| A CSO Submillimeter Active Optics System - DSOS |
| CSO Technical Brief | |
| Oct. 4, 2007 | |
| Melanie Leong | |
| Caltech Submillimeter Observatory |
| DSOS Presentation Agenda |
| Specifications & Prototyping | |
| The DSOS System | |
| DSOS Performance | |
| Improvements to the DSOS | |
| SHARC2 Observations | |
| Conclusion |
| DSOS - RMS Surface Deviations, 1998 |
| DSOS Specification & Prototyping |
| Desired Performance Specifications | ||
| +/- 25 micron length change for most of the dish | ||
| Reduce RMS surface error from 25 micron RMS to 15 micron RMS | ||
| Improve aperture efficiency by a factor of 2, integration time by a factor of 4 | ||
| Single Channel Prototypes & Heat Transfer Studies | ||
| Determined +/- 25 micron feasibility | ||
| Heated Standoff interactions with Structure | ||
| 3 Channel Controller & Driver Prototype | ||
| Established system architecture, parts & material | ||
| Demonstrated desired length change could be achieved | ||
| 99 Channel Dish Surface Optimization System requested to build in January 2001 | ||
| DSOS System Diagram |
| DSOS Simplified Block Diagram |
| DSOS Standoff Assembly |
| DSOS Dish Wiring & Plumbing |
| DSOS System Racks |
| DSOS 99 Channel Controller Unit |
| DSOS 99 Channel Controller Unit (cont.) |
| DSOS 25 Channel Driver Unit |
| DSOS 25 Channel Driver Unit (cont.) |
| DSOS - Calibration
& Zenith Angle Lookup Tables |
| DSOS Length Change Capability |
| DSOS Performance |
| The +/- 25 micron desired capability has been achieved | ||
| Power Consumption | ||
| Power Draw At Start Up = 4kWatts | ||
| Quiescent Power Draw = 840 Watts | ||
| Added Weight to Dish - 268 lbs | ||
| Approximate Weight of System on 3rd Floor - 1,994 lbs | ||
| First Glimmer - 692GHz
Rx 14% Improvement |
| First Light - SHARC2 27% Improvement |
| DSOS Performance - Feb. 2003 |
| DSOS - Performance SHARCII - April 2003 |
| DSOS - Performance 50% Peak, 18% FWHM - 2004 |
| DSOS - Performance 10 µm RMS - April 2005 |
| DSOS - Improvements 70% Improvement - July 2005 |
| SHARC2 Move from Cassegrain to N2 |
| DSOS - Improvements N2 Optimization |
| SHARC2 Observations Fomalhaut & Epsilon Eridani |
| SHARC2 Observations Star Formation |
| SHARC2 Observations M51/Whirlpool Galaxy |
| SHARC2 Observations Antennae Galaxies |
| SHARC2 Observations ARP 84 |
| High Redshift
Detection z ~4.4 |
| CSO SHARC2
Collaborations Variability of Sgr A* |
| Long-term | |
| Variability |
| CSO SHARC2
Collaborations Variability of Sgr A* (2) |
| DSOS Conclusion |
| Many new detections of weak and/or distant objects with SHARC2 and 850 GHz Receiver have been achieved with the help of the DSOS | |
| The DSOS consistently improves the aperture efficiency of the 10.4-meter Leighton Telescope in the 350 micron wavelength range | |
| The DSOS is the only working system of its kind in the world | |