Reports until 11:32, Wednesday 29 March 2017
H1 SEI
hugh.radkins@LIGO.ORG - posted 11:32, Wednesday 29 March 2017 (35186)
Report on Position Roam1 for Chamber Pinning Study

Last night we had some decent winds so here is a comparison of the ITMY STS (STS2-B) and the HAM5 STS (STS2-C) with STS2-C at the Roam1 location--guess I'm going to have to make a drawing.

Spectra starting at 1845 UTC 28 March, winds pretty steadily above 15mph with gusts to 30, from 30 to 50 degrees (hitting the SW corner of the LVEA building.)  This wind state was pretty consistent for nearly four hours; more than enough for ten 1mHz averages.  See attachment the first.

The second attachment are X Y and Z spectra plots comparing the STS2 B & C during the windy period last night and a calm reference time of March 24--seen also in aLog 35075. The Reference traces are from the quiet time and the current traces are from last night. Notice the change in the microseisms especially the primaries (around 60mHz) and how the tilts impacting the X & Y traces pretty well obliterates this primary.  Is that the tertiary showing in the references around 0.18Hz?  Sorry about the cryptic title: CurrWind 20 Y-X means the current wind is 20mph from the +Y - X direction (45 dataviewer degrees or true South [for LHO]).

Not sure what to say about the differences in the Z signals between 1 & 7mHz during the windy time...  But, as for X & Y tilt susceptibility of the ITMY and the Roam1 positions, I'd say they are the same.  Time to move to Roam2.

Images attached to this report