Filtering out the noise in the observations by applying a low pass filter

Hi,

I need to filter out the nosie in my observation data. Based on my understanding, I should use Low Pass Filter function. I was wondering if someone could help me with this?

I have attached the excel file as well.

Thank you and I look forward to hearing from you.

Kind regards,

Ali

Answer 1

[Abhishek Gupta]

Hi,

As per my understanding, you want to remove noise from your data using low-pass filter. You can do the same using the 'lowpass()' function in MATLAB. See the code below: -

% Import data from excel and save it as a variable
% Load the saved variable
load('ObservationData.mat');    

signal = ObservationData.Value;  % signal vector

% Use Fourier transforms to find the frequency components of a signal buried in noise
y = fft(signal);     
f = (0:length(y)-1)*50/length(y);
plot(f,abs(y))

% Apply lowpass filter
lowpass(signal,10,1e3)

Output: -

For more information, check out the following documentations: -

1. lowpass filter
2. Fast fourier transform

[Ali Saremi]

Hi Abhishek Gupta,

Thank you so much for your help. It worked for me. Wish you a good day.

Regards,

Ali