Fast and Stable Solution Method for Angle-Resolved Light Scattering Simulation III : Handling Refractive Index Discontinuities

The change in refractive index that occurs at the interface between air and an ink-paper substrate causes effects such as refraction and total reflection. This report uses radiative transfer theory to account for these effects exactly, and for any measurement geometry, without approximations and without unknown constants. This is in contrast with Kubelka-Munk and the Saunderson correction, which is only an approximation and only for integrating sphere geometry, and which requires non-trivial determination of unknown constants. This report continues previous work, and extends the solution procedure of DORT2002 to handle a discontinuous change in refractive index at the interface between two perfectly flat layers. The result of a large number of consistency and accuracy tests are presented, and they are all positive. Some comments on planned and suggested future work are given regarding direct and inverse model development, but also for comparative studies. Comments are also given on the benefit of this work for the paper and printing industries. It is suggested that the Kubelka-Munk model should be replaced with DORT2002 in most applications