http://www.k-wave.org/forum/topic/attenuation-of-lower-frequencys-in-lossy-media Support for the k-Wave MATLAB toolbox en-US Wed, 13 May 2026 03:50:19 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/attenuation-of-lower-frequencys-in-lossy-media#post-5804 Wed, 04 Jan 2017 14:34:27 +0000 Bradley Treeby 5804@http://www.k-wave.org/forum/ <p>Hi Tobias,</p> <p>Practically, I haven't worked much with power law values outside the range seen in biological tissue, where 1 &lt;= y &lt;= 2. I agree that in principle, it should work.</p> <p>Using the Modelling Power Law Absorption Example with the <code>alpha_power</code> values set to 0 seems to give approximately the correct behaviour (remember to change the <code>example_number</code> at the beginning of the script). What happens if you adjust this example to use the frequency range and sampling parameters you're interested in?</p> <p>It could also be a issue related to how you're sampling or processing the data.</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/attenuation-of-lower-frequencys-in-lossy-media#post-5792 Thu, 22 Dec 2016 08:40:31 +0000 weigler 5792@http://www.k-wave.org/forum/ <p>Hi all,</p> <p>I'm simulating simple wave propagation in lossy media. A single source is emitting a sinusoidal signal which is meassured with to sensors in some distance from the source. Said sensors are 1m apart from each other.<br /> The maximum frequency is at 3kHz.</p> <p>Choosing medium.alpha_coeff = 0.1 and alpha_power = 0 should lead to 10dB attenuation between both sensors. This seems to be true for frequencys between 300Hz and 3kHz. Below 300Hz the attenuation drops rapidly.</p> <p>Can anyone explain this behaviour? Is it possible to turn off frequency dependence by choosing y=0 at all, as the formula suggests?</p> <p>Thanks a lot and merry Christmas to all of you<br /> Tobias </p>