The normalised logarithm of the final ICS2 objective for the three simulated measurements is shown for different hyperparameters. Different combinations of optimisation problem formulations and algorithms are shown on the ordinate, and the filter length D and filter starting points I₀, I₁ and I₂ are shown on the abscissa. Three stages are presented: The objective after 10 function evaluations (left), the objective after 50 function evaluations (middle) and the final objective’s value (right). For example, if the optimiser terminated before 50 function evaluations, the converged solution is presented in the middle plot.