Used double coincident lockloss time this morning to installl new Pcal inverse actuation filter at X-end. I took a transfer function between RxPD and EXC with Inverse actuation filter engaged. The result is attached below. The plot shows a good agreement at lower frequencies (upto few hundred Hz) and is about 2 percent off in magnitude and 7 degress off in phase at a KHz. This is expected because the foton implemetation of filter is little diffrent from its intended response.
We will test it with CBC waveform and detchar safety injection at the next opportunity.
The script used to make this plot is committed to SVN:
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/O1/H1/Scripts/INVACT_PCAL/analyze_invactpcal.m
Procedure to perfrom Hardware injection through Pcal:
1. Turn of the pcal excitation.
2. There are two filters in H1:CAL-PCALX_SWEPT_SINE filter bank. Turn on both F1 and F2 if your injection is in units of Strain. Turn on F1 only if it is in units of meter.
3. Perform an injection.
4. Turn off the filters after you are done
5. Turn back the pcal lines on and make sure the SDF monitor for CALEX is all clear.
Looking at the checked in analyze_invactpcal.m, I noticed that you correct not only for the anti-aliasing analog and digital filters in the readback path (which you do need to get to get meters as read by the PCAL), but you also correct the plot for the anti-imaging analog and digital filters. This implies that the actual induced motion of the mass is off by the anti-imaging analog and digital filters as you had to apply this correction in post-processing. So the plot you attached tells us how good of a match we have if we pre-warp the injections by the known anti-imaging filters or take them into account in post-processing when looking for them in search pipelines. In the case where that is not done, then I believe the attached RxPD_over_EXC_no_IOP_compensation.jpg is closer to how the magnitude and phase will be. All I have done to the analyze_invactpcal.m script is removed the IOP upsampling filter , "par.A.antiimaging.digital.response.ssd" in the calculation of RX_over_EXC_corrected variable. The plot is still correcting for the analog anti-imaging (as its mostly delay like) and the zero order hold (again delay), which generally just creates a shift in the start time of the injection.
