Approach to improve the image quality in Doppler beam sharpening

In Doppler beam sharpening (DBS), effective approach to eliminate the correlated speckle is uncorrelated accumulation to several images in the azimuth dimension. However, if the centroid of the images to accumulate has registration error, the uncorrelated accumulation will appear azimuth ambiguity. In order to reduce the azimuth ambiguity, an approach to smooth the Doppler centroids estimated from the radar returns on both the azimuth and the range dimension is present. Simulation results demonstrate that the approach improves the image quality evidently.