====== Telecon 20180214 ======

Attending: Brian, Amy, Roger, Al, Kris, Julian, Jacques, Karl, Qi

Notes by : Qi \\

=== Agenda===

  * 2.5 day Workshop: May 1,2,3; in Minneapolis. 
  * Telescope and instrument I+T (Tomo, Bill J)
    * {{::telescopei_t_v002_20171212_s.pdf|Telescope I+T}} (Tomo)
    * {{::plancki_t_jones_20171212.pdf|Receiver, Bill Jones}}
  * [[https://zzz.physics.umn.edu/ipsig/_media/systematicswg/telecons/2018-02-14/pointing.pdf|Attitude control requirements (Jacques)]]
    * Images from Kris
    * | {{::m000.png?100|m000.png}} | {{::m000ge.png?100|m000ge.png}} | {{::m000gm.png?100|m000gm.png}} |
  * Focal Plane updates (Karl) {{::focalplane_update_20180214.pdf|Focal plane slides}}

=== Notes ===

  * Workshop
    * Working on program, plan to release in next few days
    * about: science, report, white paper if there is, data complement other data sets

  * Spacecraft (Amy)
    * we will need space craft bus, everything around the instrument
    * biggest challenge is point the instrument, spinning ,precession
    * mission TeamX
      * orbit (shape, size of orbit, sun & moon), ground processing
      * industry parter, preliminary design;
      * requirement for the craft, pointing stability & accuracy, mass, power we need
      * a week after TeamX

  * Attitude control requirements (Jacques)
    * sampling requirement
      *  For CORE, 1/4th, constrained by scan strategy
      * for each position on the sky, we want to compare compare data, important for systematics
      * The requirement of sampling will translate to the requirement of altitude
        * Uncertainty on the position of spin axis, from one scan to other, translated to difference between two scans.
      * good control helps reduce gaps as much as we can
      * 
    *  Cross-scan sampling per precession
      * Currently, T_prec = 10 hours, T_spin = 1 min, which lead to theta = 3'
      * 3' is good for 100 GHz, but not above; we can change T_spin or T_precession
      * Kris does not think changing T_precession / T_ spin can solve the problem globally. Very long precession, penalty is pile up enormously at poles.
      * we are assuming engineering achieving nominal, by 1 arcmin in 3 sigma error per spin.
 
  * Point reconstruction
    * alignment of instrument FOV with reference of spacecraft. change should not be faster than calibration
    * Jacques: we need to do simulation to get final number for point reconstruction
    * Shaul: 1’’ will be driven by systematics. We will see if 1’’ is reasonable given r value.
    * Amy: too loose, worse systematics; too tight, expensive to engineering.