LBNL-2016: Time-Ordered Data Processing

Time-Ordered Data Processing Birds-of-a-Feather Session: Wednesday, March 9, 9 AM

Attending: Julian Borrill, Tom Crawford, Ted Kisner, Kris Gorski, Graca Rocha, Clem Pryke, Nick Harrington, Jesse Treu, Kyle Story, Nathan Whitehorn, Olivier Perdereau, Reijo Keskitalo

Notes

Discussion of TOD scanning simulations

• Scanning with full 4-pi beam: do we really get the 4-pi beam at high fidelity?
  • at some level, not the data folks' problem.
• Are we really going to simulate full TODs, including data that we will eventually cut in the real TOD?
  • yes, at least to test automated data cuts.
  • who is going to take on the task of creating this model?
  • we pretty much know how to do it now, unless the fundamental detector and/or readout architecture changes.
• Do we need to simulate TES & electronics response?
  • Not a high priority. Assume detectors/electronics with funky response will not pass CD.
• RFI pickup?
  • Impossible to implement in sims without model of pickup.
• Time-dependent focal plane / optics distortion?
  • Real-world examples to go on from ACT & PB
• We need scan strategy to be defined to do sims.
  • Is anyone considering using anything but azimuth scans as fast and wide as you can go?

Digression into computing plan

• Are we really going to use grid computing (rather than parallel processing on large clusters)?
  • Certainly not for anything for which we have to send around real TOD. (I.e., just for sims.)
• What about data management / delivery from sites?
  • Pole bandwidth barely accommodates SPT-3G and will be unlikely to increase enough to handle S4. Similar issues exist in Atacama.

Return to TOD sims

• Will there be half-wave plates on S4?
  • Can't rule it out. How do you make a model of non-ideality for a HWP?
• Are we aiming to have a perfect set of TOD sims by summer or 10 years from now?
  • There will be a profile of what we can simulate. Could in theory have some level of TOD sims by summer.
• What about atmosphere?
  • Moving slab prototypes exist.
• Loudly stated that TOD sims will not be used in the 3-month timescale forecasting.
  • OK, but is there something we can do on the next timescale (~6 months)
  • At least agree on common inputs & data formats.
    • That's coming up soon.

Time to Pixel Domain

• Are preprocessing steps included in instrument

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Word of the day: Exciting

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Gotcha scorecard

TIme	Deliverer	Receiver
9:59	Ted	Nathan