Volume scanning along different planes is provided using angling of the elements. Rather than orthogonal dicing of the slab, kerfs are formed at non-parallel and non-perpendicular angles to the azimuth axis of the array or longitudinal axis of the slab. Apertures formed from selected groups of the angled elements and/or parts of angled elements may be used to steer along planes that extend at an angle of 5 degrees or more away from the azimuth or longitudinal axis. By walking the aperture, different parallel planes are scanned with a one-dimensional array of elements.
