The META Scholar Volume 4 | Page 20

Fig. 12a Fig. 12b Fig. 13 The delay is applied according to the focus depth, figure 13 shows the time between the arriving echo front wave, figure 14 shows a wave front coming from an echo which is near the probe, in figure 15 is further, as the echo is farther from Fig. 14 the probe, the echo wave front is bigger, so the time between the wave front arrival at each crystal is shorter, in figure 16 the echo is deeper, that´s why the wave front is the biggest of three examples, and the time between the arrival of the wave fronts at the crystals is the smallest of the three examples, so there must be a different delay