1. 1 Time-Domain Calibration Update Xavier Siemens, Mike Landry, Gaby Gonzalez, Brian O’Reilly, Martin Hewitson, Bruce Allen, Jolien Creighton

2. 2 A CoCo DoDo +-+-  AS_Q DARM_ERR = DARM_CTRL_EXC = m DARM_CTRL = ++++ S4 Feedback loop Control signal External signal Residual signal

3. 3 S4 signal processing pipeline LP FIR LP FIR HP FIR ++++ - Reference functions digitised are for v1 calibration. - Factors  are computed at 1Hz. - All science data is available in the form of 256s frames (sometimes shorter at the end of a science segment). - Systematic errors at most ~1% in amplitude and ~1 o in phase, between 30Hz and 3000Hz - The calibration lines, and anything else added to DARM_CTRL, approximately cancel. This includes ringing due to calibration line dropouts.

4. 4 - When final S4 calibration is out we’ll make the h(t) for it. - For S4, will change the pipeline to generate the control signal from DARM_ERR (not DARM_CTRL). This is due to some artefacts found in DARM_CTRL (see M. Landry’s talk coming up soon). Calibration accuracy at low frequencies (~30Hz) will most likely be degraded (a few percent in magnitude, a few degrees in phase). - For S5 will be running online under onasys (as during S4); hopefully the problem with DARM_CTRL will be fixed and we can use it to make h(t). Plans and Prospects

5. 5 Coming up: h(t) experimentation - Talks by: - Mike Landry for pulg - Stochastic group - Igor Yakushin for the burst group - Saikat Ray Majumder also for the burst group Many thanks to them also to Laura Cadonati and Philip Charlton!