Closed Loop Performance

Laird Close and MagAO team

SAC review

Requirement 1: The MagAO system high level VisAO Science

Goal (bright stars)

• To obtain Strelhs of 10% or better in median seeing (0.7) on-axis at 0.8 um.

• This is equivalent to 190 nm rms residual wavefront error.

Results

Results

Achieved “on-sky” 122 nm rms wavefront error at 800 Hz --- much better than 190nm goal

Comparing to Simulations

ERROR BUDGET

Closing the Loop at 1000 Hz

At 1000 Hz closed loop we can achieve 65 nm rms error in tower ~95nm “on-sky”.NOTE that this is a linear stretch. This is much better than the 190 nm rms

requirement.

See the movie!

• http://www.youtube.com/watch?v=arjTorNtnCc&context=C4a1ba7aADvjVQa1PpcFNung4fzsYWr1SBl5fXtvLidUbAL4M9VSc=

• Also see a video of how we close the loop here:

• http://www.youtube.com/watch?v=wSiFoG8qgKI&context=C4a1917aADvjVQa1PpcFNung4fzsYWrw_ocFrcNJysPjatEvtUZbY=

Comparing to Simulations

Comparing to Simulations

68% “on-sky”

Clio2

• Clio2 can do excellent science with higher wavefront errors. Hence there is a need for Faint Star Performance as well to increase sky-coverage.

Goal 2: The MagAO system high level Clio2 Science Goal (faint stars)

• To obtain Strelhs of 85% or better in median seeing (0.7”) on-axis at 3.8 um (L’) for a R=13 guide star. (or SR>96% at 8um on MIRAC4).

• This is equivalent to 250 nm rms residual wavefront error.

Performance on Faint stars

Here we have in z’ a Strehl of 13% or 210 nm rms error. This would be about 9.5% “on-sky” or 221 nm rms. This is better than the faint star goal of 250 nm rms

Summary:

• Science requirement of <190 nm error for bright guide stars in median seeing is met, and improved on, by a significant margin with <95-122 nm rms achieved (800-1000 Hz, 400 modes) (by almost 2x lower in rms wavefront error).

• Science requirement of <250 nm rms error for faint (R=13) guide stars is met and improved on with typically ~221 nm rms (200 Hz, 150 modes) is achieved.