https://logbook.virgo-gw.eu/virgo/?r=39525 CEB
https://logbook.virgo-gw.eu/virgo/?r=38567 NEB
https://logbook.virgo-gw.eu/virgo/?r=38534 WEB
The projection in NEB is probably under-estimated because of a strange coupling of the injected lines seen by the magnetic probes (figure 2). The other tranfer functions between injected lines and magnetic noise level seen by the probes, are nearly flat with frequency (figure 3-4).
Figure 5-6-7 are the transfer functions between Hrec and magnetic probes.
Figure 8 is the total contribution of magnetic noise from all the buildings, namely the sum in quadrature of the 3 buildings projections. This curve is compared with the past simulations of the magnetic coupling with AdV payloads and they are quite compatible. For the time beeing magnetic noise is nearly 2 odm lower than the best sensitivity of O2, but in the future a mitigation plan would become crucial.
Eventually figure 9 is another magnetic noise projection, done with a different approch: sqrt of a long-time coherence (10 hours in Aug 23) between DARM and magnetometers, multiplied by DARM spectrum. In this case the magnetic spectrum seen by the probes is taken as the injected magnetic field. Still to be undestood if this method works properly and if the increasing trend at high frequencies is real or it's just an artifact.
Further reference can be found in the published article https://iopscience.iop.org/article/10.1088/1361-6382/ab4974/meta
