FIG. 4.

(Color online) Field reconstruction errors (top) for the flat source (100 mm aperture) as a function of the size of the measurement region. This region is a square $2a_{\mathrm{h}}\times 2a_{\mathrm{h}}$ with its center placed on the acoustic axis at $z_{\mathrm{h}}=50$ mm. Bottom images illustrate the reconstructed source hologram in terms of velocity magnitude and phase distributions for two possible sizes of the measurement region (corresponding measurement apertures are circled).