Understanding geometry specific correction factors in ANSI C63.5

Geometry-Specific Correction Factor (GSCF) methods were first introduced in the draft standard ANSI C63.5 in 2000, and have been included in the published standards since 2004. Most users of the standard should know by now the mechanics and steps involved in using GSCFs for site validation tests. However, the underlying physics is perhaps yet to be fully understood by many in the EMC community, as evidenced by several recent publications on the topic. This paper shows the derivations of the GSCFs, and their relationship to the mathematical model and physical quantities measured. It shows that the Smith model (based on the point dipole concept) is entirely bypassed. In addition, when numerical GSCFs are unavailable, the measurement approach outlined in ANSI C63.5-2006 Annex H is the same as site comparisons. The users in this case compare the site under test to a reference site.