Noise budget at lower frequency(~0.1Hz) was estimated by using seismometer's signal. At f<2Hz, the sensitivity is limited by seismic noise (attatched file 1). At f>2Hz, seismometer signal is limited by some noise so it is an upper limit, but its contribution is not big there.

Attatched file 2 is OLTF which is calibrated with UGF servo contribution (gain at f=80Hz is fitted to 1.25). Calibrated OLTF gain is a bit smaller than the measured OLTF(http://klog.icrr.u-tokyo.ac.jp/osl/?r=1456) by a factor of ~0.8. I don't know why.