Discrete direction method in nonlinear problem of incoherent scattering spectrum fitting

A new fitting technique based on functional partition by simplexes of the n th order is developed to determine ionospheric plasma parameters with spectral measurement data from the Irkutsk incoherent scatter radar. In this approach, the search for a minimum of a multidimensional functional is reduced to a minimized calculation of model functions in each iteration. The algorithm also allows simplification of the search-stop criterion.