Abstract The mean frequency aliasing problem originating from the pulse repetition frequency is one of major limitations in ultrasound pulsed Doppler systems. A conventional approach to resolving this problem is to track the mean frequencies close to and beyond the Nyquist frequency along the temporal axis. In this paper, a new concept of tracking the mean frequencies along the spatial axis is proposed for the same problem. The technique is fault tolerable and more suitable for multigate and 2-D Doppler systems than conventional methods. Simulation and experimental results show that the proposed system has improved performance compared with that of the conventional systems.