In spectral pulsed wave Doppler imaging, spatial variance in signal and/or noise are reduced by combination of multiple spectra with at least partially decorrelated noise. Rather than requiring oversampling in time, the multiple spectra for one Doppler gate are created from different spatial signals. The Doppler gate is divided into sub-gates, the beamformed sample locations in the Doppler gate are grouped into two or more groups using any selection criterion, and/or different receive apertures are used to simultaneously sample the Doppler gate. Spectra for the gate are estimated from the samples with the different spatial content and then combined.
