====== Telecon 20171107 ======

Attending: Brian, Julian, Al, Roger, Jeff, Jacques, Jon G.

__Agenda:__ 

  * Preparations for TeamX in Dec. 
    * Finalizing optics with/out deployables + focal system (Karl, Qi)
      * {{::1.2m_vs_openv3d_20171102.pdf|Comparing 1.2 m crossed and 1.4 m open}}
    * Telescope: material, alignment, testing
    * Cooling 
  * Mission
    * Scan angles (Gorski)
    * TM data rates [as a function of smallest beam size (??)]
  * Systematics + noise
    * Combining our telecons with systematics group 
      * impact of low frequency noise
      * Sidelobes (Grasp / Analytical calculation)
      * Gain stability
      * pol angle calibration
     

=== Notes ===

Prep for Team-X meeting in mid-Dec.  They will cover telescope + focal plane + Cooling = instrument
  - Optics of 1.2m vs 1.4m.  1.4m open has better resolution and sensitivity.
    - No glaring issues with open, even though it is less traditional.
    - Brian: Does baffle create sidelobes?
      - Shaul: Goal is to do a basic GRASP calculation to figure this out. In contact with Brad Johnson
    - Karl will calculate sensitivity of crossed at 4K. Maybe something to pursue.
  - Should we go to Team-X with multiple options?
    - Al: They tend to split their time evenly amongst options they are given.  Would need to make clear what our focus is if we bring multiple options.  Prefer taking just 1 workable option.  It's time to finish with optics and move focus to other issues which need work.
      - Shaul: Our case is 1 basic framework with options being changes on top of this.
      - Al: Team-X can do this if the scope is made clear in pre-session.  However may not be most effecient use of Team-X time/expertise.
  - Gathering telescope quotes:
    - Brain, JPL, and Shaul.
    - Components are fraction of cost.  Majority of cost is testing.
      - Al: WMAP testing was cold photograms, warm beams, accounted for cooling deformation with models
      - Jacques: Planck testing was sidelobes warm, deformation and alignment as mirror cooled, no end-to-end cold test with flight system.
        - CORE estimate, very unofficial, was $10-20 million
  - Cooling:
    - Chris Payne working on strategy
    - continuous ADR cost from Goddard slow to come in.  Working on this.
    - Possible single shot ADR from Europe. planned for Athena mission.
      - Jacques: Same group is developing continuous ADR.  Probably low TRL currently.  Jacques willing to connect people if needed. (not needed currently)
    - Roger: Will send around BLISS ADR system. Was a bench test system at JPL.

Skip Mission discussion for now, deadline in March although work needs to begin.

Systematics
  - What do we need for 1/f? Sidelobes? Gain stability? pol angle calibration?  And how to simulate this.
  - Sidelobes: Estimate in GRASP via Brad J.
    - Jacques: This job is very large and approximations are often done.
    - Shaul: Plan is to do a course model to get representative levels.
  - Julian: Simulation pipelines exist to take scan + sidelobes, produce maps, and estimate systematic errors in parameters.
    - need proper inputs
    - simulation of mitigation of sidelobes is harder.  Need a way to estimate your sidelobes and your mitigation method separately, then combine in simulation.
    - typically simulate each systematic separately, then do 1 sim with all systematics to see overall effects.
      - Shaul: this can get infinitely complex. We'll focus on the 3 issues highlited by systematics group first.
    - All these are doable, suggestion: Do 4-5 locations on focal plane.
      - Jacques: do 4 detectors simultaneously so you get 1 Q and 1 U measurement.