Fig. 6.

Lateral beampattern simulated by Field II for two scatterers at focus, 50-mm deep, separated laterally by distances from 0.9 to 2.7 mm for the original B-scan: (a) linear scale and (b) 60-dB dynamic range. After the inverse filtering process, the width of the beampattern is narrowed, and the scatterers are separated in increments between 0.9 mm and only 1.4 mm in (c) linear scale and (d) 60-dB dynamic range. In each case (a)–(d), the amplitude in the center (0 mm lateral distance) is highest for the 0.9 mm separation and decreases in the same order as the legends.