http://www.k-wave.org/forum/topic/lower-limit-of-frequency-bandwidth-supported-by-a-k-space-grid Support for the k-Wave MATLAB toolbox en-US Wed, 13 May 2026 09:00:49 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/lower-limit-of-frequency-bandwidth-supported-by-a-k-space-grid#post-8852 Fri, 30 Jun 2023 02:43:15 +0000 datbui 8852@http://www.k-wave.org/forum/ <p>Hi Dr. Treeby and Dr. Cox,</p> <p>I understand that in kWave, the wave equations are discretised in time by Δt and in space through wavenumbers by Δξ; spatial gradient calculations are calculated (“sampled”) at every Δt time interval and Δξ spatial interval.</p> <p>It is straightforward to see that, with such discretisation, the supported frequency is limited to f_max = c_min/2Δξ.</p> <p>My question is, is there a lower limit of the frequency that is supported by a particular grid? In other words, let's say, the smallest non-zero wavenumber supported by the grid is Δk_ξ = 2π/(Δξ×N_ξ); would this defines the lower limit of the computational grid to f_min = c_max/(Δξ×N_ξ), considering that f = (c×k_ξ)/2π?</p> <p>I am asking this question because I am using <code>pstdElastic2D</code> code to simulate wave propagation problems in stratified media and start to observe some strange behaviours when the excitation frequency decreases under a certain limit.</p> <p>Regards,</p> <p>Dat </p>