1. 1 2009 LO WFS Summit 6/19/2015Richard Dekany A Joint Meeting of the NGAO, IRIS, and K1 LO WFS Teams 12/15/2009

2. Agenda 8.30am-8.45am WFS requirement comparisons RGD (15 mins) 8.45am-9.45am NGAO WFS (Kent/Alex) + discussion 9.45am-10.45am TMT IRIS OIWFS + discussion (David L.) 10.45am - 11.00am Break 11.15am-12.15pm Keck IR TT + discussion (Roger) 12.15pm-12.45pm Detector update + discussion (Roger) 12.45pm-1pm Summing up

3. 3 LO WFS Requirements Comparison 6/19/2015Richard Dekany 2009 LO WFS Summit 12/15/2009

4. AO system comparisons (All # TBC during meeting) Keck 1NGAONFIRAOS LGS asterismSingle, on-axis Fixed 3+1 tetrad on 10” radius and Patrolling 3 within 60” radius Fixed 5+1 on 30” radius Laser power30 W of LMCT format 4 x 12.5 W SOR format and 3 x 8.6 W SOR format 6 x 25 W SOR format First Light Science Instrument(s)OSIRIS, NIR IFS and imagerNGAO NIR IFS and imager IRIS, NIR IFS and imager IRMS, NIR MOS TT NGS sharpening strategySCAOMOAOMCAO First light (if funded)2013-14 for IR TT>= 2015>= 2018

5. LO WFS Input Plate Scales Keck 1 arcsec = 0.727 mm1 mm = 1.38 arcsec 1 mas = 0.727  m1  m = 1.38 mas TMT 1 arcsec = 2.18 mm1 mm = 4.29 arcsec 1 mas = 2.18  m1  m = 4.29 mas

6. Driving Requirements Keck 1NGAOIRIS Volume constraintTight; complex …containable w/in… 2m diameter and 750 mm height [REQ-3-IRISOIWFS-0010] (BFD is actually 780 mm) Pixel IFoV~12 mas …pixel IFoV shall be 4.297+-0.200 mas [REQ-3-IRISOIWFS-0220] Detector readout (per chip) Redefinable multiple RoI; Full-field ACQ mode Redefinable single RoI; Full-field ACQ mode Rapidly redefinable single RoI; Full-field ACQ mode ADCNo requirement Each WFS subass’ly shall include a separate ADC [REQ-3-IRISOIWFS-0170] Power dissipationNo requirement …< 2 W into NFIRAOS chamber… (0.5 W goal) [REQ-3-IRISOIWFS-0090] Patrol range per OSM channel None Ø120” = 87 mm [FR-159] …enough to meet NFIRAOS sky coverage… [REQ-3-IRISOIWFS-0280] OSM motion accuracy/precision None TBD [FR-177] (typ. 2  m precision?) …absolute accuracy…< 2 mas RMS anywhere in…patrol range…[e.g. < 4.6  m] [REQ-3-IRISOIWFS-0610] Science FoV (to not obscure) No requirement (restricted J-H FoR) ø15 mm = 20” ø29 mm = 40” (goal) [FR-41] Ø58 mm = 25” [REQ-3-IRISOIWFS-0240] (changing as of 12/15/09)

7. OIWFS comparisons Keck 1NGAOIRIS Number / Type of NGS WFS 1 TT (TTF goal)2 TT + 1 TTFA (dedicated)3 TT / TTFA (selectable) Object Selection Mechanism NoneTheta-phi probe armsR-theta probe arms Active mirrorsNone32 x 32 MEMS DM None (accessible pupil) LO WFS gravity environment Fixed at Nasmyth OSM patrols vertical plane at Nasmyth Patrols horizontal plane at Nasmyth; rotates LO WFS acquisitionFull FoR imaging Ø 5 arcsec OSM FoV w/ aux. visible ACQ camera available Ø 4.4 arcsec OSM FoV w/ aux. IR ACQ camera available Spectral band K (full FoR) or J through H (> 35” off-axis) J through H

8. 8 LO WFS Summit Wrap-Up 6/19/2015Richard Dekany 2009 LO WFS Summit 12/15/2009

9. Areas of potential common interest Detectors – HxRG characterization Other interests: HgCdTe e-APD (256 x 320, ~60-80% QE coming)? – Linux controller implementation – Pixel sampling ( /2D; arguments for J vs. H ?) Filters / Coatings – J through H vs. J + H (w/ possible K-blocking) ADC designs? Dewar thermal designs / cooling systems (Smith / Vasisht) Small OSM focus motions? – Collimator squiggle stage vs. sensor plunger stage Dithering strategies? – NGAO needs to tackle this in next couple months Time studies for acquisition timeline (Bouchez) – Requirement of 120 seconds each (after slew) Component cost estimates? Calibration units – Positional accuracy of probe arms (e.g. I&T position calibration using aux. equipment) – AO relay distortions (e.g. using a fiducial pinhold grid mask for IRIS)