Disclosed is a system and method for determining the far-field radiation pattern of an antenna within a composite radiator. The method involves performing a near-field scan at an angular sample spacing corresponding to a minimum sphere centered at the crossing of two rotational axes encompassing the composite radiator, computing coefficients based on the near-field scan, adding a phase adjustment to the far field based on a translation from the scan origin to a point within the antenna, re-computing the coefficients, and truncating the re-computed coefficients, thereby retaining a number of coefficients corresponding to the diameter of a minimum sphere encompassing the antenna only. In doing so, the far-field radiation pattern of the antenna may be determined from the truncated set of coefficients with interference effects of the composite radiator substantially mitigated.