identifying the continuous sweep's envelope

Hi,

There is a problem identifying the continuous sweep's envelope using the Hilbert transform. Its providing lot of oscillations and there is mismatch most of the points

can you clarify with other ideas?

Thanks

% ------------------------------------------------
clear all
close all
clc

D = uigetdir(pwd,'Select Directory');

[t, X]= folder2array_V2(D,'data_Y2 (t)_Y2 (t).csv');
x=X(1,:);
Nx=length(x);


% t=1/Fs:1/Fs:length(x)/Fs;

Hx=hilbert(x); % Hilbert transform of the signal
est_env=abs(Hx); % Envelope estimation by taking the analytic signal modulus
figure(1)
plot(t,x,'linewidth',2); hold on
plot(t,est_env,'linewidth',1)
xlabel('Time (s)')
ylabel('Signal')
legend('Original signal','Estimated envelope')

Answer 1

[Daniel M]

I've had success using PaddedHilbert on the file exchange in the past. <https://www.mathworks.com/matlabcentral/fileexchange/25505-paddedhilbert>

You may also want to read this page on envelope extraction: <https://www.mathworks.com/help/signal/ug/envelope-extraction-using-the-analytic-signal.html>