Noise Subtraction subgroup

Pre-meeting
- Date/Time: Tuesday, November 5th, 2024, 1600-1800 JST (0700-0900 UTC)
- Connection Info.: Zoom1
- Agenda
  - Brief Overview of Noise Subtraction Activities
    - Application to GW experiments/analysis
      - What can be accomplished? How effective is it in improving sensitivity/analysis etc.?
    - Activities at KAGRA
      - who, what, features, current status, future plan?
        DeepClean
        ICA (Independent Component Analysis)
        Other ongoing initiatives?
        Has each research unit or search pipeline been developing noise subtraction optimized for their specific needs?
    - Other efforts within LV(K)
      - NonSENS (NON-Stationary Estimation of Noise Subtraction)
        NonSENS codebase: https://git.ligo.org/gabriele-vajente/nonsens/-/tree/master/nonsens
        Running online (in the front-end) at LHO/LLO
        Front-end implementations:
        LHO https://git.ligo.org/noisecleaning_o4/frontend-nonsens/lho-online-cleaning
        LLO https://git.ligo.org/noisecleaning_o4/frontend-nonsens/llo-online-cleaning
        Estimates the optimal noise subtraction based on witnesses for the noise and witnesses for modulation of the noise coupling
        Witness channel can be individual channels (linear subtraction), or product of two channels (bilinear subtraction)
        The output channel is available in the control room, for use with commissioning, and is the same channel that analysis pipelines will use.
      - ...
  - Scope of the group to be established
    - Organization?
      - Chia-Jui Chou from Natl. Yang Ming Chiao Tung U. will lead the group as the chief.
      - Will it encompass all noise subtraction-related activities at KAGRA?
      - Will it focus specifically on areas that contribute to the commissioning timeline, i.e., low- or middle-latency?
    - Roles/Goals for each phase
      - during the commissioning period prior to participating in O4b observation
      - during the O4b observation
      - for future phases O5/O6
    - How collaborate with on-site commissioners/IFO experts?
      - e.g.,
        Commissioners may request specific noise subtraction, such as subtracting noise in channel-A using auxiliary channel-B?
        Commissioners may manage a safe channel list?
        ...
      - What considerations should guide us as we progress? How should we work with the team?
- NOTE: The following terms mean completely different things. Please use them correctly when discussing. -- safe channel, witness channel, auxiliary channel, ...