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 | |