On Monday morning, the winds were too high to make much progress locking, so Sheila and I took some time to look at optic motion when using narrow band sensor correction. Because we couldn't get very far locking, we left the optic aligned and looked at the oplev. The 3 configurations I looked at were : sensor correction using the buried seismometer, no sensor correction and sensor correction using the building seismometer. First attached plot shows the oplev pitch for the 3 configurations, red is using the buried STS, blue is no sensor correction and green is with the building STS (this scheme holds for the other plots, too). Using sensor correction definitely improves pitch at the microseism (as expected, based on my design). Using the building STS seems to do a better job of suppressing the microseism, but injects tilt below the microseism (as expected), although I don't trust the oplevs much at low frequency as length to angle coupling gets worse. Second attached plot shows the building STS spectra for the 3 measurements, mostly pretty similar, though the low frequency motion on the green trace (while using the building STS) was the worst of the 3 measurements, maybe explaining at least some of bad low frequency motion at the oplev. The last plot is the minute trend of the wind over the time of the measurement. As usual, more investigation needed. I tried a different configuration this morning, using blend with the 2 STSes. I'll post that data in a while.