Abstract: A light beam positioning system (10) has the capability of generating accurately positioned beam paths at programmed velocities between any two positions on a target surface (18). The beam positions correspond to beam position and velocity command data processed by a system control computer (22). The invention employs an error correction processor (52) that receives X and Y position coordinate signals (X and Y signals) produced by a conventional position data generator and develops compensated X and Y position coordinate signals (X.sub.c and Y.sub.c signals) for delivery to a light beam positioner (12). The X.sub.c and Y.sub.c signals are derived from a calibration map of an addressable field representing the positions to which the light beam can be commanded on the target surface. The X.sub.c and Y.sub.c signals represent polynominal functions of the X and Y signals and offset beam position errors resulting from the light-directing properties of the system optical components (26, 28, 30).