I analyzed the OMC acoustic injection data:

2025/04/03 05:31:00 - 05:51:00 Speaker injection OMC area
Excitation : K1:PEM-EXCITATION_SR3_RACK_6_EXC
50 - 900 Hz white noise injection 1,500 cnt

• Fig.1: Spectrograms for the strain, the microphone, the geophone, the OMC error signal, and the square of the OMC error signal
• Fig.2: ASDs of these channels, for the reference and the injected time
• Fig.3: Microphone -> Geophone coupling and projection
• Fig.4: Microphone -> OMC error coupling and projection
• Fig.5: Geophone -> OMC error coupling and projection

Because any significant excess was found in the OMC error signal limited by its sensing noise, a noise projection on the strain was impossible.