[Komori, Tanaka, YokozaWashimi]

We performed the Hammering test for the IFI stack (+X, +Y side stack).

• optical table -> optical table
• top stack -> optical table
• middle stack -> optical table
• bottom stack -> optical table
• base plate -> optical table
• ground -> optical table
• nothing -> optical table (as a reference)
• base plate -> base plate
• ground (leg) -> base plate
• ground (leg) -> ground
• ground (concrete) -> ground

I estimated the transfer function from the base plate vibration to the optical table vibration, by
TF(impact@base -> ACC@table) / TF(impact@base -> ACC@base)

I also did the same calculation for the Ground (z) ->Table case, but the results became over 1 for many frequencies. I need to investigate whether my analysis is correct or not...

I'm updating the hammering test analysis.

Generally, one event should be a single pulse, and multiple pulse events due to bounding need to be removed from an analysis.

It can be realized by using a time-over-threshold (ToT) automatically. In this case, I request it be less than 0.02s.

After choosing single pulse events, the transfer functions became smooth and the coherence became larger.

Same analysis for other measurements.

I plotted the transfer functions from the impact hammer to the accelerometer, by selecting the single pulses and requesting the coherence >0.5. 
The results when the accelerometer was put on the ground were not good coherence and difficult to use.

I also evaluated the transfer functions from the Base vibration to the Table vibration, by