Toward a Standard Rendering Equation for Intrinsic Earth Surface Classification

Abstract : Previous presentations have outlined the overall goals and approach for the SISO Intrinsic Earth Surface Material Classifier System project currently underway within the Office of Naval Research/SBIR Program. Recent work has focused on two aspects of the project: 1) creating the Preliminary Surface Material Standards list and 2) deriving the baseline surface rendering equation needed to translate intrinsic material properties to measured observables. This paper presents a review of the surface rendering equations, in the wavelength range from the VIS/NIR through the TIR region, used by computer simulation and remote sensing communities. We then examine the advantages and shortcomings of each candidate equation with respect to the following question - How does the candidate equation allow users to create simulated spectral information for a *natural* surface under sensor and environmental conditions typically occurring in low orbit satellite, aerial survey, remotely piloted vehicle, and ground based data sources? Along with the presentation of this equation are the definitions of the intrinsic material properties that act as input to the formula and serve as candidate intrinsic parameters for a standard objective earth surface model. Lastly we discuss the problem of mapping the equations and parameters used in the remote sensing community, where earth surface measurements take place, to those used in the computer simulation community, where a large market for realistic reproductions of earth surface images exists.