Disclosed is an antenna calibration technique for performing absolute antenna calibration. An antenna to be calibrated is positioned in a first position, called a home position, and records data samples from received satellite signals. The antenna is then moved to another location, called a non-home position, and records data samples from received satellite signals while at the non-home position. The antenna is then returned to the home position and records additional data samples. During the time that the antenna to be calibrated is recording its data samples, an auxiliary antenna is also recording satellite signal data samples. The data samples taken by the antenna to be calibrated during the home and non-home positions are differenced with the data samples taken by the auxiliary antenna during the same time period. The differenced data are interpolated to determine, at a particular time, an estimate of what the differenced data would be if the antenna to be calibrated occupied both the home and non-home positions at the same point in time. This allows for determination of the phase center of the antenna to be calibrated by differencing the interpolated estimates.