I measured the bounce/roll frequencies for all the optics, and updated the Mechanical Resonances wiki page accordingly.
I put the DTT templates I used in the /users/Templates/DTT_BounceRoll folder; I wrote a python script which takes the exported ASCII data from such templates and does all the rest; the only tricky part is to remember to export the channel data in the order "UL UR LL" for each optic; the ordering of the optics in a single template export is not important, as long as you remember it...
Anyhow, the script is documented and the only things that may need to be modified are:
- lines 21, 22: the "starting points" FREQ_B and FREQ_R (to accomodate noisy or bad data, as ETMX was for the Roll part in both the measurements I took);
- line 72: the parameters of the slepian window used to average the data: the first one is the most important and indicates how much averaging will happen; more averaging means less noise but broader and lower peaks, which shouldn't be a big issue since we care only about the peak position, not its amplitude; however, if the peak is already shallow, too much averaging will make things worse instead of better;
- lines 110, 118: the initial guess for the fit parameters;
The script is in scripts/SUS/BR_freq_finder.py and in the SVN. I attach the plots I made with this method.