http://www.k-wave.org/forum/topic/simulating-spherical-wave-with-ideal-time-of-flight Support for the k-Wave MATLAB toolbox en-US Wed, 13 May 2026 17:26:29 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/simulating-spherical-wave-with-ideal-time-of-flight#post-6455 Sun, 13 May 2018 19:57:28 +0000 Bradley Treeby 6455@http://www.k-wave.org/forum/ <p>Yes, it pads the signal. There are more details about how to control (and query) this in Section 3.7 of the k-Wave Manual.</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/simulating-spherical-wave-with-ideal-time-of-flight#post-6440 Thu, 26 Apr 2018 18:00:12 +0000 tcr11 6440@http://www.k-wave.org/forum/ <p>Hi Brad</p> <p> Shortly after posting the question I found that the problem was largely caused by a sampling error which selected the wrong point in a plane of receivers: once corrected for (and with absorption parameters undefined) it started to produce something that was more correct.</p> <p>In a related question, if an input signal was given to the kWaveTransducer source struct as a wavelet, does k-wave prepend the signal with zero values? I've noticed the TOF is still a little larger than the ideal case.</p> <p>Example: <a href="https://i.imgur.com/dpmwHVp.png" rel="nofollow">https://i.imgur.com/dpmwHVp.png</a><br /> Wavelet: <a href="https://i.imgur.com/NWyg5ks.png" rel="nofollow">https://i.imgur.com/NWyg5ks.png</a></p> <p>Cheers<br /> Tom </p> http://www.k-wave.org/forum/topic/simulating-spherical-wave-with-ideal-time-of-flight#post-6439 Thu, 26 Apr 2018 09:14:39 +0000 Bradley Treeby 6439@http://www.k-wave.org/forum/ <p>Hi Tom,</p> <p>Do you get the correct speed with no absorption (i.e., leave the absorption parameters undefined)?</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/simulating-spherical-wave-with-ideal-time-of-flight#post-6436 Wed, 25 Apr 2018 19:21:40 +0000 tcr11 6436@http://www.k-wave.org/forum/ <p>Hi</p> <p> I've setup a simple 3D k-wave simulation with a single cell point source and a full plane of receivers for an US tomography problem. Before adding extra complexity to the sim I would like to treat the medium as homogeneous with the density of water (c = 1500 ms-1), without dispersion (medium.alpha_mode = 'no_dispersion') and be able to detect the time of flight (TOF) from the source position to each point in the receive plane. However, when attempting to flatten this response for water using an ideal TOF found from the known distances and speed of sound I find that they do not match the detected TOF. How would I minimise the affect of absorption and simplify the simulation to prevent this?</p> <p>TOF mismatch: <a href="https://i.imgur.com/UEHTUI4.png" rel="nofollow">https://i.imgur.com/UEHTUI4.png</a></p> <p>All the best<br /> Tom </p>