 attenuation coefficient in dB/(MHz cm), f is the frequency in MHz (chosen here as the transmit frequency), and d is the total (round-trip) distance travelled in cm. Here the distance variable is created assuming that t = 0 corresponds to the middle of the transmitted tone burst.</p>

<pre class="codeinput">
<span class="comment">% create radius variable assuming that t0 corresponds to the middle of the
% input signal</span>
t0 = length(input_signal) * kgrid.dt / 2;
r = c0 * ( (1:length(kgrid.t_array)) * kg