Precision Calibration Workshop
July 9-11, McGill University
Exquisite calibration is needed to successfully separate the faint cosmological 21 cm signal from bright foregrounds. There has been enormous development in precision calibration techniques, and we have a much better understanding of both the state-of-the-art and the fundamental limitations of many calibration approaches. We feel this is an ideal time to gather the expert calibration community to share what we have learned, discuss some of the exciting new techniques, and foster new collaborations.
The workshop is organized around a set of discussion sessions to foster discussion and collaboration. For each session we will recruit a couple of experts to give a brief introduction/overview, followed by a panel discussion or a guided group discussion.
Below we have the draft session itinerary (we will be recruiting folks for overviews and panels), and the participant list. Please click here for logistics (hotels, maps, parking, etc.).
Session Schedule (draft)
Monday and Friday folks are encouraged to visit the Institute and hold side meetings. Let us know if you need space.
Tuesday
8:30 rooms open, coffee and nibbles. Sessions will be in the Boardroom and Bell room located on the ground floor of the Ernest Rutherford building, 3600 University Street.
9:00 Welcome and Introductions
Who are you, where are you, what do you work on, what are you particularly interested in right now?
chairs: Matt Dobbs & Miguel Morales
Instrument & calibration overviews
~15 minute overviews of the key instrument characteristics and associated calibration efforts. Goal is to familiarize everyone with the current status of major calibration efforts, including successes and challenges.
Seth Siegel, Cathryn Trott, Danny Jacobs
Coffee Break
10:45 Beam measurements & direction-dependent calibration
Mini-overviews by panel members (2-3 slides), followed by panel discussion
Key questions: Joys & sorrows of drones/holography/pulsars/sky model/polarization/satellites. Problem of polarization.
Gary Hinshaw, Danny Jacobs, Cathryn Trott; chair Laura Newburgh
Lunch
1:30 Bandpass measurements & direction-independent calibration
Mini-overviews by panel members (2-3 slides), followed by panel discussion
Key questions: What precision is necessary? What determines this? Sky calibration (either per antenna or for degenerate parameters), artificial bandpass calibration, autocorrelation.
Nichole Barry, Seth Siegel, Robert Pascua, Bryna Hazelton; chair Jonathan Pober
Coffee Break
3:30 Emerging calibration techniques
Short presentations of new calibration approaches: describe their approach, current status, pros & cons in ~8 minutes.
Followed by panel/group discussion.
Jon Sievers, Laura Newburgh, Ruby Bryne, Peter Sims, Miguel Morales; chair Cathryn Trott
Cinq à Sept (5-7)
Wine, tapas & live Jazz from local music high school (bring $5-$10 to pass the hat for the musicians) hosted by TSI.
Wednesday
9:00 Foreground-instrument coupling & subtraction techniques
Mini-overviews by panel members (2-3 slides), followed by panel discussion
Key questions: most problematic foreground sources (compact, diffuse, polarized, etc.), instrument coupling issues (e.g. galaxy in antenna sidelobes), and methods for subtracting, mitigating, and inverting the foreground emission.
Arnab Chakraborty, Simon Foreman, Adrian Liu; chair Miguel Morales
Coffee Break
10:45 RFI excision, spectrum evolution, and gap in-filling
Mini-overviews by panel members (2-3 slides), followed by panel discussion
Key questions: best methods for detecting RFI, RFI below the detection threshold, new and emerging sources of RFI, and techniques for mitigating foreground bleed due to RFI-sourced gaps in time & frequency.
Michael Wilensky, Dallas Wulf, Jonathan Pober; chair Bryna Hazelton
Lunch
1:30 Mutual coupling, and the joys and sorrows of simulating antenna beams
Mini-overviews by panel members (2-3 slides), followed by panel discussion
Key questions: predicted vs. as-built antenna beams, antenna coupling and reflections, identifying antenna issues & coupling
Robert Pascua, Gary Hinshaw; chair Matt Dobbs
Coffee Break
3:30 Structured discussion breakouts
Gather what people find interesting to discuss/work on next, identify 3-5 of topics and have folks interested in those topics gather at a table/room and discuss; last 20 min regather and report back.
chair Miguel Morales
Thursday
9:00 Quantifying & marginalizing over model errors & model mismatches
Error is noise or systematics on a model parameter; model mismatch is when model parameters don’t match reality even in absence of noise & systematics. These kinds of errors appear in sky & antenna terms necessary for precision calibration.
Mini-overviews by panel members (2-3 slides), followed by panel discussion
Key questions: How do we conceptualize, measure, and mitigate these kinds of errors in our calibrations? How do we explore in simulation and/or analytically?
Steven Murray, Peter Sims, Simon Foreman; chair Adrian Liu
Coffee Break
10:45 Emerging topics
TBA
Lunch
1:30 How am I voting with my feet? What do you see as the next big direction to go?
Structured group discussion
chairs: Matt Dobbs & Miguel Morales
3:30 Workshop end
Space and time for folks to continue collaborating if desired.
Participants
Nichole Barry
Libby Berkhout
Ruby Byrne
Arnab Chakraborty
Jade Ducharme
Matt Dobbs
Simon Foreman
Bryna Hazelton
Gary Hinshaw
Danny Jacobs
Adrian Liu
Kyle Miller
Miguel Morales
Steven Murray
Laura Newburgh
Robert Pascua
Ue-li Penn
Jonathan Pober
Seth Siegel
Jon Sievers
Peter Sims
Saurabh Singh
Emilie Storer
Cathryn Trott
Dallas Wulf
Michael Wilensky