Reports until 15:13, Monday 18 August 2025
H1 SUS (SEI, SUS)
ivey.zhong@LIGO.ORG - posted 15:13, Monday 18 August 2025 (86430)
SR3 Pitch Estimator Fits

Last Tuesday, Oli took some pitch transfer functions for the pitch estimator (see LHO: 86203). 

The fits were added to the SVN and live inside '~/SusSVN/sus/trunk/HLTS/Common/FilterDesign/Estimator/Clean_fits_H1SR3_P-08-05.mat'. They are already calibrated to work on the filter banks for the estimator and can be installed using 'make_SR3_pitch_model.m', which is in the same folder.

Attached below are three images of the pitch estimator fits.

The first attachment shows the Suspoint P to M1 DAMP P fit. The zpk for this fit is:

    'zpk([-1.573-2.997i,-1.573+2.997i,-0.363-8.909i,-0.363+8.909i,-0.086-5.793i,-0.086+5.793i,-0.012-21.983i,-0.012+21.983i,0.391-14.449i,0.391+14.449i,1.12-1.455i,1.12+1.455i],[-0.421-1.748i,-0.421+1.748i,-0.193-10.021i,-0.193+10.021i,-0.145-13.141i,-0.145+13.141i,-0.115-4.125i,-0.115+4.125i,-0.093-4.667i,-0.093+4.667i,-0.061-21.579i,-0.061+21.579i],-0.001)'

The second attachment shows the M1 drive P to M1 DAMP P fit. The zpk for this fit is:

    'zpk([-0.226-4.432i,-0.226+4.432i,-0.008-5.377i,-0.008+5.377i,-0.001-20.571i,-0.001+20.571i],[-0.161-13.126i,-0.161+13.126i,-0.126-4.077i,-0.126+4.077i,-0.111-4.709i,-0.111+4.709i,-0.061-21.603i,-0.061+21.603i],75.096)'

The third attachment shows the Suspoint L to M1 DAMP P fit. We tried to fit the zero at 3 Hz as best as possible without compromising the rest of the fit. The zpk for this fit is:

    'zpk([-1.395-60.783i,-1.395+60.783i,-0.941-7.056i,-0.941+7.056i,0.685-18.736i,0.685+18.736i,0.887-6.92i,0.887+6.92i,0,0],[-0.198-10.004i,-0.198+10.004i,-0.141-13.133i,-0.141+13.133i,-0.095-4.093i,-0.095+4.093i,-0.083-4.646i,-0.083+4.646i,-0.06-21.579i,-0.06+21.579i],0)'

Images attached to this report