Why?--Robert is going to guide me on helping him with Chamber Pinning investigation.  That is, does proximity to the chamber reduce wind induced tilt of the floor?

SEI is using just one of our three LVEA STS2s, ITMY (STS2B) for HEPI and ISI Sensor Correction.  So we'll move an under utilized STSs around the floor to see how distance from/to the Chamber Legs affects the tilt of the floor induced by wind.

Right now, the HAM5 machine is actually in the BierGarten a couple meters -Y of the ITMY machine; I'll call the machine in this position Roam1.  Not quite close enough for a huddle test (especially if it were windy) so I'll move it closer next week.

Meanwhile, we can compare things now to access the seismometers' health.

Had a fairly quiet wind last night so attached are low wind comparisons.

Plot1 are the X-axes.  Roam1 and ITMY compare pretty well until we get down to about 20mHz. HAM2 X may have a problem or it is just the location.  With these light winds, really less than 5mph mostly during the 5500sec spectra, it is troubling to see the ETMY X channel.  The wind is light, it is 4:30am, no reason for that noise compared to the others.

The Y axes in Plot2 reveal the good agreement between ITMY and Roam1 is now down to below 10mHz.  HAM2 again we assume is suffering either from it's location or its rough LIGO life over the years.  The End Machines compare quite well to below 10mHz as well.

The 3rd plot shows great z axis agreement between the site instruments to well below 10mHz (except maybe HAM2 again, around 5-6mHz.)  Too bad this channel wasn't the one we need for tilt studies.