AbstractReal radar echo signals of a pedestrian, vehicle and group of helicopters are analyzed in order to maximize signal energy around central Doppler frequency in time–frequency plane. An optimization, preserving this concentration, is suggested based on three well-known concentration measures. Various window functions and time–frequency distributions were optimization inputs. Conducted experiments on an analytic and three real signals have shown that energy concentration significantly depends on used time–frequency distribution and window function, for all three used criteria.