Andrei, Sheila, Naoki

We've observed that the reduction of the observable range is accompanied by the presence of "whistles", high-magnitude frequency-modulated signals in the spectrum in SQZ FC WFC.

Sheila created several plot overlays to demonstrate this dependence. Specifically, we selected the Lock : Range : DMT-SNSL_EFFECTIVE_RANGE_MPC and SQZ : Subsystems : SQZ FC WFC plots and overlaid them to highlight the relation between them.

• overlayjune2.png shows no “whistles,” and the range does not undergo any significant decreases.
• overlayMay18.png, overlayMay21.png and overlaymay30.png datasets exhibit the presence if "whistles" and a corresponding range decrease.
• overlayMay22.png, overlayMay23.png datasets dont have the visible "whistles", but the 10-20 Hz low-frequency noise band increases during the range decrease.

DARM_comparison.png plot contains the 18th of May 2024 DARM during the “whistle” and during its absence. ≈0.5 dB difference is observed.