NGAO Alignment, Calibration, and Diagnostics mini-review
Questions and comments from Jim Lyke
KAON 719
Sec. 2.4 Alignment Requirements
Focal plane alignment (x,y), 4th bullet: Does DAVINCI team know about instrument position requirement to 0.2 mm or a possible alignable coronographic field stop and has it been designed?
Pupil plane alignment (x,y), 1st bullet: Does DAVINCI team know about this 75 micron requirement?
Tilt (theta x, theta y), 2nd bullet: Would these off-axis aberations add to the WF error budget? Is there a rough calculation?
General question: Have requirements for xyz stage for the kinematic instrument mounts been fleshed out? If not, please consider discussing with DAVINCI team.
Focal plane alignment (x,y), 2nd bullet: Is this in the f/15 beam? If so, <0.2 arcseconds is <0.14 mm, which seems tight. What is the range of the fast TT mirrors? If 5", seems this could be relaxed by a factor of 2 without losing much dynamic range and still be smaller than median seeing.
Focal plane alignment (z): 2 mm is not critical if and only if the LGS WFS focus stage is not near a limit or end of travel.
Calibration Unit
Implies an on-axis point source at NGS focus, are there 3 off-axis point sources that can be fed into the LOWFS? Will these be available to use simultaneously with the LGS sources to simulate observing? This is a vital testing mode.
In addition to focus range to accomodate an ADC, phase retrieval (image sharpening) requires +/- 4 mm of defocus at f/15, psuedo pupil requires +/- 10 mm defocus @f/15
Is there a Na layer at 150 km? Can the 80 km conjugate track to 90 km?
Sec. 3.7 LOWFS to AO Relay Alignment
Does aligning the LOWFS via the TWFS align all three LOWFS or just the one with the TWFS?
Sec 3.10 DAVINCI Science Instrument to AO Bench Alignment
Do you expect DAVINCI to have xyz adjustments for its kinematic mounts?
Why is there no pupil imaging mode for DAVINCI? It has proved very useful for K2AO
Sec 3.11 AO Bench Warm Enclosure Testing
What is the mechanism to align both science instrument detectors and the coronographic focal plane mask?
Sec 4.2 Summit Alignment Preparations
Who is responsible for deconstructing/decommissioning K2AO and NIRC2?
What is the proposed schedule?
What is the design load of K2 LNAS? How does it compare to the likely weight of the new AO enclosure, bench, and DAVINCI?
Are the design mods to K2 LNAS envisioned to be major?