The invention provides an enhanced method and system for non-invasive analysis of a target. The enhancement includes increased analytic power derived from creating a complete representation of a target using less than complete information. The invention provides a non-invasive analysis system and method that includes generating and exploiting a system model that includes a target model that accurately represents the interaction of radiant energy with a target.In a preferred embodiment according to the invention, a digital signal processor compares signals acquired from an actual non-invasive system with theoretical signals generated using the system model, identifies the target model that matches most closely, and outputs target characteristics, including target attribute of interest.
