Difficulties and solutions for estimating transport by perturbative experiments

The first part of this work reviews the algebraic matricial approach to transport data inversion. It works for the convection-diffusion transport equation used for periodic signals and provides a formally exact solution, as well as a quantitative assessment of error bars. The standard methods of reconstruction infer the diffusivity D and pinch V by matching experimental data against those simulated by transport codes. These methods do not warrant the validity of either the underlying models of transport, or of the reconstructed D(r) and V (r), even when the results look reasonable. However, the adoption of automated global search algorithms based upon genetic algorithms is bound to greatly increase the probability of finding optimal solutions.