Message ID: 13416
Entry time: Wed Nov 8 09:59:12 2017
In reply to: 13415
Reply to this: 13428

Author:

gautam

Type:

Update

Category:

LSC

Subject:

DRMI Nosie Budget v3.1

The Oplev trace is missing for now, as I have not re-measured the A2L coupling since modifying the Oplev loop shape (specifically the low pass filter and overall gain) to allow engageing the coil de-whitening.

The averaging for the white noise TFs plotted is computed using median averaging - I have used a python transcription of Sujan's matlab code. I use scipy.signal.spectrogram to compute the fft bins (I've set some defaults like 8s fft length and a tukey window), and then take the median average using np.median(). I've also incorporated the ln(2) correction factor.

It seems like GwPy has some in-built capability to compute median (and indeed various other percentile) averages, but since we aren't using it, I just coded this up.

Quote:

why no oplev trace in the NB ?

also, this method would work better if we had a median averaging python PSD instead of mean averaging as in Welch's method.