From: Gabriela Gonzalez <gonzalez@lsu.edu>
To: S2 Data Quality Team 
Subject: Re: Data quality issues to investigate

Hi,

before Rana left LLO, we cornered him for a list of possible 
instrumental effects. Here is the list we made up, long but probably not 
exhaustive. The names refer to people who could be interested in looking 
up the particular sources, or have some expertise in the issue; however, 
nobody has started anything yet (that I know of).

Non linear couplings:

* Back up error signals to test for ADC and RF saturation. Should be
   done in all three PDs. This would catch the whitening filter
   glitches. (Brian)

* Use ifo (LSC), ASC (WFS, OptLevs), MC (for common mode) , SUS (local
   damping) control signals to test DAC saturation. Need ALL transfer
   functions to each actuator (individual coil DACs). (Rana)

* Low frequency coil driver saturation (reaching the dynamic range
   limit). (Rana)

* Using MCF for VCO overload (<10MHz). (Rana, Valera)

* Use alignment function to extrapolate unity gain in all loops, and
   set thresholds for ugf oscillations. (Gaby)

* Low frequency WFS, or ASDC (upconverted through power lines) (Vijay)

* Microseismic and earthquake amplitudes (Gaby).

* DAQ dropouts

* Lock loss: how long before the loss is the data bad? (maybe
   beginning too?)

* Violin mode ringups.

* Check calibration lines (missed samples in the EXC?)

* Sudden drops in SenseMon: what are they due to?

* Short lock segments indicating bad data: maybe from glitch rate?

Linear couplings:

* Use measured, calculated couplings from REFLI, POBI, POBQ, ASI to
   ASQ to veto glitches in these channels. (Brian, Gaby)

* HAM4 Accelerometers in ISCT4, (ISCT1 in LHO). (Robert)