J. Kissel

After this Tuesday's maintenance day, when I installed the H1 SUS PR3 pitch and yaw estimators (LHO:86578), I'd thought I'd turned them OFF. I'd accidentally left the pitch estimator ON. Whoops! I've turned them OFF this morning -- if only to get some data with *just* the improved SR3 estimators (i.e. that the SR3 pitch estimator now includes longitudinal sus point to M1 contributions; see LHO:86567 and LHO:86589).

The first nominal low noise and subsequent observation segment with SR3 P & Y (P with improved Sus Point L to M1 P contribution) and PR3 P (also with Sus Point L to M1 P contribution includes) was right after maintenance,
    2025-08-26 21:16 UTC,
but really it had been on from 2025-08-26 17:44 UTC.

I turned the PR3 pitch estimator off by 2025-08-28 15:15 UTC.

For reference, assuming everything upstream of the switch is on and functional, you can look at the "use estimator or use OSEM" switch status to check if the estimators are on. The current status is
    H1:SUS-PR3_M1_EST_P_SWITCH_NEXT_CHAN  2.0
    H1:SUS-PR3_M1_EST_Y_SWITCH_NEXT_CHAN  2.0
    H1:SUS-SR3_M1_EST_P_SWITCH_NEXT_CHAN  3.0
    H1:SUS-SR3_M1_EST_Y_SWITCH_NEXT_CHAN  3.0
i.e. (as stated above) the PR3 estimators are OFF = NEXT_CHAN = 2, and the SR3 estimators are ON = NEXT_CHAN = 3.

At superficial glance, i.e. "we've been in nominal low noise observing since they've been on," the IFO doesn't seem to mind AT ALL. And we have a data point of 1.0 that says that we can make it through initial alignment and lock acquisition with it on as well.
We'll post some more quantitative metrics in a bit.