title: Remove noise from accelerometer data
body: <p>I have data from an accelerator which is a bit noisy (as it seems to me). The manufacturer states the noise spectral density as 45 micro g /(Hz)^0.5.</p>
  
  <p>How do I use this information to remove noise from the time signal. I don't have a signal processing background. So can anyone point me to a source where I can find how this problem can be handled.</p>
  
  <p>Thank you all.</p>
  
  <p><a href="https://i.stack.imgur.com/wJJHN.png" rel="nofollow noreferrer">The acceleration signal and its frequency content look like this</a></p>
  
  <p>I used the algorithm mentioned here but I doesn't seem to work for me. I found the following code at a blog. Do you think it is implemented correctly? I have tried to vary my cutoff frequency, but the noise is still there</p>
  
  <pre><code>def lpf(x, Fc, Fs, x0 = None): 
       alpha = 1 - exp(-2.0 * pi * Fc / Fs) 
       y = zeros_like(x) 
       yk = x[0] if x0 is None else x0 
       for k in range(len(y)): 
           yk += alpha * (x[k]-yk) 
           y[k] = yk 
       return y 
  </code></pre>
  
  <p>The noise seems to be randomly distributed and not in particular range of frequencies.</p>