna phase center offset (PCO) location and phase center variation (PCV) play an important role in high-precision GNSS ranging applications that use carrier-phase measurements. For ranging systems that use CDMA code-phase measurements, other statistics play a similar role - antenna group delay center offset (GDCO) and group delay variation (GDV). This paper describes the methods of how to measure and compute these statistics based on amplitude and phase pattern measured for a given antenna. A susceptibility analysis of these statistics versus multipath and antenna design parameters is also made. Practical examples on how to deal with undesired movement of PCO or larger variation of PCV is presented as well.