The tendency
is toward this shape when simple phase correction is
used, such as the m-derived filter with m greater than
one. The pairs of echoes are those of n = 2 and 4 in
Fig. 6. The peak values of the components of the
phase distortion b' are respectively 1/2 and 1/4
radian, so the amplitudes of the echoes are, respectively,
1/4 and 1/8