Telescopes in the Wind

I

An Experiment at W.M. Keck Observatory on the Summit of Mauna Kea, Hawaii

Isaac Crosson

UH Hilo Physicsand Astronomy

Department

Effects of the Wind on a Mountain-Top Observatory

Effects of the Wind on a Mountain-Top Observatory

Turbulence inside the dome deforms the

primary mirror and causes poor seeing conditions

Year

Evolution of Primary Mirror Diameter

MirrorSize

(Meters)

Year

Evolution of Primary Mirror Diameter

MirrorSize

(Meters)

0.9-Meter Lick Telescope

1887

Year

Evolution of Primary Mirror Diameter

MirrorSize

(Meters)

0.9-Meter Lick Telescope

188710-Meter

Keck Telescope1992

Year

Evolution of Primary Mirror Diameter

MirrorSize

(Meters)

0.9-Meter Lick Telescope

188710-Meter

Keck Telescope1992

Next-Generation Extremely Large Telescope

projects (ELTs)

Lick Observatory on Mount Hamilton was the first

Permanent Mountain-Top Observatory

Gemini North Telescope, Mauna Kea Hawaii

Gemini North Telescope, Mauna Kea Hawaii

Precision Instruments and Controls

Gemini North Telescope, Mauna Kea Hawaii

Ventilation Gates

Extremely Large Telescope Projects

Extremely Large Telescope Projects

Primary Mirror Diameter 20-100 meters

Thirty Meter Telescope (TMT)

Location to be determined

Projected to be complete by 2020

Predicting the Wind Effect

Computer Simulation (CFD)

Secondary Mirror

Predicting the Wind Effect

Computer Simulations (CFD)

Wind Tunnel Experiments

Predicting the Wind Effect

Computer Simulations

(CFD)

Wind Tunnel Experiments

Predicting the Wind Effect

Computer Simulations

(CFD)

Wind Tunnel Experiments

Current Generation

Large Telescopes

Golden Opportunity at the Commissioning of Gemini South

Predicting the Wind Effect

Computer Simulations

(CFD)

Wind Tunnel Experiments

Current Generation

Large Telescopes

Current Experiments at Keck II and Gemini North

Details of the Keck II Experiment

Details of the Keck II Experiment

Mauna Kea Weather Center Archives

Details of the Keck II Experiment

Mauna Kea Weather Center Archives

Drive Control System(DCS) Log Files

Data Records from the TMT Configuration

A Directory Containing Files from a single night

of Keck II Operations

Nightly Files Contain Column Data Headed by Engineering Codewords

Decided to use an Event-Based Log File

My Script synchronizes Keck data with TMT data

Wind disturbance is a primary concern for next-generation extremely large telescope projects.

Experiments at existing large telescopes are best, but these are costly and difficult.

Wind data collected at Keck is most useful when it is cross-referenced with telescope activity logs, and external weather data.

Thanks and Acknowledgements

Thank you to my mentor Chris Neyman, lead observing assistant Barbara Schaefer, software guru Shui Kwok, and everyone else who helped me at

Keck Observatory!

Thank you to Sarah Anderson, David Le Mignant, Scott Seagroves, Hilary O'bryan, my fellow interns, and everyone on the CFAO Big Island Akamai team!

Thank you to George Angeli and the other wind team engineers at the TMT Project!

The Akamai Observatory Internship program is funded by the Center For Adaptive Optics, a National Science Foundation

Science and Technology Center (STC), AST-9876783