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Reports until 08:21, Tuesday 14 April 2015
H1 AOS (ISC)
edward.daw@LIGO.ORG - posted 08:21, Tuesday 14 April 2015 (17855)
Instructions for acquiring broadband power spectra and cross correlation / coherence data from OMC DCPD, REFL_AIR Q90
Ross Kennedy & Ed Daw

Instructions for acquiring 100kHz bandwidth ASD, cross correlation, and cross spectral density measurements with 100kHz bandwidth.
1. Check that the LVEA SR785 in the LVEA is hooked up to the OMC DCPD whitening preamplifier pick-off (channel A) and the long RG-58 cable back to the REFL 
electronics (channel B). I left it hooked up when we departed, but it might have been disconnected, I guess. Check also that the GPIB and wireless internet box are connected and powered up.
2. On a control room machine, cd to /ligo/home/controls/edaw_work/hfross
3. Do ./SR785broadscan
- this generates a sequence of measurements covering DC-102.5kHz in 16Hz bins. There are four resulting plots, in order, ASD from the OMCDCPD1, ASD from REFLAIRQ90, cross correlation density from both ports (note that this is per Hz over 16Hz bins, so multiply by 16 to obtain cross correlation on the usual 0-1 scale), PHASE of the cross spectrum
between OMCDCPD1 and REFLAIRQ90 (mainly useful to see the noise in the phase disappear at frequencies where there is extensive cross correlation. 
Results appear in the saved_data subdirectory. Text files of data are saved there too for more detailed information on line frequencies.
Let me or ross know if this doesn't work - we can probably help fix it.
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