k-Wave User Forum » Topic: How can a sensor move??

k-Wave User Forum » Topic: How can a sensor move?? http://www.k-wave.org/forum/topic/how-can-a-sensor-move Support for the k-Wave MATLAB toolbox en-US Wed, 13 May 2026 01:09:43 +0000 http://bbpress.org/?v=1.0.2 <![CDATA[Search]]> q http://www.k-wave.org/forum/search.php mosina_ir2006@yahoo.com on "How can a sensor move??" http://www.k-wave.org/forum/topic/how-can-a-sensor-move#post-2574 Mon, 22 Apr 2013 16:50:54 +0000 mosina_ir2006@yahoo.com 2574@http://www.k-wave.org/forum/ can you send to me the correct code?? i need it! best regard Bradley Treeby on "How can a sensor move??" http://www.k-wave.org/forum/topic/how-can-a-sensor-move#post-2292 Tue, 16 Apr 2013 15:53:30 +0000 Bradley Treeby 2292@http://www.k-wave.org/forum/ If you know the path of your sensor through the domain (and the dependence of this on time), you can use this information to extract a single time series from your recorded data. For example, if you know your sensor is at a particular position at time t_index = 1, you can extract the value for that time index from the neighbouring grid points using linear interpolation, and so on for t_index = 2, 3, 4... For example, if you have recorded the field over entire domain, you can reshape the field at a particular time-step using something like: <code>p_field = reshape(sensor_data.p(:, t_index), [Nx, Ny]);</code> You can then extract the pressure at your moving sensor from this field using standard MATLAB interpolation tools and the current position of your sensor. Then continue to loop through the field for the entire simulation. If you don't want to store the entire field and extract the values in post processing, you could also modify the source codes directly to do this at each time step. Hope you can get it to work, Brad. mosina_ir2006@yahoo.com on "How can a sensor move??" http://www.k-wave.org/forum/topic/how-can-a-sensor-move#post-2262 Sat, 13 Apr 2013 07:59:25 +0000 mosina_ir2006@yahoo.com 2262@http://www.k-wave.org/forum/ hi, tanx for your answer. I can’t show the sensor that moves. I want to calculate the pressure in each times on the direction, but I can’t. Please check my source code!! please help me. Please!!! 'clear all; % ========================================================================= % SIMULATION % ========================================================================= % create the computational grid Nx = 64; % number of grid points in the x (row) direction Ny = Nx*2; % number of grid points in the y (column) direction dy = 20e-3/Ny; % grid point spacing in the y direction [m] dx = dy; % grid point spacing in the x direction [m] pml_size = 20; % [pixels] kgrid = makeGrid(Nx, dx, Ny, dy); % define the properties of the propagation medium medium.sound_speed = 1500; % [m/s] medium.alpha_coeff = 0.75; % [dB/(MHz^y cm)] medium.alpha_power = 1.5; % set the velocity of the moving source source_vel = 150; % [m/s] % set the relative x-position between the source and sensor source_sensor_x_distance = 10; % [grid points] % manually create the time array dt = 20e-9; % [s] t_end = (Ny - 2*pml_size - 2)*dy / source_vel; kgrid.t_array = 0:dt:t_end; % define a single source point source_x_pos = 5; % [grid points] source.p_mask = zeros(Nx, Ny); source.p_mask(end - pml_size - source_x_pos - source_sensor_x_distance, end - pml_size - Ny/4) = 1; % define a time varying sinusoidal source source_freq = 0.75e6; % [Hz] source_mag = 2; % [Pa] source.p = source_mag*sin(2*pi*source_freq*kgrid.t_array); % filter the source to remove high frequencies not supported by the grid source.p = filterTimeSeries(kgrid, medium, source.p); % define a large area detector sensor.mask = zeros(Nx, Ny); sensor.mask(end - pml_size - source_x_pos, 1 + pml_size:end - pml_size) = 1; % preallocate an empty pressure source matrix num_sensor_positions = sum(sensor.mask(:)); sensor.record = {'p_max','p'}; % assign the input options display_mask = source.p_mask ; input_args = {'DisplayMask', display_mask, 'PlotPML', false}; %run the simulation sensor_data = kspaceFirstOrder2D(kgrid, medium, source, sensor,input_args{:}); %sensor_data.p_max = reshape(sensor_data.p_max,1,num_sensor_positions); %make same size the sensor_data.p_max to source.p_mask max_pressure = zeros(Nx,Ny);' Bradley Treeby on "How can a sensor move??" http://www.k-wave.org/forum/topic/how-can-a-sensor-move#post-1844 Thu, 28 Mar 2013 08:19:24 +0000 Bradley Treeby 1844@http://www.k-wave.org/forum/ One way would be to define a binary sensor mask that traces the complete path of your moving sensor. In post processing, you can then interpolate between the recorded data from position to position. Brad. mosina_ir2006@yahoo.com on "How can a sensor move??" http://www.k-wave.org/forum/topic/how-can-a-sensor-move#post-1823 Wed, 27 Mar 2013 22:25:58 +0000 mosina_ir2006@yahoo.com 1823@http://www.k-wave.org/forum/ Hi, the K-Wave is usefull toolbox. I want to simulate a sensor is moving along a line same as "The Doppler Effect" example, but in our example source doesn't move and sensor moves. how can i do it??? best regard