Fig. 6: In the first 400 milliseconds the echo of the specular reception of a first fragment is seen. Then the echo is overlaid by the leading echo and the following specular reception of a larger fragment, which follows the first one.

Fig. 6: In the first 400 milliseconds the echo of the specular reception of a first fragment is seen. Then the echo is overlaid by the leading echo and the following specular reception of a larger fragment, which follows the first one.