Telecon 20180214

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

Notes by : Qi

• 2.5 day Workshop: May 1,2,3; in Minneapolis.
• Telescope and instrument I+T (Tomo, Bill J)
  • Telescope I+T (.pdf) (Tomo)
  • Receiver, Bill Jones (.pdf)
• Attitude control requirements (Jacques) (.pdf)
  • Images from Kris
  • | (.png) | (.png) | (.png) |
• Focal Plane updates (Karl) Focal plane slides (.pdf)

• 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.