Derek Davis, Adrian Helmling-Cornell, Brennan Hughey, Jenne Driggers

Summary: Any increase in frequency noise at Hanford is worse than the current impact of whistles

Whistles currently are one of the most problematic noise sources for burst searches, and hence are a high priority to mitigate. Approximately 1% of data is corrupted by whistle glitches, although they can be easily identified in general. 

At Livingston, the rate of whistles dramatically decreased after swapping out the VCO. We investigated whether the same swap would be beneficial here at Hanford. The main trade off is a significant increase in frequency noise. 

The overall impact of a factor of 10x increase in frequency noise can be seen in attachment 1. Such an increase in frequency noise would drop the range down to ~65 Mpc. Even a more modest increase of 3x would lower the range to ~105 Mpc. As this decrease is much more significant than the current impact of the whistles, we conclude that any whistle fix must not significantly increase frequency noise for it to be beneficial.