warmonger Support for the k-Wave MATLAB toolbox en-US Tue, 12 May 2026 23:33:00 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/grid-resolution-affects-direction-of-beamforming#post-5272 Sat, 10 Oct 2015 07:00:58 +0000 Warmonger 5272@http://www.k-wave.org/forum/ <p>Right, they are spaced by more than half a wavelength. I expected it to have lobes, but the simulation should still show the effect consistently. </p> http://www.k-wave.org/forum/topic/grid-resolution-affects-direction-of-beamforming#post-5270 Fri, 09 Oct 2015 13:01:11 +0000 Bradley Treeby 5270@http://www.k-wave.org/forum/ <p>Hi Warmonger,</p> <p>It's hard to say just looking at the pictures. Are the elements in your phased array spaced by less than wavelength/2? If not, it could be grating lobes. If you are using a linear array, you could also try comparing your code with <a href="http://www.k-wave.org/documentation/example_tvsp_steering_linear_array.php">Steering A Linear Array Example</a>.</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/grid-resolution-affects-direction-of-beamforming#post-5264 Fri, 09 Oct 2015 07:19:32 +0000 Warmonger 5264@http://www.k-wave.org/forum/ <p>Now you tell me...</p> <p>Scene<br /> <img src="http://i118.photobucket.com/albums/o102/DjFaust/Sensors_zpsonvrdtxm.png" /></p> <p>256x256, 2.5 mm pitch<br /> <img src="http://i118.photobucket.com/albums/o102/DjFaust/Charakterystyka%20256x256%202.5%20mm_zps6zuh6mex.png" /></p> <p>512 x 512, 1.25 mm pitch<br /> <img src="http://i118.photobucket.com/albums/o102/DjFaust/Charakterystyka%20512x512%201.25mm_zpsqiezdzeq.png" /> </p> http://www.k-wave.org/forum/topic/grid-resolution-affects-direction-of-beamforming#post-5262 Wed, 07 Oct 2015 21:24:42 +0000 Bradley Treeby 5262@http://www.k-wave.org/forum/ <p>Hi Warmonger,</p> <p>Unfortunately your pictures don't show up. Is it possible to upload them somewhere else?</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/grid-resolution-affects-direction-of-beamforming#post-5260 Wed, 30 Sep 2015 21:10:11 +0000 Warmonger 5260@http://www.k-wave.org/forum/ <p>I am trying to simulate phased array. However, I'm getting very firrent beam angles at different grid pitch. Here's the scene with equidistant sensor arch:</p> <p><img src="https://photos-5.dropbox.com/t/2/AABHzMXyd3jEvOHfS8OUmiMklOwaJ9vTK770tZ7_uFhfRg/12/33959423/png/32x32/1/_/1/2/Sensors.png/EL72krgCGNgaIAIoAg/qhjaAR1qPTDcBEplRF_cmY_YAgCQn3cfRFgx3aO7w2s?size=1600x1200&amp;size_mode=2" /></p> <p>256 x 256 grid with 2.5 mm pitch</p> <p><img src="https://photos-5.dropbox.com/t/2/AACcbdJnItLwRhzfSo9iXwjqcwu7YnM7mVKN6YypCvv2Gg/12/33959423/png/32x32/1/_/1/2/Charakterystyka%20256x256%202.5%20mm.png/EL72krgCGNgaIAIoAg/t9CyfxxyzQleBgxirz6am6gINxyk0psZGe3i-YwDyVU?size=1600x1200&amp;size_mode=2" /></p> <p>512 x 512 grid with 1.25 mm pitch (same physical size)</p> <p><img src="https://photos-4.dropbox.com/t/2/AADI1RM9-qqxerjKe-bI8IIaZet1MY7ZzGgrwQkaU_NMtQ/12/33959423/png/32x32/1/_/1/2/Charakterystyka%20512x512%201.25mm.png/EL72krgCGNgaIAIoAg/xlz1o3sECXE-51H7Vq8u-JPMaPZkIaRpQfJR-Wiv9Go?size=1600x1200&amp;size_mode=2" /></p> <p>The results are completely different and every beam goes its own direction I don't know why is that. Some things I checked:<br /> - Max supported frequency is higher than signal frequency (40 kHz)<br /> - Simulation sampling rate is 5 MHz so it should represent phase precisely </p>