This report describes an optimization-based verification method for comparing a real-time missile model to a reference model. By using a measure of the difference of the output data of the two models, the validation task can be formulated as an optimization problem. Several different measures of trajectories are discussed. The population based stochastic global optimization method Differential Evolution is used in the numerical tests. Further, it is illustrated by examples that large difference in trajectories can be found, by the proposed method.