Abstract: A method for measuring Doppler ultrasound information transmits a transmit beam having a frequency dependent focus in which low-frequency components of the transmit beam are focused at long ranges and progressively higher frequency components of the transmit beam are focused at progressively shorter ranges. Beamformed receive signals are generated in response to receive signals from the transducers, and these beamformed receive signals are applied to Doppler processors. The frequency dependent focus of the transmit beam provides a transmit beam that is more uniform in width and intensity, and the Doppler processors thereby provide an improved Doppler image signal.