The present invention relates to a speed measurement system allowing the relative speed V of a moving body in relation to an ambient air mass to be measured independently of the atmospheric conditions, the moving body being designed to move at least at subsonic and transonic speeds. The design of the first portion of the casting conduit prevents the metal, as it cools and contracts through the conduit, from detaching from the walls, and in particular from the edges, of the mold, thus enabling an increase in casting speed with no fall in product quality. The method comprises the steps of receiving a synchronization signal, calculating first correlations and second correlations as well as determining the at least one cell-identity. The nonuniform electric field is used to modulate the kinetic energy of the ions generated in the plasma which strike the thin film’s surface.