Typical arches are visible in the spectrograms of both B7 and B8_DC, they look uncorrelated between the two. The periodicity of arches looks around 10s.
At WE there is evidence of double arches, and also the scattered light pattern looks modulated by a 78.6Hz line .... which is not in ENV channels.
Scattered light glitches as seen by Omicron in B8.
In this spectrogram, arches are well resolved. The periodicity is ~1.4 s. The SNR is huge : several hundreds. As noted in the previous post, we see secondary arches and some echo around the ~80 Hz line. All channels processed by Omicron were checked. These arches are only seen in LSC_B8_6MHz_I with a much weaker intensity.
Similar arches were observed in the B7 signal.
No, there is no evidence of B7/B8 arches coupling to DARM.
The only coupling I identified is scattered light in LSC_B4_DC also seen in LSC_MICH_ERR.
