%% Clear Workspace and Close figures clear; close all; clc; %% Intialize Laplace variable s = zpk('s'); % Load data data = load('mat/data_028.mat', 'data'); data = data.data; % Time domain plots figure; hold on; plot(data(:, 3), data(:, 1)); hold off; xlabel('Time [s]'); ylabel('Voltage [V]'); xlim([0, 100]); % Computation of the ASD of the measured voltage dt = data(2, 3) - data(1, 3); Fs = 1/dt; win = hanning(ceil(10*Fs)); [px_dc, f] = pwelch(data(:, 1), win, [], [], Fs); figure; hold on; plot(f, sqrt(px_dc)); hold off; set(gca, 'xscale', 'log'); set(gca, 'yscale', 'log'); xlabel('Frequency [Hz]'); ylabel('Amplitude Spectral Density $\left[\frac{V}{\sqrt{Hz}}\right]$') xlim([0.1, 500]); % Scaling to take into account the sensibility of the geophone and the voltage amplifier % The Geophone used are L22. Their sensibility is shown on figure [[fig:geophone_sensibility]]. S0 = 88; % Sensitivity [V/(m/s)] f0 = 2; % Cut-off frequency [Hz] S = S0*(s/2/pi/f0)/(1+s/2/pi/f0); figure; bodeFig({S}, logspace(-1, 2, 1000)); ylabel('Amplitude $\left[\frac{V}{m/s}\right]$') % #+NAME: fig:geophone_sensibility % #+CAPTION: Sensibility of the Geophone % #+RESULTS: fig:geophone_sensibility % [[file:figs/geophone_sensibility.png]] % We also take into account the gain of the electronics which is here set to be $60dB$. G0_db = 60; % [dB] G0 = 10^(G0_db/20); % [abs] % We divide the ASD measured (in $\text{V}/\sqrt{\text{Hz}}$) by the gain of the voltage amplifier to obtain the ASD of the voltage across the geophone. % We further divide the result by the sensibility of the Geophone to obtain the ASD of the velocity in $m/s/\sqrt{Hz}$. scaling = 1./squeeze(abs(freqresp(G0*S, f, 'Hz'))); % Computation of the ASD of the velocity % The ASD of the measured velocity is shown on figure [[fig:ground_motion_id31_asd_velocity]]. figure; hold on; plot(f, sqrt(px_dc).*scaling); hold off; set(gca, 'xscale', 'log'); set(gca, 'yscale', 'log'); xlabel('Frequency [Hz]'); ylabel('ASD of the measured Velocity $\left[\frac{m/s}{\sqrt{Hz}}\right]$') xlim([0.1, 500]); % #+NAME: fig:ground_motion_id31_asd_velocity % #+CAPTION: Amplitude Spectral Density of the Velocity % #+RESULTS: fig:ground_motion_id31_asd_velocity % [[file:figs/ground_motion_id31_asd_velocity.png]] % We also plot the ASD in displacement (figure [[fig:ground_motion_id31_asd_displacement]]); figure; hold on; plot(f, (sqrt(px_dc).*scaling)./(2*pi*f)); hold off; set(gca, 'xscale', 'log'); set(gca, 'yscale', 'log'); xlabel('Frequency [Hz]'); ylabel('ASD of the displacement $\left[\frac{m}{\sqrt{Hz}}\right]$') xlim([0.1, 500]); % #+NAME: fig:ground_motion_id31_asd_displacement % #+CAPTION: Amplitude Spectral Density of the Displacement % #+RESULTS: fig:ground_motion_id31_asd_displacement % [[file:figs/ground_motion_id31_asd_displacement.png]] % And also in $\frac{{\mu u}^2}{Hz}$ (figure [[fig:ground_motion_id31_psd_displacement]]). figure; hold on; plot(f, ((sqrt(px_dc).*scaling)./(2*pi*f).*1e6).^2); hold off; set(gca, 'xscale', 'log'); set(gca, 'yscale', 'log'); xlabel('Frequency [Hz]'); ylabel('PSD of the measured displacement $\left[\frac{{ \mu m }^2}{Hz}\right]$') xlim([0.1, 500]); % Load the measurement data % First we load the measurement data. % Here we have one measurement of the floor motion made at the ESRF in 2018, and one measurement made at CERN. id09 = load('./mat/id09_floor_september2018.mat'); cern = load('./mat/ground_motion_dist.mat'); % Compute PSD of the measurements % We compute the Power Spectral Densities of the measurements. Fs_id09 = 1/(id09.time3(2)-id09.time3(1)); win_id09 = hanning(ceil(10*Fs_id09)); [id09_pxx, id09_f] = pwelch(1e-6*id09.x_y_z(:, 3), win_id09, [], [], Fs_id09); Fs_cern = 1/(cern.gm.time(2)-cern.gm.time(1)); win_cern = hanning(ceil(10*Fs_cern)); [cern_pxx, cern_f] = pwelch(cern.gm.signal, win_cern, [], [], Fs_cern); % Compare PSD of Cern, ID09 and ID31 % And we compare all the measurements (figure [[fig:ground_motion_compare]]). figure; hold on; plot(id09_f, id09_pxx, 'DisplayName', 'ID09'); plot(cern_f, cern_pxx, 'DisplayName', 'CERN'); plot(f, ((sqrt(px_dc).*scaling)./(2*pi*f)).^2, 'k', 'DisplayName', 'ID31'); hold off; set(gca, 'XScale', 'log'); set(gca, 'YScale', 'log'); xlabel('Frequency [Hz]'); ylabel('PSD [$m^2/Hz$]'); legend('Location', 'northeast'); xlim([0.1, 500]);