Sheila, Evan, Haocun

We drove the ETM's in pitch and yaw, and took measurements for the HARD loop.

As Evan posted in aLOG 27518, the usual "IN1/IN2" method for FFT-based OLTF measurements were biased because the IN2/EXC coherences were low, so I exported the data of CLTF's using IN1/EXC (whose coherences were higher), and converted them into OLTF's.

The measurements for both pitch and yaw of CHARD and DHARD are plotted together with the modelling curved as attached:

- The measurements were taken under 2W of laser power. The blue curves are the modelling DHARD plots at 2W, and the red or orange dots are measurement values.

- Only values with IN2/EXC coherence higher than 0.4 were used, otherwise the data were dropped.

- I tried to calculate the uncertainties of the measurements using the method in aLOG 10506, shown as error bars on the plots.

- Number of measurements taken:

  CHARD Pitch: 111

  CHARD Yaw: 44

  DHARD Pitch: 121

  DHARD Yaw: 33

We will take more measurements with same UGF values in the model and do more comparasion.