Abstract : This document highlights a more rigorous physics-based alternative to geophysical prove-outs (GPO): Geophysical System Verification (GSV). Over the last 15 years, numerous GPOs have been performed and a significant body of knowledge has accumulated documenting technology performance. This accumulated understanding, along with the recognition that responses of munitions may be reliably predicted from physical models, presents the opportunity for both streamlining and enhancing the traditional GPO with a more rigorous physics-based approach. This document describes the physics basis of this evolution, outlines key elements of the GSV including an instrument verification strip and a blind seeding program, and presents an example of implementing this approach on a hypothetical site.