Abstract: The present invention is directed to an ultrasound imaging system and method for Doppler processing of data. The ultrasonic imaging system efficiently addresses the data computational and processing needs of Doppler processing. Software executable sequences in accordance with a preferred embodiment of the present invention determines the phase shift and the auto-correlation phase of filtered image data. In a preferred embodiment, the system of ultrasonic imaging also includes a sequence of instructions for Doppler processing that provides the functions for demodulation, Gauss Match filtering, auto-correlation calculation, phase shift calculation, frame averaging, and scan conversion implemented with Single Instruction Multiple Data (SIMD) or Multiple Instruction Multiple Data (MIMD) instructions.