Spectra on ETMY have been measured after implementing the damping filters recently designed (see LLO aLog 6949)

The two attached files are showing measurements respectively with the suspension damped and undamped.

For each of them, three spectra have been measured at LHO :

• In blue, old filters ISI damped
• In red, new filters ISI damped
• In green, new filters ISI isolated (only when the suspension is damped eg on the first pdf)

The improvement provided by the new filters is not visible when comparing blue and red in the first pdf since the signal is drowned in noise from 10Hz (eg p19 of […ALL_Spectra_Don.pdf] representing the motion between the structure and M0 in longitudinal). The difference seen between the two curves is certainly due to the input motion that was different for the two measurements, as we can see on the second pdf when comparing blue and red for damping off (eg p22 of […ALL_Spectra_Doff.pdf] representing roll for M0).

Although, the difference between the two states of the ISI is clearly visible on every stages of the suspension, when comparing red and green (eg every page on […ALL_Spectra_Don.pdf]). The motion (in longitudinal) between the main chain and the reaction chain at L2 stage is reduced by a factor of 100 @ 1Hz when the ISI is isolated (eg p36 of […ALL_Spectra_Don.pdf]).

The data, pdfs, and measurement list in plotallquad_spectra.m have been commited to the svn