A UNIFIED FRAMEWORK FOR APPROXIMATION IN INVERSE PROBLEMS FOR DISTRIBUTED PARAMETER SYSTEMS* by

ABSTRACT 9 We present a theoretical framework that can be used to treat approximation techniques for very general classes of parameter estimation _ problems involving distributed systems that are either first or second order in % time. Using the approach developed, one can obtain both convergence and ', stability (continuous dependence of parameter estimates with respect to the observations) under very weak regularity and compactness assumptions on the set of admissible parameters. This unified theory can be used for many problems found in the recent literature and in many cases offers significant