Next: Simulated Results with Up: Assessment of Methods Used Previous: Introduction . ... Then one has to use regularized inversion methods in order to obtain approximate and sensible solutions. ... All these methods contain a free parameter which is the so-called regularization parameter; in the case of method ( ) this is a smoothing of the higher spatial frequencies; for the methods ( ) - ( ), it is the number of iterations. ... In the case of method ( ) the iteration scheme is given by . ...